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Optimized conditions including the phosphine ligand (PPC) allow the efficient synthesis of trifluoromethylstyrenes from fluorinated vinyl chlorides and arylboronic acids.

A facile and practical synthetic route of unsymmetrical 1,3-diynes via the PdCl/CuI catalyzed oxidative coupling of two different terminal alkynes has been developed by using 3-(diphenylphosphino)propanoic acid as a ligand in the presence of oxygen. This system is suitable for not only aromatic alkynes but also heteroaromatic and aliphatic alkynes which were transformed into the corresponding unsymmetrical 1,3-diynes in moderate to good yields at room temperature. Moreover, the unsymmetrical 1,3-diynes were also obtained on a multi-gram scale. Mechanistic studies suggest that oxygen plays a key role in the catalytic cycles.

Five new altenusin derivatives, compounds 1–5, along with six known analogues 6–11, were isolated from a culture of the endophytic fungus Alternaria sp. SK6YW3L, which was isolated from a fresh fruit of the mangrove plant Sonneratia caseolaris, collected from the South China Sea. Their structures were elucidated by analysis of 1D and 2D NMR and high resolution mass spectroscopic data. The absolute configurations of compounds 1–3 and 5 were assigned by quantum chemical calculations of the electronic circular dichroic (ECD) spectra. Structures of compounds 1 and 4 were further confirmed by single-crystal X-ray diffraction experiments using Cu Kα radiation. All isolated compounds were evaluated for α-glucosidase inhibitory activity, and compounds 2, 3 and 9 exhibited moderate inhibitory activity. The plausible biosynthetic pathways for all the compounds were proposed.

Highly efficient kinetic resolution of 2H-azirines by an asymmetric imine amidation was achieved in the presence of a chiral N,N'-dioxide/Sc(III) complex, thus providing a promising method to obtain the enantioenriched 2H-azirine derivatives and protecting-group free aziridines at the same time. It is rare to find an example of N1 of an oxindole participating in a reaction over C3. Moreover, chiral 2H-azirines were stereospecifically transformed into an unprotected aziridine and α-amino ketone.

1,2-Diketones were synthesized by the oxidation of corresponding alkynes using air as the oxidant under metal-free conditions upon irradiation of blue light. A cheap and readily available organic dye, eosin Y, was used as the photocatalyst. For various substituents on the aryl ring, the reaction proceeded smoothly to give the dicarbonylation products in moderate to good yields. Some oxidation-sensitive groups, such as formyl and the carbon–carbon double bond, were tolerated under the developed reaction conditions.

The oxysulfonylation of aryl-substituted allenes (I) with arylsulfinic acids (II) proceeds readily leading to 2-sulfonyl allylic alcohols (III), whilst ester-substituted allene (VI) reacts with benzenesulfinic acid to afford terminal alkene (VII).

Reported is an efficient synthesis of α-fluoroketones by insertion of hydrogen fluoride (HF) into the gold carbene intermediate, generated from a cationic gold catalyzed addition of N-oxides to alkynes. This method results in excellent chemical yields for a wide range of alkyne substrates and demonstrates good functional-group tolerance.

Supramolecular chemistry and self-assembly provide a valuable chance to understand the complicated topological structures on a molecular level. Two types of classical mechanically interlocked molecules, rotaxanes and catenanes, possess non-covalent mechanical bonds and have attracted more attention not only in supramolecular chemistry but also in the fields of materials science, nanotechnology and bioscience. In the past decades, the template-directed clipping reaction based on imine chemistry has become one of the most efficient methods for the construction of functionalized rotaxanes and catenanes. In this review, we outlined the main progress of rotaxanes and catenanes using the template-directed clipping approach of imine chemistry. The review contains the novel topological structures of rotaxanes and catenanes, functions and applications.

A convenient and efficient approach for the synthesis of 1-alkenylisoquinolines and 2-alkenylquinolines was developed via palladium-catalyzed coupling reactions between isoquinoline/quinoline N -oxides with olefins under external-oxidant-free conditions. Biological evaluation revealed that some of the obtained 1-alkenylisoquinolines exhibited in vitro antiproliferative activities on human-derived prostate, breast, esophageal, and stomach cancer cell lines.

A series of indolyl substituted 1,4,6,7-tetrahydropyrano[4,3-c]pyrazole derivatives were synthesized via a domino method based on the 1,4:3,6-Dianhydrofructose. The mechanism was proposed and proved by calculation with a density functional theory (DFT), which includes formation of phenylhydrazone, furanone ring opening, Fischer indole synthesis, pyrazole ring closing and a furan ring expansion. In vitro antitumor activity of all synthesized compounds against four human cancer cell lines (MCF-7, EC-109, HGC-27, and PC-3 cell lines) were then evaluated, using MTT assay. We found that most of the compounds were more potent than the positive control 5-fluorouracil. Particularly, compound 4i against HGC-27 and PC-3, 4j against EC-109 cell lines showed three fold greater activity than 5-fluorouracil, respectively. The activity of compounds 4c and 4d against MCF-7 cell line was close to that of doxorubicin.

Room-temperature phosphorescence (RTP) materials have attracted great attention due to their involvement of excited triplet states and comparatively long decay lifetimes. In this short review, recent progress on enhancement of RTP from purely organic materials is summarized. According to the mechanism of phosphorescence emission, two principles are discussed to construct efficient RTP materials: one is promoting intersystem crossing (ISC) efficiency by using aromatic carbonyl, heavy-atom, or/and heterocycle/heteroatom containing compounds; the other is suppressing intramolecular motion and intermolecular collision which can quench excited triplet states, including embedding phosphors into polymers and packing them tightly in crystals. With aforementioned strategies, RTP from purely organic materials was achieved both in fluid and rigid media.

An efficient, mild, metal-free, base-mediated intramolecular cyclization of N-alkyl, N-propargylic β-enaminones has been realized for the generation of polysubstituted pyrrole derivatives. This synthetic transformation tolerates a range of substituted N-alkyl, N-propargylic β-enaminones in moderate to good yields.

A copper-catalyzed coupling reaction of sulfonyl chlorides with tertiary amines via the oxidative C–N bond cleavage of tertiary amines was developed. Sulfonamides were synthesized using this strategy in moderate to good yields. The reaction was applicable to various tertiary amines, as well as sulfonyl chlorides.

Idelalisib ((S)-5-fluoro-3-phenyl-2-[1-(9H-purin-6-ylamino)-propyl]-3H-quinazolin -4-one, 9) is the first-in-class, highly selective inhibitor of phosphoinositide 3-kinase p110δ; it has been clinic...

A AgOAc catalyzed difunctionalization of activated alkenes through a difluoroamidic radical addition to afford difluoroamidated 3,3-disubstituted oxindoles has been developed. Various functional groups were well tolerated. Moreover, the product could be efficiently derived to the corresponding difluorofunctionalized alcohol, ketone, and ester in high yields. The mechanistic studies revealed that a radical pathway was involved in the transformation.

A de novo synthesis of a benzene ring allows for the preparation of a diverse range of heterocycles including indoles, benzofurans, benzothiophenes, carbazoles, and dibenzofurans from simple heteroaryl propargylic esters using a unified carbonylative benzannulation strategy. Multiple substituents can be easily introduced to the C4-C7 positions of indoles and related heterocycles.

A protocol for Pd-catalyzed intra- and intermolecular 2,5-alkoxyarylation reactions of furans to diastereospecifically synthesize two series of spirooxindoles is reported. This protocol likely involves an intramolecular dearomatizing Heck-type α-arylation of the furan ring to produce a cyclic allylic palladium and the subsequent intra- or intermolecular introduction of an alkyloxyl group at the other α-position of the ring, with different facial selectivities.

An efficient Fe(II)-catalyzed trifluoromethylation of vinylcyclopropanes was successfully developed. A series of CF3-containing dihydronaphthalene derivatives were prepared in moderate to high yields (up to 96%) under mild reaction conditions using the Togni reagent as the CF3 source.

A novel strategy for the difunctionalization of styrenes was developed. This synthesis includes the use of electrophilic perfluoroalkyl and tert-butylperoxy radicals and produces (1-(tert-butylperoxy)-2-perfluoroalkyl)ethylbenzene at room temperature, which has been traditionally difficult to synthesize. With at least four radical species included in the transformation, its high chemoselectivity was extraordinary; the results were further elucidated using computational studies. The methodology also holds a good potential for application as a result of its mild reaction conditions, ease of further modification, and insensitivity to moisture and air.

A ligand-free Cu-catalyzed [3 + 2] cycloaddition of ethyl 2-(quinolin-2-yl)acetates, ethyl 2-(isoquinolin-1-yl)acetates, and ethyl 2-(pyridin-2-yl)acetates with (E)-chalcones for a “one-pot” synthesis of pyrrolo[1,2-a]quinolines, pyrrolo[2,1-a]isoquinolines and indolizines has been developed. The annulation products were isolated in moderate to good yields with air as the sole oxidant under mild conditions.

Catalyzed by a rhodium complex of P-stereogenic diphosphine ligand trichickenfootphos (TCFP), asymmetric hydrogenation of racemic aldimines via dynamic kinetic resolution has been realized for the preparation of chiral arylglycines with good yields and enantioselectivities.

Reported herein is a bifunctional-organocatalyst-mediated enantioselective inverse-electron-demand 1,3-dipolar cycloaddition of C,N-cyclic azomethine imines with azlactones. The strategy provides concise access to enantioenriched C1-substituted tetrahydroisoquinolines featuring a pyrazolidinone scaffold. Moreover, the scalability and practical utility of this protocol was well demonstrated by employing a gram-scale reaction and some representative transformations.

Four new cyclopropane-based bisoxazolines were synthesized and applied to cobalt-catalyzed cross-coupling reactions between racemic α-bromo esters and aryl Grignard reagents. The reaction afforded a series of chiral α-arylalkanoic esters with high yields and good enantioselectivities (up to 93% yield, 92:8 er). This research focuses on the cross-coupling between racemic α-bromopropanoate and p-isobutylphenyl Grignard reagent’s which provides ibuprofen ester efficiently. Furthermore, ibuprofen ester 7e was transformed into (S)-ibuprofen (99:1 er) via hydrolysis and recrystallization.

The protocol enables smooth, rapid, and mild Negishi reactions to give the biaryls in excellent yields.

A potential ultraviolet (UV) nonlinear optical (NLO) material, K3B3O4(OH)4·2H2O, was successfully synthesized by hydrothermal methods. The compound crystallizes into the Cmc21 space group and exhibits isolated [B3O4(OH)4]3– anion groups connected by O–H···O hydrogen bonds. The UV–vis diffuse reflectance spectrum shows that K3B3O4(OH)4·2H2O has a wide transparency range with an absorption edge below 190 nm. Powder second harmonic generation (SHG) measurements using 1064 nm radiation revealed a moderate efficiency, 0.8 × KDP. Additional particle size vs SHG efficiency measurements indicate that K3B3O4(OH)4·2H2O is type I phase-matchable. Our calculated results show that the borate groups as well as the waters of hydration determine the NLO properties of K3B3O4(OH)4·2H2O.

The first catalytic enantioselective cross-coupling of a C(sp3)—H substrate with alkynes using molecular oxygen as the terminal oxidant is described.

Highly chemoselective Friedel–Crafts acylation with twisted amides under mild conditions is reported for the first time. The reaction shows high functional group tolerance, obviating the need for preformed sensitive organometallic reagents and expensive transition metal catalysts. The high reactivity of amides is switched on by ground-state steric distortion to disrupt the amide bond nN → πCO* resonance as a critical design feature. Conceptually, this new acid-promoted mechanism of twisted amides provides direct access to bench-stable acylating reagents under mild, metal-free conditions.

An efficient method for the synthesis of (Z)-selective α-trifluoromethyl alkenyl triflates is described. As an important fluorinated building block, it is utilized successfully for the synthesis of various trifluoromethyl derivatives such as diarylethylenes, enynes, alkynes, and benzofurans.

A Rh(III)-catalyzed coupling/cyclization cascade reaction is described, which involves arylimidates and diazo compounds and proceeds via intermolecular C–C bond formation and subsequent intramolecular C–N bond formation. Mechanistic investigation revealed that the reaction is a two-step process: the initial Rh(III)-catalyzed coupling/cyclization proceeds very fast and the following dehydration is rather slow. The reaction provides a direct approach to isoquinolines and isoquinolin-3-ols without any oxidants.

Two new quaternary thioarsenates(III) NaAg2AsS3·H2O (1) and KAg2AsS3 (2) with high yields have been successfully prepared through a facile surfactant-thermal method. It is interesting that 2 can only be obtained with the aid of ethanediamine (en), which indicates that weak basicity of solvent is beneficial to the growth of 2 compared with 1. Both 1 and 2 feature the similar two-dimensional (2D) layer structures. However, the distortion of the primary honeycomb-like nets in 2 is more severe than that of 1, which demonstrates that Na+ and K+ cations have different structure directing effects on these two thioarsenates(III). Both experimental and theoretical studies confirm 1 and 2 are semiconductors with band gaps in the visible region. Our success in preparing these two quaternary thioarsenates(III) proves that surfactant-thermal technique is a powerful yet facile synthetic method to explore new complex chalcogenides.

A nickel-catalyzed facile synthesis of structurally diverse five-membered lactams from aliphatic amides and terminal acetylenes with the assistance of an 8-aminoquinolyl auxiliary has been achieved. A broad range of terminal acetylenes and aliphatic amides proved to be the efficient coupling partners, furnishing the corresponding lactams in moderate to good yields. The transformation is proven to undergo an oxidative alkynylation followed by the intramolecular annulation process. The methodology can be extended to aromatic amides and acrylamides, which provides an efficient and straightforward protocol for the construction of a variety of isoindolinone and pyrrolidinone derivatives.

An efficient tandem copper(I)-catalyzed intramolecular allylic C(sp 3 )–H functionalization/C–N formation/oxidative reaction of 6-methyl-dihydropyrimidine-2-one-5-carboxamides has been developed for the synthesis of substituted 2 H -pyrrolo[3,4- d ]pyrimidine-2,5,7(3 H ,6 H )-trione derivatives in a single step in good to excellent yields.

Herein, we disclose the N-heterocyclic carbene (NHC)-catalyzed [3+3] annulation of challenging esters with methyl ketoimines for the highly enantioselective synthesis of intriguing δ-lactams featuring various substituent patterns. The annulation occurs under mild conditions and offers good tolerance, good yields and excellent enantioselectivities. The six-membered heterocyclic products are valuable for the synthesis of bioactive molecules.

An air-stable aryl substituted indenyl phosphine used in combination with Pd(OAc)2 provides a highly efficient catalyst for the Suzuki–Miyaura cross-coupling reaction of sterically hindered aryl halides with aryl boronic acids.

A simple and highly efficient protocol has been developed for the Pd/C-catalyzed ligand-free Suzuki–Miyaura reaction of potassium aryltrifluoroborates. In this catalytic system, the results demonstrate that oxygen plays a positive role in the cross-coupling reaction. In addition, this catalytic system could be successfully applied to synthesize biaryl compounds containing a carbazole moiety and the catalyst was recycled seven times without significant loss of catalytic activity.

Two new quaternary thioarsenates(III), SrAg4 As2 S6 ⋅2 H2 O (1) and BaAgAsS3 (2), have been prepared through a hydrazine-hydrothermal method at low temperature. Compound 1 possesses a two-dimensional (2D) layer network, while compound 2 features a one-dimensional (1D) column structure. The detailed structure analysis indicates that Sr(2+) and Ba(2+) cations have different directing effects on the structures of thioarsenates(III). Both experimental and theoretical studies demonstrate that compounds 1 and 2 are narrow-gap semiconductors. Our success in synthesizing these two quaternary thioarsenates(III) proves that the hydrazine-hydrothermal technique is a powerful yet facile synthetic method for exploring new complex chalcogenides with diverse crystal structures and interesting physical properties.

Synthetic macrocyclic receptors are the primary workhorses in supramolecular chemistry. In particular, macrocyclic arenes are versatile receptors due to their special binding performances and wide applications. In this Digest, we discussed the recent advances on naphthol-based macrocyclic receptors, with special emphasis on the construction of naphthol-based molecular receptors with high guest binding ability and selectivity, and broad guest binding scope.

An efficient, mild, and metal-free approach to direct diazenylation of N-heterocyclic compounds with aryltriazenes using Bronsted ionic liquid as a promoter has been developed for the first time. Many N-heterocyclic azo compounds were synthesized in good to excellent yields at room temperature under an open atmosphere. Notably, the promoter 1,3-bis(4-sulfobutyl)-1H-imidazol-3-ium hydrogen sulfate could be conveniently recycled and reused with the same efficacies for at least four cycles.

In searching for more bioactive compounds, phytochemical investigations on the acetone extract of the leaves of Nicotiana tabacum resulted in the isolation of two new sesquiterpenes, nicosesquiterpene A and B ( 1 and 2 ), along with four known sesquiterpene derivatives ( 3–6 ). Structural elucidation of 1 and 2 was performed by spectral methods, such as HRMS, IR, UV, 1D and 2D NMR spectroscopy. Compounds 1 and 2 are the first naturally occurring pterosin-type sesquiterpene bearing an isopropyl moiety. Compounds 1–6 were also evaluated for their anti-tobacco mosaic virus (anti-TMV) activity. The results showed that compounds 1 and 2 exhibited high anti-TMV activity with inhibition rates of 36.7% and 45.6%, respectively, which is higher than that of positive control. The other compounds also showed potential activity with inhibition rates in the range of 22.7%–29.2%.

Water-soluble 2N2O–Cu(II) complexes were synthesized and used for the catalytic oxidation of benzylic alcohols to the corresponding aldehydes in pure water resulting in high yields of up to 94%. Importantly, the catalytic system exhibits a wide substrate scope, high functional group tolerance and can be reused directly for subsequent reaction cycles. Using this catalytic system, the product 4-methylbenzaldehyde can be produced on a multi-gram scale and in the complete absence of any organic solvent, surfactant or phase transfer reagent. Copyright © 2016 John Wiley & Sons, Ltd.

A novel photoredox-mediated direct intermolecular C–H functionalization of N-methyl 5,6-dihydrobenzophenanthridine is developed utilizing the visible light-induced reductive quenching pathway of photocatalyst Ir(ppy)3. In the proposed coupling mechanism, an α-amino C-radical is generated at the 6-position of N-methyl 5,6-dihydrobenzophenanthridine which is capable of coupling with α-EWG (electron withdrawing group) substituted C-radicals. The utility of this methodology has been demonstrated via rapid access to the analogue of natural 6-substituted N-methyl 5,6-dihydrobenzophenanthridine alkaloids.

A base-catalyzed divergent reaction of 3-ylideneoxindoles with O-Boc hydroxycarbamates has been developed to provide efficient access to various amidoacrylates and spiroaziridine oxindoles with generally high yields, which should be potentially useful in drug discovery.