Copper-catalysed photoinduced decarboxylative alkynylation: a combined experimental and computational study
作者:Yu Mao、Wenxuan Zhao、Shuo Lu、Lei Yu、Yi Wang、Yong Liang、Shengyang Ni、Yi Pan
DOI:10.1039/d0sc02213f
日期:——
Redox-active esters (RAEs) as alkyl radical precursors have demonstrated great advantages for C–C bond formation. A decarboxylative cross-coupling method is described to afford substituted alkynes from various carboxylic acids using copper catalysts CuCl and Cu(acac)2. The photoexcitation of copper acetylides with electron-rich NEt3 as a ligand provides a general strategy to generate a range of alkyl
Copper-Catalyzed Radical Bis(trifluoromethylation) of Alkynes and 1,3-Enynes
作者:Haigen Shen、Hawen Xiao、Lin Zhu、Chaozhong Li
DOI:10.1055/s-0039-1690187
日期:2020.1
The copper-catalyzed radical bis(trifluoromethylation) of alkynes and 1,3-enynes is described. With Cu(CH3CN)4BF4 as the catalyst, the reaction of arylalkynes with Togni reagent II and (bpy)Zn(CF3)2at roomtemperature affords the corresponding 1,2-bis(trifluoromethylated) alkenes in good yields with excellent E-stereoselectivity. Under similar conditions, the reaction of 1,3-enynes provides the corresponding
Palladium-Catalyzed Methylation of Aryl, Heteroaryl, and Vinyl Boronate Esters
作者:Alexander M. Haydl、John F. Hartwig
DOI:10.1021/acs.orglett.9b00025
日期:2019.3.1
method for the direct methylation of aryl, heteroaryl, and vinyl boronate esters is reported, involving the reaction of iodomethane with aryl-, heteroaryl-, and vinylboronate esters catalyzed by palladium and PtBu2Me. This transformation occurs with a remarkably broad scope and is suitable for late-stage derivatization of biologically active compounds via the boronate esters. The unique capabilities
Direct Synthesis of α-Trifluoromethyl Ketone from (Hetero)arylacetylene: Design, Intermediate Trapping, and Mechanistic Investigations
作者:Arun Maji、Avijit Hazra、Debabrata Maiti
DOI:10.1021/ol502071g
日期:2014.9.5
Regioselective addition across the alkynes has been achieved in a silver-catalyzed protocol utilizing Langlois reagent (CF3SO2Na) and molecular O2 to access medicinally active α-trifluoromethyl ketone compounds. This method was successful in producing α-trifluoromethyl ketone in heterocyclic scaffolds, which are incompatible with earlier strategies. Experimental findings suggest a mechanism involving α-styrenyl radical intermediate and 1-methyl-2-pyrrolidinone (NMP) solvent, which leads to crystallographically characterized N-methylsuccinimide. Isotope labeling, kinetic studies, and intermediate trapping further helped to gain insight into this energy-demanding process.