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Alkynes as unsaturated hydrocarbons have long been used for cyclization reactions. Various transition metal-catalyzed cyclizations of alkynes have been reported in the past decades. In this minireview, we mainly summarize the recent asymmetric cyclization of alkynes with other functional groups such as carbonyl-alkynes, cyano-alkynes, and enynes under the catalytic system of nickel and chiral ligands. [ABSTRACT FROM AUTHOR]

In recent years, with the development of organic synthetic chemistry, a variety of organic synthetic methods have been discovered and applied in practical production. Photochemistry and electrochemistry have been widely used in organic synthesis recently due to their advantages such as mild conditions and green and environmental protection and have now been developed into two of the most massive synthetic strategies in the field of organic synthesis. In order to further enhance the potential of photochemistry and electrochemistry and to overcome the limitations of each, organic synthetic chemists have worked to combine the two synthetic strategies together to develop photoelectrochemistry as a new synthetic method. Photoelectrochemistry achieves the complementary advantages and disadvantages of photochemistry and electrochemistry, avoids the problem of using stoichiometric oxidants or reductants in photochemistry and easy dimerization in electrochemistry, generates highly reactive reaction intermediates under mild conditions, and achieves reactions that are difficult to accomplish by single photochemistry or electrochemistry. This review summarizes the research progress in the field of photoelectrochemistry from the perspective of photoelectro-chemical catalysts in recent years, analyzes the catalytic mechanism of various catalysts in detail, and gives a brief outlook on the research direction and development prospects in this field. [ABSTRACT FROM AUTHOR]

Diverse, visible-light-induced transformations of methylenecyclopropanes (MCPs) have been reported in recent years, attracting significant attention from synthetic chemists. As readily accessible strained molecules, MCPs have sufficient reactivity to selectively generate different target products, through reactions with various radical species upon visible-light irradiation under regulated reaction conditions. These transformations can be classified into three subcategories of reaction pathway, forming ring-opened products, cyclopropane derivatives, and alkynes. These products include pharmaceutical intermediates and polycyclic/heterocyclic compounds that are challenging to obtain using traditional methods. This review summarizes the recent advancements in this field. [ABSTRACT FROM AUTHOR]

CO2 as a classical C1 unit is often used in the synthesis of high value-added carboxylic acids and their derivatives in organic synthetic chemistry. There have been many reports in the past on electrochemically mediated chemical transformations utilizing electrons as redox reagents. This review will focus on electrocarboxylation methods in the recent 5 years, including metal-mediated electrocarboxylation, direct electrocarboxylation, and some novel electrocarboxylation methods. [ABSTRACT FROM AUTHOR]

The development of metal–organic framework (MOF)-based fluorescent sensors in the detection of metal ions has attracted significant interest. In this study, a novel 2D MOF Tb-DBA was constructed using Tb3+ and 2′-amino-1,1′:4,1′′-terphenyl-4,4′′-dicarboxylic acid (H2DBA) by a solvothermal method. Tb-DBA could detect Al3+, Cr3+ and Fe3+ ions rapidly, sensitively, selectively and reversibly. The detection limit is as low as the nM level. Tb-DBA displayed fluorescence enhancement in the presence of Al3+, Cr3+ and Fe3+ ions. Significantly, Al3+, Cr3+ and Fe3+ ions could be visually detected under UV light. Additionally, Tb-DBA could also act as an indicator for alkaline solutions when pH > 10. The detection mechanism was studied by ICP, EDS and PXRD tests. These studies illustrated that cation exchange proceeded between Tb-DBA and Al3+, Cr3+ and Fe3+ ions, which inhibited the energy transfer from DBA to Tb3+ and enhanced the π*–π transitions of DBA. [ABSTRACT FROM AUTHOR]

A novel palladium-catalyzed oxidative cyclization of aniline-tethered alkylidenecyclopropanes using molecular oxygen as the terminal oxidant through β-carbon elimination of aminopalladation intermediates is disclosed. The reaction opens up an effective way to obtain a series of 2- and 3-vinylindoles which are important synthetic intermediates in many natural indole derivatives. [ABSTRACT FROM AUTHOR]

Novel Ag@C nanocables are successfully synthesized through a hydrothermal self-assembly process, and employed as the support material to fabricate a uniformly distributed Pt nanoparticle electrocatalyst (Pt/Ag@C) for glycerol oxidation reaction (GOR). Electrochemical measurements demonstrate that this Pt/Ag@C catalyst can have both superior electrocatalytic GOR activity and stability, confirming that the Ag@C nanocables should be a great material for supporting the catalyst. Theoretical calculations are also carried out for fundamental understanding of the enhanced catalytic performance of this Pt/Ag@C catalyst. The results show that this Pt/Ag@C catalyst should be a great candidate as the anode catalyst for direct glycerol fuel cells. [ABSTRACT FROM AUTHOR]

Carbon dioxide as a classic C1 source has long been investigated in organic synthetic chemistry. Diverse catalytic methods for CO2 activation have been reported over the past several decades. In this minireview, we mainly focus on detailing recent advances (since 2020) in utilizing carbon dioxide to attain the carboxylation of organic motifs via photoredox and metallaphotoredox catalysis. [ABSTRACT FROM AUTHOR]

A sustainable C(sp2)–C(sp3) cross-electrophile coupling was developed between readily available 5-bromophthalide and 1-benzyl-4-iodopiperidine under micellar conditions, leading to a key intermediate of one of our development compounds. Copper was found to play a crucial role as a co-catalyst in this dual catalysis system. The chemistry and process were successfully demonstrated in a kilo scale to deliver sufficient drug substance to the clinical campaigns. This is the first reported scale-up of such a challenging cross-electrophilic coupling that uses an aqueous medium, and not undesirable reprotoxic polar aprotic solvents (e.g. DMF, DMAc, and NMP). [ABSTRACT FROM AUTHOR]

An interesting type of reaction involving functionalized methylenecyclopropanes (MCPs) has been revealed. Here, a nucleophilic attack of an anionic species onto a partially polarity-reversed MCP was realized by treating a neighbouring carboxylic ester tethered to the MCP and amine with KHMDS to realize an umpolung ring opening of the MCP. This work established an operationally convenient protocol for the rapid construction of isoquinolinone frameworks. [ABSTRACT FROM AUTHOR]

The tandem Pauson–Khand type reactions of 1,4-enynes tethered by a cyclopropyl group with two molecules of CO proceed smoothly in the presence of [Rh(CO)2Cl]2 under a CO atmosphere to give the corresponding 6-hydroxy-2,3-dihydro-1H-inden-1-one derivatives in moderate yields under mild conditions. [ABSTRACT FROM AUTHOR]

A palladium-catalyzed divergent synthesis of spirooxindoles fused with a five- or a six-membered ring by a cycloaddition reaction of vinylidenecyclopropane-diesters with methyleneindolinones was disclosed. This protocol features an in situ generated unprecedented zwitterionic π-propargyl palladium species in cycloaddition reactions and a switchable process between (3+2) and (4+2) cycloadditions by changing the phosphine ligand. [ABSTRACT FROM AUTHOR]

A silver-catalyzed diastereoselective one-pot domino cyclization-migration/inverse electron-demand oxo-Diels–Alder reaction has been disclosed in this communication through the in situ generated cyclobutane-fused furan intermediate with 4-vinyl-2,3-dioxopyrrolidine for the construction of 2-oxopyrrolidine-fused tricyclic compounds in moderate to good yields with a broad substrate scope under mild conditions. This new synthetic protocol features good efficiency and atom- and step-economy. A plausible reaction mechanism has also been proposed on the basis of previous reports, NMR tracing and control experiments. [ABSTRACT FROM AUTHOR]

The transformations of cyclopropenes have attracted the attention of organic chemists for decades. As readily accessible strained carbocycles, cyclopropenes show a diverse range of reactivities. This feature article focuses on the developments of cyclopropenes from 2016 until the end of 2019, including reactions through vinylmetal carbenes, reactions through metal complex insertion, addition reactions with 1,3-dipole, radical reactions of cyclopropenes, and reactions of highly reactive in situ generated cyclopropenes. In addition, several new synthetic methods and applications of cyclopropenes are also disclosed in this paper. [ABSTRACT FROM AUTHOR]

A gold-catalyzed cascade cyclization of O-tethered 1,7-enynes bearing a cyclopropane moiety has been reported in this communication, affording multi-substituted furans in moderate to good yields. The reaction proceeded through an intramolecular O-nucleophilic addition and 3,3-sigmatropic rearrangement followed by ring-opening of the cyclopropane unit along with the further reaction with electrophiles. The C–C bond cleavage of a strained cyclopropane moiety in the presence of a gold catalyst and the aromatization provided the driving force for this cascade cyclization. The practical transformations of the obtained diiodinated furan have also been indicated. [ABSTRACT FROM AUTHOR]

We herein report a rhodium(iii)-catalyzed cross coupling of indole derivatives with alkylidenecyclopropanes (ACPs) in the presence of KCl, affording the alkene products exclusively with E-selectivity via C–H bond activation. The beta-H elimination to afford the conjugated diene derivatives has been suppressed by the addition of KCl. A plausible reaction mechanism has been proposed along with derivatization of the obtained product to demonstrate the practical usefulness of this synthetic protocol. [ABSTRACT FROM AUTHOR]

A gold(i)-catalyzed highly efficient kinetic resolution of indole–allene derivatives has been demonstrated, providing enantiomerically enriched polycyclic indolines possessing four stereogenic centers including an all-carbon quaternary center in a spirocyclic framework and β-substituted tryptamine derivatives in good to excellent ee values and high s selectivities with good functional group tolerance under mild conditions in an atom-economical way. [ABSTRACT FROM AUTHOR]

A palladium(0)-catalyzed intramolecular transfer hydrogenation and cycloaddition of p-quinamine-tethered alkylidenecyclopropanes (ACPs) to synthesize perhydroindole scaffolds has been reported in this communication. Mechanistic investigations on the basis of deuterium labeling experiments suggest that the reaction proceeded through an oxidative addition of Pd(0) into the distal bond of the ACP moiety to afford a trimethylenemethane (TMM)–Pd intermediate followed by transfer hydrogenation using alcohol. [ABSTRACT FROM AUTHOR]

Metal-free and environmentally friendly synthesis highly controlled by natural sources like visible light and air (or oxygen) is always a pursuit of green chemistry. In this paper, an atmosphere and light tuned highly diastereoselective synthesis of two important polyheterocyclic skeletons: cyclobuta/penta[b]indoles from aniline-tethered alkylidenecyclopropanes with alkynes, has been developed. The chiral cyclobuta/penta[b]indoles have also been obtained by optical resolution. [ABSTRACT FROM AUTHOR]

A novel gold(i)-catalyzed intramolecular tandem cyclization reaction of ortho-(arylethynyl)arenemethylenecyclopropanes provided an efficient approach to prepare functionalized 11H-benzo[a]fluorene derivatives in moderate to good yields. Further transformations as well as applications of the products have been presented and a plausible reaction mechanism has also been proposed on the basis of deuterium labeling and control experiments. [ABSTRACT FROM AUTHOR]

A set of reactions involving copper-catalyzed trifluoromethylazidation and then rearrangement of aniline-linked 1,7-enynes with the relatively poorly reactive Togni reagent I and TMSN3 was developed, and provided facile access to structurally diverse and useful CF3-substituted azaspirocyclic dihydroquinolin-2-ones bearing two adjacent quaternary carbon centers. We were also able to obtain these products on a large scale. Moreover, the obtained products were further transformed into a range of synthetically valuable furoindolines bearing three consecutive quaternary carbon centers after reduction by NaBH4. Also, the delivery of multi-functionalized aziridines as a result of alcoholysis and LiAlH4-reduction of corresponding dihydroquinolin-2-ones 2ba demonstrated the synthetic value of this newly developed protocol. [ABSTRACT FROM AUTHOR]

Copper-catalyzed cascade cyclization of 1,5-enynes with two types of hypervalent reagents was developed via consecutive trifluoromethylazidation/diazidation and intramolecular click reaction (CUAAC), providing one-pot self-assembly of triazole fused isoindolines bearing a trifluoromethyl or an azide moiety. Moreover, the construction of a trifluoromethylcyclopropyl unit, which has been considered as a metabolically stable replacement for a tert-butyl moiety and was difficult to access, was also achieved under trifluoromethylazidation conditions. All these reactions exhibited excellent chemoselectivity, good to excellent yields and broad functional group tolerance. [ABSTRACT FROM AUTHOR]

A new method for the synthesis of azaaromatic vinylcyclopropanes (VCPs) has been disclosed in this paper by using pyrrole or indole derivatives as nucleophilic reagents to react with vinylidenecyclopropane-diesters (VDCP-diesters) in the presence of a Pd catalyst, a phosphine ligand and a base under mild conditions in up to 98% yield with a reasonable substrate scope. This reaction is one of the few examples of hydroamination at electron-rich allene's β-position. A plausible reaction mechanism has also been proposed through a zwitterionic π-propargyl N-palladium species according to the previous work and the obtained deuterium labeling experimental result. [ABSTRACT FROM AUTHOR]

The site selective C(sp2)–H bond functionalization of olefins has been achieved through a visible-light-induced photoredox-quinuclidine dual catalysis upon merging the quinuclidinium radical cation addition to alkene strategy and the distal heteroaryl ipso-migration strategy. This synthetic protocol features a simple operation with readily available starting materials in good step-economy to access alkenylheteroaromatic products in moderate to good yields under mild conditions. A plausible cascade catalytic reaction mechanism is also proposed. [ABSTRACT FROM AUTHOR]

Novel intramolecular cycloisomerizations of nitrogen-tethered cyclopropenes with indole in the presence of Brønsted acids have been developed. The reactions proceeded through the same pathway but stopped at different stages according to different substituent styles, affording azocino[5,4-b]indole 2 and (epiminoethano)cyclopenta[b]indole 4 in moderate to good yields. [ABSTRACT FROM AUTHOR]

A Cu-catalyzed regio- and enantioselective aminoboration of alkylidenecyclopropanes (ACPs) with bis(pinacolato)-diboron (B2pin2) and hydroxylamines has been described in this paper, affording the corresponding cyclopropane-containing β-aminoalkylboranes in good yields under mild conditions. Moreover, a catalytic asymmetric variant of this transformation has also been realized by using a copper complex with a (S)-BINAP ligand along with further transformation of the product to give cyclopropane-containing 1,2-aminoalcohols. [ABSTRACT FROM AUTHOR]

Azide-methylenecyclopropanes (azide-MCPs) underwent an intermolecular cyclization with isonitriles catalyzed by a RhII complex to produce a series of pyrrolo[2,3-b]quinolines in moderate to good yields via carbodiimide intermediates. Moreover, synthetic applications of these products to construct structurally novel and useful heterocycles have also been achieved. [ABSTRACT FROM AUTHOR]

The synthesis of medium-sized heterocycles possessing a trans double bond is still a challenge. Herein, gold(i)-catalyzed 1,2-acyloxy migration/intramolecular cyclopropanation/ring enlargement cascade reaction of furans has been developed, providing highly efficient access to ten- and eleven-membered heterocycles with a broad substrate scope under mild reaction conditions. The reaction outcome features high chemoselectivity at the C5-position of furan. Moreover, a trans-double bond was embodied in the medium ring system. [ABSTRACT FROM AUTHOR]

A ring-opening/cyclization cascade reaction of α-brominated amide-tethered alkylidenecyclopropanes in the presence of photocatalyst 4CzIPN under visible-light irradiation was developed to afford polycyclic benzazepine derivatives in good yields with broad substrate scope and good functional tolerance. A plausible mechanism involving a halogen atom transfer (XAT) process and a radical chain process is proposed for this reaction. This study provides a concise and practical strategy for the synthesis of benzazepine derivatives. [ABSTRACT FROM AUTHOR]

The kinetics of the reactions of tributylphosphine with allenic and olefinic Michael acceptors in dichloromethane at 20 °C was followed by photometric and NMR spectroscopic methods. Combination with DFT-calculated methyl anion affinities revealed the relevance of retroaddition barriers in phosphine-catalysed reactions when mixtures of allenic and olefinic substrates are used. [ABSTRACT FROM AUTHOR]

A novel Rh(ii) catalyzed intramolecular 1,2-sulfur rearrangement/intermolecular aza-Diels–Alder cascade initiated by azavinyl carbenes has been developed, efficiently affording sulfur-containing tetrahydropyridine derivatives or α,β-unsaturated imines with a broad substrate scope. [ABSTRACT FROM AUTHOR]

This critical review discusses recent developments in the field of cyclopropene chemistry. Although several excellent reviews that mainly focused on the thermolysis and pyrolysis as well as metal-mediated reactions of cyclopropenes have been published, significant new developments have also been achieved in recent years. This brand new review provides an overview of the progress from 2007 to 2011 on the syntheses and transformations of cyclopropenes as well as their related mechanistic studies (238 references). [ABSTRACT FROM AUTHOR]

The PdCl2-promoted reactions of methylenecyclopropanes (MCPs) 1bearing diaryl substituents on the terminal double bond were carefully investigated. The solvents employed significantly affected the reaction outcomes. It was found that dimeric allylpalladium(ii) complexes 2a–2fcan be obtained as the sole products in acceptable to good yields under mild reaction conditions with THF as the solvent, while dimeric allylpalladium(ii) complexes 2a–2falong with another type of dimeric allylpalladium(ii) complexes 4a–4ecan be obtained in good to high total yields if N,N-dimethylacetamide (DMAc) was used as the solvent. Moreover, using N,N-dimethylformamide (DMF) as the solvent in the presence of water, it was found that water can also participate in the reaction to form another type of dimeric allylpalladium(ii) complex 6as the minor product. All of these dimeric allylpalladium(ii) complexes reported in the paper have been characterized by X-ray crystal structure diffraction. [ABSTRACT FROM AUTHOR]

A novel Pd/Au vinylene complex synthesized through cyclization of σ,π-heterodinuclear (Pd/Au) acetylide reacted with iodobenzene to give a Pd vinyl species, where the presence of a strong metallophilic Pd⋯Au interaction was found to facilitate phenyl transmetalation from Pd to Au, followed by reductive elimination at Au. [ABSTRACT FROM AUTHOR]

A catalyst-free intramolecular geminal aminofluorination of ortho-sulfonamide-tethered alkylidenecyclopropanes has been developed. The reaction proceeded through two SET processes with Selectfluor to give a fluorinated cyclopropylcarbinyl cation and a further Wagner-Meerwein rearrangement to generate a cyclobutyl carbocation, which undergoes intramolecular nucleophilic capture by amide to forge fluorinated cyclobuta[b]indoline derivatives. A polycyclic multi-fluorinated byproduct was also formed through a Ritter-type reaction in some cases. [ABSTRACT FROM AUTHOR]

We have developed the regiospecific and stereoselective synthesis of (E)- and (Z)-2-phosphino-1-alkenyl boronates via Cu-catalyzed hydroboration of alkynylphosphines. A remarkable ligand-controlled stereoselectivity in the transformation is presented. The study on the coordination chemistry of the new phosphine/borane compounds with gold suggests the presence of very weak Au → B interaction in the gold complex 4 ligated by (E)-2-phosphino-1-alkenyl boronate 2a. [ABSTRACT FROM AUTHOR]

Homo (Au3)- and heterotrinuclear coinage metal complexes (Au2Ag and Au2Cu) ligated by the first tritopic carbanionic N-heterocyclic carbene (NHC) have been prepared by deprotonation of ditopic NHC digold complexes and structurally characterized by single-crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

A gold-catalyzed method for the construction of indolizines with eight-membered rings has been developed. The reaction proceeded through a two-fold hydroarylation with indole or pyrrole derivatives containing a 1,6-diyne using a tri(1-adamantyl)phosphine gold complex as the catalyst, affording 1,8-disubstituted indolizines in moderate to good yields in DCE at 80 °C. The potential usefulness of these indolizines as blue or green OLEDs has been also disclosed. [ABSTRACT FROM AUTHOR]

A catalytic domino amination and oxidative coupling of in situ prepared gold acetylides has been developed for the synthesis of abnormal NHC (aNHC) gold complexes, and key vinylene digold intermediates are isolated and structurally characterized. [ABSTRACT FROM AUTHOR]

During the past several years, functionalized alkylidenecyclopropanes (FACPs) have attracted intensive attention in synthetic chemistry. Many interesting transformations of FACPs have been developed to synthesize a lot of structurally diverse and valuable polycyclic and heterocyclic compounds. This review will classify FACPs into aryl-FACPs, alkyl-FACPs and ring-FACPs for the first time, and recent interesting chemical transformations in these research fields will be included, respectively, from 2011. Moreover, we will pay more attention to the clarification of the reaction mechanism, in which the C–C bond cleavage of alkylidenecyclopropanes (ACPs) will be emphasized. [ABSTRACT FROM AUTHOR]

A Pt(ii)-catalyzed cyclization of (hetero)aryl-allenes has been developed, providing controllable synthesis of substituted 2,3-dihydropyrroles and polyheterocyclic skeletons. Another notable feature of this method is the dual-role of the Pt(ii) catalyst: initiation of the migration of the (hetero)arylmethylene group and the subsequent Friedel–Crafts type annulation. [ABSTRACT FROM AUTHOR]

We have developed a facile method for the synthesis of novel five- and six-membered cyclic formamidinium salts bearing an unsaturated backbone through Cu(ii)- or Ag(i)-catalyzed amination of N-alkynyl formamidines. Cu(ii)- or Ag(i)-promoted cyclization in a stoichiometric mode was also investigated, and it could offer some desirable cyclic formamidinium salts, which cannot be prepared through a catalytic reaction mode. Two rhodium(i) complexes were prepared through the treatment of [Rh(cod)Cl]2 with the free carbenes obtained in situ by the deprotonation of the corresponding resulting formamidinium salts. [ABSTRACT FROM AUTHOR]

We have investigated the ligand effect on the gold-activated intramolecular amidiniumation of formamidine having a terminal alkyne, and observed the transformation of vinyl gold species into a gem-digold intermediate comprising two C–Au σ bonds, which represents a new binding mode for gem-digold species in the gold-promoted transformation of alkynes. [ABSTRACT FROM AUTHOR]

Single Co adatoms adsorbed on a double-layer NaCl film supported by Cu(111) were negatively charged after applying a positive voltage pulse to the sample in a scanning tunnelling microscope. Density functional calculations showed that the magnetic moment of Co changed from 3μB to 2.2μB after charge state manipulation. [ABSTRACT FROM AUTHOR]

The gold(i)-catalyzed dehydrogenative cycloisomerization of cyclopropane-tethered 1,5-enynes proceeded smoothly to give multisubstituted benzene derivatives in good to excellent yields. Synthetically important benzocyclobutenes can be produced in high yields in the presence of a gold(i) catalyst and DDQ. Furthermore, this reaction also works very well for non-cyclopropane tethered 1,5-enynes. [ABSTRACT FROM AUTHOR]

Air-unstable magnetic aluminum phthalocyanine (AlPc) molecules are prepared by an on-surface metalation reaction of phthalocyanine with aluminum (Al) atoms on Au(111) in ultrahigh vacuum. Experiments and density functional theory calculations show that an unpaired spin is located on the conjugated isoindole lobes of the molecule rather than at the Al position. [ABSTRACT FROM AUTHOR]

Solvothermal reactions of Cd(OAc)2/Zn(OAc)2 with a new ligand, (pyridin-3-yl)methyl 4-(2-(4-((pyridin-3-yl)methoxy)phenyl)diazenyl)benzoate (L1), under different templates via an in situ ligand transformation reaction produced five coordination polymers, [CdL2(H2O)]n (1), [Cd1.5L3]n (2), [Cd2L4]n (3), [(ZnL2)·H2O]n (4) and {[Zn(1,3-BDC)(L1)]·MeCN·0.5H2O}n (5), where HL = 4-(2-(4-((pyridin-3-yl)methoxy)phenyl)diazenyl)benzoic acid, 1,3-H2BDC = 1,3-benzenedicarboxylic acid. Compound 1 is a three-dimensional (3D) wave-like structure constructed from 4-connected Cd(ii) nodes and L− linkers. Compounds 2 and 3 bear similar 2D networks built from metallocyclic [Cd4L4] units. Compound 4 features a wrinkled 2D layer based on metallocyclic [Zn4L4] units. Compound 5 has a novel 1D single-wall metal–organic nanotube (SWMONT) in which the 1,3-BDC ligands act as linkers to connect the [Zn2(L1)2] rings. The results reveal that the different templates have a significant effect on the final structures. Compounds 1–5 exhibited relatively high photocatalytic activity towards the degradation of methylene blue (MB) in aqueous solution under UV-Vis irradiation. The kinetics of the catalytic photodegradation reactions and the stabilities of photocatalysts were also investigated. [ABSTRACT FROM AUTHOR]

An effective synthetic protocol for structurally diverse 4-acyloxy-1,2-dihydroquinoline compounds has been accomplished by a gold(i)-catalyzed tandem [3,3]-rearrangement and intramolecular hydroamination of propargylic esters, affording the desired products in good yields. Moreover, the asymmetric variant of this cyclization has also been achieved using a chiral nitrogen acyclic carbene (NAC) gold(i) complex. These products have application in the enantioselective synthesis of an aromatase inhibitor within three simple steps. [ABSTRACT FROM AUTHOR]

The unprecedented palladium-catalyzed cascade cyclization of allylamine-tethered alkylidenecyclopropanes with an ethyl difluoroiodoacetate or perfluoroalkylated reagent is developed, providing facile access to a variety of synthetically and medicinally valuable iodine/difluoromethylene- and perfluoroalkyl-containing 1-benzazepine frameworks. These reactions exhibited good yields and functional group tolerance via a radical mechanism. [ABSTRACT FROM AUTHOR]

We have developed a facile synthetic method to access furoquinoline and thienoquinoline derivatives via a thermally induced ring-opening and cyclization reaction from ortho-aminoaryl-tethered alkylidenecyclopropanes with the in situ generation of isocyanates or isothiocyanates. These reactions exhibited excellent yields and functional group tolerance under metal-free conditions. [ABSTRACT FROM AUTHOR]