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In the paper, we proposed frequency-selective carrier coded aperture correlation holography (FSC-COACH). Incoherent frequency selection technique is introduced into coded aperture correlation holography for the first time, and mask scattering imaging of arbitrary branches is realized. This represents a novel form of non-visual imaging technology capable of effectively suppressing background noise and facilitating holographic separation and reconstruction beneath the obstruction of multiple opaque mediums. Experimental analysis explores the impact of virtual point spread function filter radius on the quality of reconstruction. Through the reconstruction of standard particles and the overlapping dual-path reconstruction of the USAF chart under mask obstruction, the feasibility of our technology is demonstrated. We are confident that the proposed approach will pioneer paradigm shifts in incoherent imaging, wavefront acquisition through scattering mediums, astronomical imaging, and rapid object recognition applications. • A new frequency selection method eliminates zero-order and conjugate terms in multiplexed coded aperture holography. • Multiplexed incoherent holograms can be stored or transmitted in compressed form, or optically reconstructed with reduced temporal resolution. • This method is effective for obtaining scattering medium wavefronts when static resolution falls short. [ABSTRACT FROM AUTHOR]

A total of seven qubits are in a maximally entangled state. Using such an entangled state as quantum channel is based on the construction requirements of quantum long-distance communication [Pan et al., Nature488, 185 (2012)]. Multi-party quantum channel (QC) should be studied. We put forward three deterministic bidirectional quantum controlled teleportation (BQCT) schemes. To be specific, BQCT can be realized between any two parties in a deterministic manner with another as the control. Alternatively, the BQCT capacity of such state in the given qubit distribution is thus essentially revealed by virtue of the schemes. [ABSTRACT FROM AUTHOR]

In this paper a tripartite quantum operation sharing scheme is put forward with a six-qubit entangled state presented by Chen et al. (Phys. Rev. A 74, 032324, 2006). Within the scheme the success probability of sharing the operation is deterministic. The scheme security is analyzed and thus confirmed. [ABSTRACT FROM AUTHOR]

Treating pancreatic ductal adenocarcinoma (PDAC) remains a major hurdle in the field of oncology. Less than half of patients respond to frontline chemotherapy and the pancreatic tumor microenvironment limits the efficacy of immunotherapeutic approaches. Targeted therapies could serve as effective treatments to enhance the clinical response rate. One potential therapeutic target is survivin, a protein that is normally expressed during embryonic and fetal development and has a critical impact on cell cycle control and apoptosis. In adulthood, survivin is not present in most normal adult cells, but is significantly re-expressed in tumor tissues. In PDAC, elevated survivin expression is correlated with treatment resistance and lower patient survival, although the underlying mechanisms of survivin's action in this type of cancer is poorly understood. Using patient derived xenografts of PDAC and their corresponding primary pancreatic cancer lines (PPCL-46 and PPCL-LM1) possessing increased expression of survivin, we aimed to evaluate the therapeutic response of a novel survivin inhibitor, UFSHR, with respect to survivin expression and the tumorigenic characteristics of PDAC. Cell viability and apoptosis analyses revealed that repressing survivin expression by UFSHR or YM155, a well-known inhibitor of survivin, in PPCLs effectively reduces cell proliferation by inducing apoptosis. Tumor cell migration was also hindered following treatment with YM155 and UFSHR. In addition, both survivin inhibitors, particularly UFSHR, effectively reduced progression of PPCL-46 and PPCL-LM1 tumors, when compared to the untreated cohort. Overall, this study provides solid evidence to support the critical role of survivin in PDAC progression and proposes a novel survivin inhibitor UFSHR that can become an alternative strategy for this type of cancer. [ABSTRACT FROM AUTHOR]

Each of three nodes in a quantum network has two qubits. The total six qubits are in a maximally entangled state [Helwig et al., Phys. Rev. A 86, 052335 (2012)]. Using such an entangled state as quantum channel, we put forward three deterministic bidirectional quantum-controlled teleportation (BQCT) schemes. To be specific, BQCT can be realized between any two nodes in a deterministic manner with another as the control. Alternatively, the BQCT capacity of such state in the given qubit distribution is thus essentially revealed by virtue of the schemes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two categories of water-soluble polymeric corrosion inhibitors (CIs) were prepared. • Two facile routes for synthesizing of polymeric CIs were contributed. • Bonding of PEG segment is a promising strategy for synthesizing of water-soluble CIs. • Both the PEG segment and the heterocyclic groups contribute to corrosion inhibition. • The inhibition efficiency was improved with the introduction of alkyl groups. In this work, two categories of water-soluble polymeric corrosion inhibitors (CIs) are contributed. These CIs are composed by polyethylene glycol (PEG) middle segment and oleic imidazoline (or thiophene) end groups, respectively labeled as OIM-PEG-OIM and Th-PEG-Th. Two facile synthetic strategies involve epoxy-amino reaction and thiol-acrylate Michael addition were employed. Both Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy verified that a series of target products were successfully obtained. The solution transmittance measurements indicated that with the increase of the PEG segment length, the water solubility of CIs enhanced. And these obtained CIs exhibit somewhat surface activity and could reduce the solution surface tensions to a certain extent. The inhibition efficiencies of these CIs for mild steel in HCl medium were evaluated by weight loss measurements, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). It was found that both OIM-PEG-OIM and Th-PEG-Th show an improved corrosion inhibition efficiency as compared to PEG. And as compared to heterocyclic compounds, introduction of PEG segment showed a negligible influence on their performances. Both CIs can form chemisorption on the metal surface, and the adsorption process follow Langmuir adsorption mechanism. OIM-PEG-OIM exhibit superior inhibition performance and stability as compared to Th-PEG-Th, which can be attributed to the fact that OIM-PEG-OIM bearing two long hydrophobic alkyl end groups. Scanning electron microscope (SEM) observations as well as atomic force microscopy (AFM) measurements also confirmed both OIM-PEG-OIM and Th-PEG-Th could serve as water-soluble CIs for mild steel. [ABSTRACT FROM AUTHOR]

Polybutadiene with the simultaneous presence of hydroxyl end-groups and pendant carboxyl side groups was successfully synthesized by combination of living anionic polymerization and blue light photocatalytic thiol-ene “click” reaction. Firstly, hydroxyl-terminated polybutadiene (HTPB) with high content of 1,4-butadiene unit was synthesized by living anionic polymerization using hydroxy-protected initiator, and followed by de-protection. Then, double bonds in backbone of HTPB were modified into pendant carboxyl side groups by blue light photocatalytic thiol-ene “click” reaction using Ru(bpy) 3 Cl 2 and p -toluidine as photoredox catalysts. The blue light photocatalytic thiol-ene reaction exhibit high-efficiency, and all the unsaturated bonds were modified after reacting for 5 h, in spite of that in-chain double bonds in 1,4-butadiene units are much less reactive than vinyl groups in 1,2-butadiene units. When all the double bonds were modified, the structure of resulting polymer can be deemed as carboxyl functionalized hydroxyl-terminated polyethylene. Furthermore, the solution properties of resulting polymer have been investigated by various technologies. The results showed carboxyl functionalized hydroxyl-terminated polyethylene experience a dissolution-assembly-aggregation transition process with pH value of solution decreased from 12.0 to 2.0. The mechanism of this pH-triggered phase transition behavior was supposed to depend on the ionization of carboxyl side groups at varying pH values. [ABSTRACT FROM AUTHOR]

Oxazoline-containing ligands have been widely employed in numerous asymmetric catalytic reactions. Pyridine-oxazoline-type ligands, a class of hybrid ligands, were designed earlier than bisoxazoline and phosphine-oxazoline ligands; however, their unique properties have only been discovered recently. Pyridine-oxazoline-type chiral ligands are rapidly becoming popular for use in asymmetric catalysis, especially for several new and efficient asymmetric methodologies. Several types of challenging asymmetric reactions have been discovered recently using pyridine-oxazoline-type ligands showing their special properties and potential for future application in a wide range of new catalytic methodologies. This review provides an overview of this field, with the aim of highlighting both ligand design and synthetic methodology development. [ABSTRACT FROM AUTHOR]

The design and synthesis of chiral ligands plays an important role in asymmetric catalytic reactions. Over the past decades, various types of chiral phosphine‐oxazolines (PHOX ligands) have been developed and have greatly advanced the field of asymmetric catalysis. Novel chiral PHOX ligand with an axis‐unfixed biphenyl backbone, developed by our group, have shown interesting coordination behavior and excellent chiral inducing ability in various transition‐metal‐catalyzed asymmetric reactions. This personal account focuses on our developed axis‐unfixed biphenylphosphine‐oxazoline ligand (BiphPHOX), including an overview of its design and applications, which will provide inspiration for the exploration of novel ligands and related reactions. [ABSTRACT FROM AUTHOR]

• In this letter, we introduce the concept of frequency selection into the field of incoherent digital holography. It is also the worldí¯s first demonstration of incoherent optical frequency selection technology. Theoretically it is possible to extend the number of object waves carrying object information to infinite dimensions. • Such multiplexed incoherent holograms can be stored or sent in their compressed form or reconstructed in an optical method with reduced temporal resolution. • We believe that our work paves the way for wide-field super-resolution TPFS-FINCH for biomedical imaging. This is effective for cases where the spatial resolution of a static observer is not sufficient. We proposed a new incoherent optical frequency selection method called two-pack frequency-selective (TPFS) incoherent holography, which compresses two on-axis holograms into a single multiplexed on-axis hologram without loss of magnification and resolution. The spectrum we want to reconstruct is intercepted by multiple confounding correlation terms in the spatial frequency domain. The background bias term and conjugate term can be effectively suppressed. This work is the first to attempt a multiplexed reconstruction in the field of incoherent light. Experiment results highlight the potential of the proposed method in several areas, such as compressed holography and extended field of view imaging. [ABSTRACT FROM AUTHOR]

ABSTRACT A novel aromatic acetal-based acid-labile monomer 2-phenyl-5-ethyl-5-acryloxymethyl-1,3-dioxacyclohexane (HEDPA) was synthesized and polymerized by reversible addition fragmentation chain transfer (RAFT) polymerization using alkynyl functional chain transfer agent (CTA-Alk). Afterward, a series of amphiphilic diblock copolymers composed of fixed hydrophobic poly(2-phenyl-5-ethyl-5-acryloxymethyl-1,3-dioxacyclohexane) (PDAEP) segments and various lengths of hydrophilic mPEG segments were prepared through click reaction between alkynyl-terminated PDAEP and azido-terminated mPEG. The self-assembly behaviors of the diblock copolymers were investigated by dynamic light scattering (DLS), transmission electron microscopy (TEM), fluorescence spectroscopy, and 1H NMR. These results indicated that the diblock copolymers could self-assemble into nano-sized micelles with PDAEP cores and PEG coronas in aqueous solution. DLS, fluorescence spectroscopy and UV-vis spectroscopy were used to monitor the pH-triggered assembly/disassembly transition of the micelles. These results showed that the assembly/disassembly transition behaviors of the diblock copolymers micelles can be adjusted by changing the lengths of the mPEG segments. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 1537-1547 [ABSTRACT FROM AUTHOR]

The transition metal-catalyzed allylic substitution of unactivated allylic substrates (allylic alcohols, allylic ethers and allylic amines) is rapidly becoming an important area of research. There are several advantages to using these substrates in allylic substitution reactions: the use of unactivated alcohols minimizes the production of waste by-products and reaction steps; and allylic ethers and allylic amines are useful substrates because of their stability and their presence in numerous biologically active compounds. Research in this field has therefore gained widespread attention for promoting the development of efficient and environmentally benign procedures for the formation of C–C, C–N and C–O bonds. [ABSTRACT FROM AUTHOR]

[Display omitted] • A versatile strategy for synthesis of hyperbranched ionic surfactants was provided. • A series of hyperbranched surfactants composed by polyether skeleton and various ionic side groups were synthesized. • Hyperbranched ionic surfactants obtained in this work exhibit low Krafft temperatures. • Latex prepared using hyperbranched anionic surfactant as a stabilizer exhibit improved tolerance to salinity. A versatile strategy involves anionic ring-opening polymerization (AROP) and thiol-ene reaction was contributed for the construction of hyperbranched ionic surfactants. A series of hyperbranched surfactants composed of polyether skeleton and various ionic side groups such as anion, cation and zwitterion were synthesized and labeled as HPE anionic , HPE cationic and HPE zwitterionic , respectively. The chemical structures of all the intermediate and final products were verified by means of fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. The surface and interfacial tension reduction performances of three obtained ionic surfactants were systematically investigated. And the results confirmed all the resultant surfactants could effectively reduce the surface and interfacial tension of the solution, and the CMC values were all determined approximately to 0.1 mg/mL. Meanwhile, three surfactants exhibit relatively low Krafft temperatures (below 6 ℃) and good wettability to oil-wetted surface. To further explore their promising applications, HPE anionic was proposed for use as a stabilizer in emulsion polymerization. Dynamic light scattering (DLS) measurements as well as transmission electron microscope (TEM) observation confirmed well-defined latex was obtained indeed. Moreover, as compared to latex synthesized by using the traditional small molecule compound surfactants, latex synthesized using HPE anionic as stabilizer exhibit improved tolerance to salinity. This beneficial result is probably caused by the special hyperbranched structure of HPE anionic , which contributes both electrostatic repulsion and steric hindrance drive force for the stabilization of latex particles. [ABSTRACT FROM AUTHOR]

Sly as Nicox: A palladium‐catalyzed addition of arylboronic acids to ketimines has been developed to efficiently provide products in up to 99 % yield and 96 % ee. The reactions could be run under aerobic conditions and with unpurified trifluoroethanol (TFE). A pyrrolidine compound bearing a chiral α‐tertiary amine was synthesized in several steps without loss of enantioselectivity. TFA=trifluoroacetate. [ABSTRACT FROM AUTHOR]

Nicht empfindlich: Die palladiumkatalysierte Addition von Arylboronsäuren an Ketimine liefert die Produkte in Ausbeuten bis 99 % und mit bis zu 96 % ee. Die Reaktion findet in Gegenwart von Luft in nicht gereinigtem Trifluorethanol (TFE) statt. Ein Pyrrolidinderivat mit Stereozentrum in α ‐ Stellung zu einer tertiären Aminfunktion wurde in mehreren Schritten ohne Verlust an Enantioselektivität synthetisiert. TFA=Trifluoracetat. [ABSTRACT FROM AUTHOR]

Not to be out PhOXed! The title reaction provides a new approach to chiral succinimide derivatives with excellent yields and ee values by using a low catalyst loading (0.05 mol %) and mild reaction conditions. Chiral 3‐benzyl pyrrolidines and 1‐hydroxypyrrolidine‐2,5‐diones, important structural motifs in natural products and pharmaceuticals, could be readily prepared. BARF−=tetrakis[3,5‐bis(trifluoromethyl)phenyl]borate. [ABSTRACT FROM AUTHOR]

Chirale Succinimid ‐ Derivate sind durch die Titelreaktion mit ausgezeichneten Ausbeuten und Enantioselektivitäten schon bei Zusatz einer geringen Katalysatormenge von 0.05 Mol ‐ % unter milden Bedingungen zugänglich. Wichtige Strukturmotive aus Natur ‐ und Wirkstoffen, namentlich chirale 3 ‐ Benzylpyrrolidine und 1 ‐ Hydroxypyrrolidin ‐ 2,5 ‐ dione, konnten problemlos erhalten werden. BARF−=Tetrakis[3,5 ‐ bis(trifluormethyl)phenyl]borat. [ABSTRACT FROM AUTHOR]

Dual catalysis is one of the most powerful strategies for the development of chemical reactions in organic synthesis. This strategy can be divided into cooperative catalysis, relay catalysis, and sequential catalysis according to the actual mode of operation and the communication between the catalysts. In recent years, such strategy has been applied in a large number of studies since it has the advantages of: 1) increasing reactivity and enabling challenging transformations; 2) offering a powerful way of controlling the stereoselectivity of asymmetric reactions, which is challenging for traditional catalytic systems; 3) catalyze the stereodivergent synthesis of molecules bearing one or more stereocenters from the same starting materials. This Perspective, which intends to introduce the reader to EurJOC special collection on Dual Catalysis , aims to summarize and introduce the different categories of dual catalysis and demonstrate their benefits in constructing new chemical bonds in a selective manner. Finally, current challenges and new trends in dual catalysis will be also presented. [ABSTRACT FROM AUTHOR]

N-Hydroxysuccinimidyl benzoate was prepared as a model compound of fluorescent probes. Its crystal structure was determined. The interlayer space between neighbored aromatic rings is inserted by the carbonyl group of succinimidyl moiety and the stacking distance between aromatic rings is as far as 5.9085Å. Labeling activity of carbonyl groups in N-hydroxysuccinimidyl benzoate was studied by AM1 semiempirical method and the result indicated that carbonyl group consisting of O4 and C5 was responsible for the labeling reaction center. [Copyright &y& Elsevier]

Abstract: We wished to prepare planar chiral compounds by the lithiation of acetal 2-ferrocenyl-(4S,5S)-bis(methoxymethyl)-1,3-dioxolane (1) with butyllithium followed by the reaction with an electrophile. However, the desired products were not observed and two unexpected products, 1-ferrocenyl-1-pentanol (4) of the nucleophilic attack product and 2-ferrocenyl-4,5-dimethylene-1,3-dioxolane (5) of the proton abstraction product, were isolated. Because the nucleophilic attack on acetal carbon is rarely reported so far and both products 4 and 5 may have some potential uses in organic synthesis, these unexpected reactions are investigated in detail. The mechanisms of these reactions are discussed. [Copyright &y& Elsevier]

Abstract: The synthesis of novel C 2-symmetric bisoxazoline ligands with an axial-unfixed biaryl backbone and different substituents at the oxazoline ring is reported. The diastereomer equilibrium of these ligands in solution and their complexation behavior with the copper(I) ion were studied. Their application in Cu-catalyzed cyclopropanation of styrene, with diazoacetate, was carried out and the effects of the biaryl backbone and the substituent on the oxazoline ring in the catalysis were examined. The best result was obtained with the ligand having a 1,1′-binaphthyl backbone and a t-butyl group on the oxazoline ring, which afforded 89% de and 96% de for the trans- and cis-products of the above asymmetric cyclopropanation reaction, respectively. [Copyright &y& Elsevier]

An efficient RuPHOX−Ru catalyzed asymmetric cascade hydrogenation of 3‐substituted chromones has been achieved under mild reaction conditions, affording the corresponding chiral 3‐substituted chromanols in high yields with excellent enantio‐ and diastereoselectivities (up to 99 % yield, >99 % ee and >20 : 1 dr). Control reactions and deuterium labelling experiments revealed that a dynamic kinetic resolution process occurs during the subsequent hydrogenation of the C=O double bond, which is responsible for the high performance of the asymmetric cascade hydrogenation. The resulting products allow for several transformations and it was shown that the protocol provides a practical and alternative strategy for the synthesis of chiral 3‐substituted chromanols and their derivatives. [ABSTRACT FROM AUTHOR]

Asymmetric sequential hydrogenations of α‐methylene γ‐ or δ‐keto carboxylic acids are established in one‐pot using a bimetallic Ru/Ru catalyst system, achieving the stereodivergent synthesis of all four stereoisomers of both chiral γ‐ and δ‐lactones with two non‐vicinal carbon stereocenters in high yields (up to 99%) and with excellent stereoselectivities (up to >99% ee and >20:1 dr). The compatibility of the two chiral Ru catalyst systems is investigated in detail, and it is found that the basicity of the reaction system plays a key role in the sequential hydrogenation processes. The protocol can be performed on a gram‐scale with a low catalyst loading (up to 11000 S/C) and the resulting products allow for many transformations, particularly for the synthesis of several key intermediates useful for the preparation of chiral drugs and natural products. [ABSTRACT FROM AUTHOR]

The construction of chiral motifs containing nonadjacent stereocenters in an enantio‐ and diastereoselective manner has long been a challenging task in synthetic chemistry, especially with respect to their stereodivergent synthesis. Herein, we describe a protocol that enables the enantio‐ and diastereoselective construction of 1,5/1,7‐nonadjacent tetrasubstituted stereocenters through a Pd/Cu‐cocatalyzed Heck cascade reaction. Notably, a C=C bond relay strategy involving the shift of the π‐allyl palladium intermediate was successfully applied in the asymmetric construction of 1,7‐nonadjacent stereocenters. The current method allows for the efficient preparation of chiral molecules bearing two privileged scaffolds, oxindoles and non‐natural α‐amino acids, with good functional group tolerance. The full complement of the four stereoisomers of products bearing 1,5/1,7‐nonadjacent stereocenters could be readily accessed by a simple combination of two chiral metal catalysts with different enantiomers. [ABSTRACT FROM AUTHOR]

In recent years, a great deal of work has been devoted to the development of thermoresponsive polymers that can be made into new types of smart materials. In this paper, a branched polymer, HTPB-g-(PNIPAM/PEG), with polyolefin chain segments as the backbone and having polyethylene glycol (PEG) and poly(N-isopropylacrylamide) (PNIPAM) as side chains was synthesized by ATRP and click reactions using N3-HTPB-Br as the macroinitiator. This initiator was designed and synthesized using hydroxyl-terminated polybutadiene (HTPB) as the substrate. The temperature-responsive behavior of the branched polymer was investigated. The lower critical solution temperature (LCST) of the branched polymer was determined by ultraviolet and visible spectrophotometry (UV-vis) and was found to be 35.2 °C. The relationship between the diameter size of micelles and temperature was determined by dynamic light scattering (DLS). It was found that the diameter size changed at 36 °C, which was nearly consistent with the result obtained by UV-vis. The results of the study indicate that HTPB-g-(PNIPAM/PEG) is a temperature-responsive polymer. At room temperature, the polymer can self-assemble into composite micelles, with the main chain as the core and the branched chain as the shell. When the temperature was increased beyond LCST, the polyolefin main chain along with the PNIPAM branched chain assembled to form the nucleus, and the PEG branched chain constituted the shell. [ABSTRACT FROM AUTHOR]

• A novel dispersant with topological structure was developed based on humic acid. • Surface acylation reaction combine with ATRP technology were employed. • Novel dispersant exhibits superior dispersing and stabilizing performances. • Steric hindrance is crucially important for the dispersion of coal particles. This work reports the synthesis and performance of a novel dispersant for coal water slurry (CWS). The dispersant is derived from humic acid (HA) and has a topological structure, named humic acid- graft -poly(sodium styrene sulfonate) (HA- g -PSSNa). A series of HA- g -PSSNa with simultaneous presence of hydrophobic humic acid skeleton and hydrophilic poly(sodium styrene sulfonate) side chains were synthesized via surface acylation reaction of HA and followed by atom transfer radical polymerization. The structure and chemical composition of HA- g -PSSNa were verified by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Scanning electron microscopy observation suggests that the incorporation of PSSNa segments onto HA skeleton remarkably affects its morphology. The performances of CWS prepared using HA- g -PSSNa, PSSNa, and naphthalene sulfonic formaldehyde condensate (NSF) as dispersants were studied and systematically compared using various technologies. The results show that the slurry-making performance of HA- g -PSSNa enhanced with the increase in the length of PSSNa side chains. In the case of HA- g -PSSNa with appropriate PSSNa chain length, the CWS prepared using HA- g -PSSNa as dispersant exhibits excellent apparent viscosity as well as static stability, even superior to those of PSSNa and NSF. The dispersing and stabilizing mechanism of HA- g -PSSNa is proposed as follows: When used as a dispersant for CWS, HA skeleton provides sufficient hydrophobic interaction to coal surface and drives the adsorption of HA- g -PSSNa molecules. Hydrophilic PSSNa side chains are oriented to water, thus forming a dense electrical layer and steric hindrance surrounding the coal particles. Accordingly, the aggregation of coal particles was suppressed. [ABSTRACT FROM AUTHOR]

Abstract: The X-ray crystal structure of anthraquinone-1,5-dithiol has been determined. The compound C14H8O2S2 is monoclinic in Pc with a =3.8625(8)Å, b =10.395(2)Å, c =13.734(3)Å, β =93.609(4)°, V =550.31(19)Å3, D calc =1.643g/cm3 and Z =2. The crystal packing scheme indicates a π–π interaction. An intermolecular hydrogen bond of sp2C–H⋯S has been found between the H4 atom and the S2 atom. [Copyright &y& Elsevier]

Fluorinated amino acids and related peptides/proteins have been found widespread applications in pharmaceutical and agricultural compounds. However, strategies for introducing a C−F bond into amino acids in an enantioselective manner are still limited and no such asymmetric catalysis strategy has been reported. Herein, we have successfully developed a Pd/Cu/Li ternary system for stereodivergent synthesis of chiral fluorinated amino acids. This method involves a sequential desymmetrization of geminal difluoromethylenes and allylic substitution with amino acid Schiff bases via Pd/Li and Pd/Cu dual activation, respectively. A series of non‐natural amino acids bearing a chiral allylic/benzylic fluorine motif are easily synthesized in high yields with excellent regio‐, diastereo‐, and enantioselectivities (up to >20 : 1 dr and >99 % ee). A density functional theory (DFT) study revealed the F−Cu interaction of the allylic substrate and the Cu catalyst significantly influence the stereoselectivity. [ABSTRACT FROM AUTHOR]

Fluorinated amino acids and related peptides/proteins have been found widespread applications in pharmaceutical and agricultural compounds. However, strategies for introducing a C−F bond into amino acids in an enantioselective manner are still limited and no such asymmetric catalysis strategy has been reported. Herein, we have successfully developed a Pd/Cu/Li ternary system for stereodivergent synthesis of chiral fluorinated amino acids. This method involves a sequential desymmetrization of geminal difluoromethylenes and allylic substitution with amino acid Schiff bases via Pd/Li and Pd/Cu dual activation, respectively. A series of non‐natural amino acids bearing a chiral allylic/benzylic fluorine motif are easily synthesized in high yields with excellent regio‐, diastereo‐, and enantioselectivities (up to >20 : 1 dr and >99 % ee). A density functional theory (DFT) study revealed the F−Cu interaction of the allylic substrate and the Cu catalyst significantly influence the stereoselectivity. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Skipped dienes are of great importance but remain challenging to synthesize because of the presence of a sp3 hybrid carbon between the two alkenes. Herein, we have developed the first nickel‐catalyzed regio‐, (E)‐stereo‐ and linear‐selective ring‐opening/cross‐coupling reaction of vinylaziridines with organoboronic acids under mild conditions to construct various skipped aminodienes. The reaction exhibits wide functional‐group compatibility, and could be adapted for the introduction of skipped aminodiene functionality into bioactive molecules. In addition, the reaction could be carried out on a gram‐scale, delivering the ring‐opening products in high yields and with linear‐selectivity (90% yield, l : b >20 : 1). Furthermore, DFT calculations and mechanistic experiments provided detailed insights into the mechanism. [ABSTRACT FROM AUTHOR]

Synergistic Pd/Cu catalysis has been utilized in the Sonogashira reaction since 1975. However, this strategy has not received much attention from the organic chemist community until recently. Synergistic Pd/Cu catalysis is becoming a proficient method for the development of catalytic reactions, including several new and efficient cross‐coupling reactions. Additionally, several challenging asymmetric reactions, including stereodivergent synthesis, have been discovered by the combined use of a chiral metal catalyst and a second achiral metal catalyst or two chiral metal catalysts. This review provides an overview of this field, with the aims of highlighting both the development of synergistic Pd/Cu catalysis in organic synthesis and the reaction mechanisms involved in this research area. [ABSTRACT FROM AUTHOR]

This paper summarizes the application of the chiral ligand DTBM-SegPHOS in asymmetric catalytic hydrogenation reactions. DTBM-SegPHOS exhibits pronounced catalytic activity and enantioselectivity due to its high electron density and steric bulk. Indeed, it often performs better in reactions in which traditionally used ligands provide poor results. According to the impressive influence of the t-Bu groups of DTBM-SegPHOS and the resulting interactions with various substrates, new substrates bearing t-Bu groups were studied in asymmetric hydrogenations which were not previously possible. The ligand QuinoxP*, which possesses similar structural features to that of DTBM-SegPHOS, was employed for the hydrogenation of such substrates with the best results. The mechanistic studies prove that the unique catalytic behaviors of the complexes of these ligands in asymmetric hydrogenation are a result of the extensive network of weakly attractive interactions between the catalyst and substrate in the transition states. An overview of these impressive ligands in various asymmetric hydrogenations using different transition metal catalysts is provided. [ABSTRACT FROM AUTHOR]

Axis-unfixed, biphenylphosphine-oxazoline, iridium, asymmetric hydrogenation, alkenes Cover Picture: Axis-Unfixed Biphenylphosphine-Oxazoline Ligands: Design and Applications in Asymmetric Catalytic Reactions (Chem. Rec. 10/2023) Keywords: axis-unfixed; biphenylphosphine-oxazoline; iridium; asymmetric hydrogenation; alkenes EN axis-unfixed biphenylphosphine-oxazoline iridium asymmetric hydrogenation alkenes 1 1 1 10/16/23 20231001 NES 231001 The Front Cover depicts the applications of axis-unfixed biphenylphosphine-oxazoline ligands, which were designed based on dihedral angle regulation, in transition-metal-catalyzed asymmetric hydrogenation, asymmetric allylic substitution, and asymmetric addition reactions. [Extracted from the article]

An iridium‐catalyzed remote site‐switchable hydroarylation of alkenes was reported, delivering the products functionalized at the subterminal methylene and terminal methyl positions on an alkyl chain controlled by two different ligands, respectively, in good yields and with good to excellent site‐selectivities. The catalytic system showed good functional group tolerance and a broad substrate scope, including unactivated and activated alkenes. More importantly, the regioconvergent transformations of mixtures of isomeric alkenes were also successfully realized. The results of the mechanistic studies demonstrate that the reaction undergoes a chain‐walking process to give an [Ar−Ir−H] complex of terminal alkene. The subsequent processes proceed through the modified Chalk–Harrod‐type mechanism via the migratory insertion of terminal alkene into the Ir−C bond followed by C−H reductive elimination to afford the hydrofunctionalization products site‐selectively. [ABSTRACT FROM AUTHOR]

An iridium‐catalyzed remote site‐switchable hydroarylation of alkenes was reported, delivering the products functionalized at the subterminal methylene and terminal methyl positions on an alkyl chain controlled by two different ligands, respectively, in good yields and with good to excellent site‐selectivities. The catalytic system showed good functional group tolerance and a broad substrate scope, including unactivated and activated alkenes. More importantly, the regioconvergent transformations of mixtures of isomeric alkenes were also successfully realized. The results of the mechanistic studies demonstrate that the reaction undergoes a chain‐walking process to give an [Ar−Ir−H] complex of terminal alkene. The subsequent processes proceed through the modified Chalk–Harrod‐type mechanism via the migratory insertion of terminal alkene into the Ir−C bond followed by C−H reductive elimination to afford the hydrofunctionalization products site‐selectively. [ABSTRACT FROM AUTHOR]

A highly chemoselective earth‐abundant transition metal copper catalyzed asymmetric hydrogenation of C=O bonds of exocyclic α,β‐unsaturated pentanones was realized using H2. The desired products were obtained with up to 99 % yield and 96 % ee (enantiomeric excess) (99 % ee, after recrystallization). The corresponding chiral exocyclic allylic pentanol products can be converted into several bioactive molecules. The hydrogenation mechanism was investigated via deuterium‐labelling experiments and control experiments, which indicate that the keto‐enol isomerization rate of the substrate is faster than that of the hydrogenation and also show that the Cu−H complex can only catalyze chemoselectively the asymmetric reduction of the carbonyl group. Computational results indicate that the multiple attractive dispersion interactions (MADI effect) between the catalyst with bulky substituents and substrate play important roles which stabilize the transition states and reduce the generation of by‐products. [ABSTRACT FROM AUTHOR]

A highly chemoselective earth‐abundant transition metal copper catalyzed asymmetric hydrogenation of C=O bonds of exocyclic α,β‐unsaturated pentanones was realized using H2. The desired products were obtained with up to 99 % yield and 96 % ee (enantiomeric excess) (99 % ee, after recrystallization). The corresponding chiral exocyclic allylic pentanol products can be converted into several bioactive molecules. The hydrogenation mechanism was investigated via deuterium‐labelling experiments and control experiments, which indicate that the keto‐enol isomerization rate of the substrate is faster than that of the hydrogenation and also show that the Cu−H complex can only catalyze chemoselectively the asymmetric reduction of the carbonyl group. Computational results indicate that the multiple attractive dispersion interactions (MADI effect) between the catalyst with bulky substituents and substrate play important roles which stabilize the transition states and reduce the generation of by‐products. [ABSTRACT FROM AUTHOR]

In this paper, the effects of HTPBs with different main-chain microstructures on their triblock copolymers and polyurethane properties were investigated. Three polyether-modified HTPB triblock copolymers were successfully synthesized via a cationic ring-opening copolymerization reaction using three HTPBs with different microstructures prepared via three different polymerization methods as the macromolecular chain transfer agents and tetrahydrofuran (THF) and propylene oxide (PO) as the copolymerization monomers. Finally, the corresponding polyurethane elastomers were prepared using the three triblock copolymers as soft segments and toluene diisocyanate (TDI) as hard segments. The results of an analysis of the triblock copolymers showed that the triblock copolymers had lower viscosity and glass transition temperature (Tg) values as the HTPB 1,2 structure content decreased, although the effect on the thermal decomposition temperature was not significant. An analysis of the polyurethane elastomers revealed that as the content of the 1,2 structure in HTPB increased, its corresponding polyurethane elastomers showed a gradual increase in breaking strength and a gradual decrease in elongation at break. In addition, PU-1 had stronger crystallization properties compared to PU-2 and PU-3. However, the differences in the microstructures of the HTPBs did not seem to have much effect on the surface properties of the polyurethane elastomers. [ABSTRACT FROM AUTHOR]

The skeletons of chiral tetrasubstituted allenes bearing a vicinal all‐carbon quaternary stereocenter are of importance but still challenging to synthesize. Herein, we report enantio‐ and diastereoselective γ‐additions of 1‐alkynyl ketimines with dual‐copper‐catalysis under mild conditions, affording chiral tetrasubstituted α‐amino allenoates bearing a vicinal all‐carbon quaternary stereocenter in high yields (up to 99 % yield) with excellent enantioselectivities (up to 99 % ee) and diastereoselectivities (up to >20 : 1 dr). Importantly, the stereodivergent synthesis of the products was realized by the asymmetric γ‐addition reaction and the Grignard reagent promoted epimerization. Moreover, the dual‐copper‐catalyzed γ‐addition reactions were smoothly applied to a gram‐scale reaction and adopted to introduce chiral tetrasubstituted allenyl moieties into bioactive molecules. Mechanistic experiments and density functional theory (DFT) calculations demonstrated that the asymmetric γ‐addition reactions were catalyzed by double chiral copper catalysts. [ABSTRACT FROM AUTHOR]

The skeletons of chiral tetrasubstituted allenes bearing a vicinal all‐carbon quaternary stereocenter are of importance but still challenging to synthesize. Herein, we report enantio‐ and diastereoselective γ‐additions of 1‐alkynyl ketimines with dual‐copper‐catalysis under mild conditions, affording chiral tetrasubstituted α‐amino allenoates bearing a vicinal all‐carbon quaternary stereocenter in high yields (up to 99 % yield) with excellent enantioselectivities (up to 99 % ee) and diastereoselectivities (up to >20 : 1 dr). Importantly, the stereodivergent synthesis of the products was realized by the asymmetric γ‐addition reaction and the Grignard reagent promoted epimerization. Moreover, the dual‐copper‐catalyzed γ‐addition reactions were smoothly applied to a gram‐scale reaction and adopted to introduce chiral tetrasubstituted allenyl moieties into bioactive molecules. Mechanistic experiments and density functional theory (DFT) calculations demonstrated that the asymmetric γ‐addition reactions were catalyzed by double chiral copper catalysts. [ABSTRACT FROM AUTHOR]

Thirty-six of novel compounds 2-substituted-1-(2-morpholinoethyl)-1 H -naphtho[2,3- d ]imidazole-4,9-diones, bearing a N -(2-morpholinoethyl) group and a 2-substituted imidazole segment on a naphthoquinone skeleton, were designed, synthesized and tested as anticancer agents. Cytotoxicity was evaluated in vitro against three human cancer cell lines: human breast carcinoma cell line (MCF-7), human cervical carcinoma cell line (Hela), and human lung carcinoma cell line (A549); and one normal cell line: mouse fibroblast cell line (L929). Among them, the compound 2-(3-chloro-4-methoxyphenyl)-1-(2-morpholinoethyl)-1 H -naphtho[2,3- d ]imidazole-4,9-dione showed good antiproliferative activity against MCF-7, Hela and A549 (IC 50 values are equal to 10.6 μM, 8.3 μM and 4.3 μM respectively) and low cytotoxicity to L929 (IC 50 value is equal to 67.3 μM). [ABSTRACT FROM AUTHOR]

Review: recent developments; 94 refs. [ABSTRACT FROM AUTHOR]

An abstract of the article "Synthesis of Heterocycles via Palladium-Catalyzed Wacker-Type Oxidative Cyclization Reactions of Hydroxy- and Amino-Alkene" by N. A. Butt and W. Zhang is presented.

Using the diphosphine‐cobalt‐zinc catalytic system, an efficient asymmetric hydrogenation of internal simple enamides has been realized. In particular, the Ph‐BPE ligand can achieve convergent asymmetric hydrogenation of E/Z‐substrates. High yields and excellent enantioselectivities were obtained for both acyclic and cyclic enamides bearing α‐alkyl‐β‐aryl, α‐aryl‐β‐aryl, and α‐aryl‐β‐alkyl substituents. Hydrogenated products can be applied for the synthesis of useful chiral drugs such as Arfromoterol, Rotigotine, and Norsertraline. In addition, reasonable catalytic mechanism and stereocontrol mode are proposed based on DFT calculations. [ABSTRACT FROM AUTHOR]

Using the diphosphine‐cobalt‐zinc catalytic system, an efficient asymmetric hydrogenation of internal simple enamides has been realized. In particular, the Ph‐BPE ligand can achieve convergent asymmetric hydrogenation of E/Z‐substrates. High yields and excellent enantioselectivities were obtained for both acyclic and cyclic enamides bearing α‐alkyl‐β‐aryl, α‐aryl‐β‐aryl, and α‐aryl‐β‐alkyl substituents. Hydrogenated products can be applied for the synthesis of useful chiral drugs such as Arfromoterol, Rotigotine, and Norsertraline. In addition, reasonable catalytic mechanism and stereocontrol mode are proposed based on DFT calculations. [ABSTRACT FROM AUTHOR]

Chiral α,β‐unsaturated γ‐lactams bearing simple γ‐ substituents are found in biologically active molecules and natural products, however, their synthesis still remains difficult. Herein, we report an efficient kinetic resolution (KR) of γ‐substituted α,β‐unsaturated γ‐lactams via a Cu‐catalyzed asymmetric boron conjugate addition, which also leads to the efficient synthesis of chiral β‐hydroxy‐γ‐lactams with β,γ‐stereogenic carbon centers. The KR proceeded smoothly with a wide range of γ‐alkyl or aryl substituted substrates including those bearing aromatic heterocycles and different N‐protected substrates in up to 347 of s value. Their highly versatile transformations, synthetic utility in biologically active molecules, and inhibitory activities against cisplatin‐sensitive ovarian cancer cell A2780 have also been demonstrated. Differing from the well‐known mechanism involving Cu−B species in Cu‐catalyzed boron conjugate additions, our mechanistic studies using density functional theory (DFT) calculations and experiments indicate that a Lewis acid CuI‐catalyzed mechanism is the likely pathway in the catalytic reaction. [ABSTRACT FROM AUTHOR]

Chiral α,β‐unsaturated γ‐lactams bearing simple γ‐ substituents are found in biologically active molecules and natural products, however, their synthesis still remains difficult. Herein, we report an efficient kinetic resolution (KR) of γ‐substituted α,β‐unsaturated γ‐lactams via a Cu‐catalyzed asymmetric boron conjugate addition, which also leads to the efficient synthesis of chiral β‐hydroxy‐γ‐lactams with β,γ‐stereogenic carbon centers. The KR proceeded smoothly with a wide range of γ‐alkyl or aryl substituted substrates including those bearing aromatic heterocycles and different N‐protected substrates in up to 347 of s value. Their highly versatile transformations, synthetic utility in biologically active molecules, and inhibitory activities against cisplatin‐sensitive ovarian cancer cell A2780 have also been demonstrated. Differing from the well‐known mechanism involving Cu−B species in Cu‐catalyzed boron conjugate additions, our mechanistic studies using density functional theory (DFT) calculations and experiments indicate that a Lewis acid CuI‐catalyzed mechanism is the likely pathway in the catalytic reaction. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: TBAJ‐876, developed by TB Alliance, a novel anti‐tuberculosis‐specific drug, has entered Phase II clinical trials. Herein, the first asymmetric synthesis of TBAJ‐876 has been realized using synergistic Li/Li catalysis with excellent yield of 95% and 88 : 12 er (99.6 : 0.4 er, 10 : 1 dr after simple recrystallization). Furthermore, DFT calculations and 7Li‐NMR analysis illustrated the mechanism of the synergistic reaction: a chiral Li‐complex activates the nucleophile to control the stereoselectivity, while the other achiral Li‐complex activates the electrophile to catalyze the carbonyl addition reaction. Additionally, this protocol has been successfully carried out at 5 gram‐scale, showing its industrial potential. [ABSTRACT FROM AUTHOR]

The hydrophilic surface and developed pore structure restricted the application of abundant low rank coals (LRC) for the preparation of coal water slurry (CWS) with high concentration. In this work, emulsified asphalt was applied as an effective and low cost modifier to modify coal surface and improve the slurry making performance of LRC. The successful modification was verified by various technologies, such as chemical titration, X-ray photoelectron spectroscopy (XPS) and Zeta potential measurements. The results revealed that the oxygen containing groups located at LRC surface were covered by emulsified asphalt, which further caused the decrease of Zeta potential. The influence of modification on wettability of coal was also evaluated by contact angle and moisture re-adsorption. It showed that the hydrophobicity of LRC significantly increased, which is accompanied with the reduction of inherent moisture. Besides, the results of nitrogen adsorption and scanning electron microscope (SEM) verified that the hydrophobic layer formed by emulsified asphalt blocked the pores of LRC. The modified LRC also exhibited better adsorption ability to the widely used anionic dispersant naphthalene sulfonate formaldehyde condensate (NSF) than that of raw coal (RC) and microwave dehydration coal (MDC). Anyhow, modified LRC possessed the characteristics as high rank coal. Afterwards, modified coal was applied to prepare CWS. The results showed that CWS prepared by modified LRC exhibited superior slurry making performance as compared to RC and MDC. The surface modification reduced the inherent moisture and promoted the adsorption of dispersant, which increased the free water amount and enhanced electrostatic repulsion and steric hindrance among coal particles. Accordingly, the maximum concentration for CWS increased, and the static stability enhanced. [ABSTRACT FROM AUTHOR]

The article focuses on a study titled "A Palladium-Catalyzed Enantioselective Addition of Arylboronic Acids to Cyclic Ketimines," that was published in the 2013 issue of the journal "Angewandte Chemie International Edition."