Synthesis of β‑Difluoroalkylated Acrylonitriles in the Presence of Copper Powder

A highly regio- and stereoselective copper-mediated cyanodifluoro­alkylation of alkynes with ethyl difluoroiodoacetate and trimethylsilyl cyanide (TMSCN) is described. The three-component coupling reaction provides straightforward access to a variety of useful difluoroalkyl-substituted acrylonitriles. The introduction of the nitrile unit is of great importance in drug discovery for the modification of this fragment. Preliminary mechanistic investigations indicate that a vinyl iodide intermediate and a difluoroalkyl radical might be involved in this transformation

Palladium-Catalyzed Radical Cascade Iododifluoromethylation/Cyclization of 1,6-Enynes with Ethyl Difluoroiodoacetate

A novel and convenient Pd-catalyzed radical cascade iododifluoromethylation/cyclization of 1,6-enynes with ethyl difluoroiodoacetate is demonstrated. The proposed transformation presents high stereoselectivity under mild and facile reaction conditions, thereby allowing an efficient access to a variety of iodine-containing difluoromethylated pyrrolidines. A possible radical pathway for the transformation is proposed on the basis of the results of control experiments and relevant literature reviews

Palladium-Catalyzed Intermolecular Aryldifluoroalkylation of Alkynes

A palladium-catalyzed aryldifluoroalkylation of alkynes with ethyl difluoroiodoacetate and arylboronic acids as reaction partners is described. The alkyne difunctionalization process provides various aryldifluoroalkylated products in one pot under mild reaction conditions. A wide range of alkynes and diverse arylboronic acids are compatible with these reaction conditions. High reaction efficiency and broad substrate scope are the notable features of this transformation. Preliminary mechanistic investigations indicate that a difluoroalkyl radical addition pathway is involved in this transformation

Silver-Catalyzed Oxidative Cyclization of Propargylamide-Substituted Indoles: Synthesis of Phosphorated Indoloazepinones Derivatives

A silver-catalyzed oxidative cyclization of 2- or 3-propargylamide-substituted indoles to synthesize phosphorated indoloaze­pinone derivatives is described. This reaction displays a difunctionalizalion of alkynes with diphenyl­phosphine oxides to construct a seven-membered ring through a radical cyclization process. The indolo­azepinones derivatives are common structural motifs found in many natural products and pharmaceuticals

Copper-Catalyzed Intermolecular Cyanotrifluoromethylation of Alkenes

A novel and highly practical reaction for the copper-catalyzed intermolecular cyanotrifluoromethylation of alkenes is presented here. This methodology provides a general and straightforward way to synthesize a variety of useful CF₃-containing nitriles, which can be used for further preparation of pharmaceutically and agrochemically important compounds in synthetic organic chemistry

Copper-Catalyzed Three-Component Cyano­trifluoro­methyla­tion/Azido­trifluoro­methyla­tion and Carbo­cycli­zation of 1,6-Enynes

A novel three-component strategy for the cyano­trifluoro­methyla­tion/azido­trifluoro­methyla­tion and carbocyclization of 1,6-enynes is developed. The reaction proceeds smoothly under a moderate temperature by using a copper catalyst, which provides a rapid and concise access to addition–carbocyclization products. Furthermore, the products obtained can be useful building blocks in discoveries of lead compounds and other biologically active CF₃-containing heterocycles

Copper-Catalyzed Intermolecular Cyanotrifluoromethylation of Alkenes

A novel and highly practical reaction for the copper-catalyzed intermolecular cyanotrifluoromethylation of alkenes is presented here. This methodology provides a general and straightforward way to synthesize a variety of useful CF₃-containing nitriles, which can be used for further preparation of pharmaceutically and agrochemically important compounds in synthetic organic chemistry

Palladium-Catalyzed Regioselective Difluoroalkylation and Carbonylation of Alkynes

A novel, four-component synthetic strategy to synthesize a series of β<i>-</i>difluoroalkyl unsaturated esters/amides with high regioslectivity is described. This Pd-catalyzed difluoroalkylation and carbonylation reaction can be carried out with simple starting materials. Through this protocol, two new C–C bonds (including one C–CF₂ bond) and one C–O­(N) bond are constructed simultaneously in a single step. The synthetic utility of this reaction system has been certified by the applicability to a wide scope of alkynes and nucleophiles. Preliminary mechanistic studies suggest that the difluoroalkyl radical pathway is involved in this reaction

Silver-Promoted Oxidative Cyclization of 1,6-Enynes: Highly Regioselective Synthesis of Phosphorated Fluorene Derivatives

A silver-promoted oxidative cyclization of 1,6-enynes with disubstituted phosphine oxides is developed for the synthesis of fluorene derivatives. The reaction proceeds with high regioselectivity by constructing one C–P bond and two C–C bonds in one step. Moreover, reduction of the pentavalent phosphine enlarges the application scope of the product

Silver-Promoted Oxidative Cyclization of 1,6-Enynes: Highly Regioselective Synthesis of Phosphorated Fluorene Derivatives

A silver-promoted oxidative cyclization of 1,6-enynes with disubstituted phosphine oxides is developed for the synthesis of fluorene derivatives. The reaction proceeds with high regioselectivity by constructing one C–P bond and two C–C bonds in one step. Moreover, reduction of the pentavalent phosphine enlarges the application scope of the product