Silver-Promoted Radical Cascade Aryldifluoromethylation/Cyclization of 2-Allyloxybenzaldehydes for the Synthesis of 3-Aryldifluoromethyl-Containing Chroman-4-one Derivatives
Ag(i)-catalyzed oxidative decarboxylative gem-difluoromethylenation of difluoroacetates with isonitriles has been developed for the formation of C–CF2 bonds.
Visible Light-Promoted Phosphine-Catalyzed Difluoroalkylation of Arenes and Heterocycles
作者:Heng Lu、Dong-yu Wang、Ao Zhang
DOI:10.1021/acs.joc.9b02882
日期:2020.1.17
A visible light-promoted difluoroalkylation reaction of arenes or heterocycles, using triaryl phosphine as the catalyst and difluoroalkyl iodide as the alkylating agent, is presented. The strategy is highlighted by photocatalyst-free, mild reaction conditions and a broad substrate scope. Mechanistic experiments indicate that this reaction involves a radical-chain process that is initiated by an electron
The first AgI-mediated C–H ethoxycarbonyl difluoromethylation with TMSCF2COOEt (TMS = trimethylsilyl) has been developed. The radical difluoromethylation proceeds smoothly to give the difluoromethylated arenes in moderate to high yields with Friedel–Crafts-type regioselectivity. Mechanistic studies indicate that the innate C–H difluoromethylation proceeds through an electrophilic radical-type pathway
An efficient silver-catalyzed method of decarboxylative radical allylation of α,α-difluoroarylacetic acids to build CF2–allyl bonds has been developed. Using allylsulfone as an allyl donor, α,α-difluorine substituted arylacetic acids bearing various functional groups are successfully allylated to access a series of 3-(α,α-difluorobenzyl)-1-propylene compounds in moderate to excellent yields in aqueous
Catalytic Decarboxylative Fluorination for the Synthesis of Tri- and Difluoromethyl Arenes
作者:Satoshi Mizuta、Ida S. R. Stenhagen、Miriam O’Duill、Jamie Wolstenhulme、Anna K. Kirjavainen、Sarita J. Forsback、Matthew Tredwell、Graham Sandford、Peter R. Moore、Mickael Huiban、Sajinder K. Luthra、Jan Passchier、Olof Solin、Véronique Gouverneur
DOI:10.1021/ol4009377
日期:2013.6.7
Treatment of readily available alpha,alpha-difluoro- and alpha-fluoroarylacetic acids with Selecffluor under Ag(I) catalysis led to decarboxylative fluorination. This operationally simple reaction gave access to tri- and difluoromethylarenes applying a late-stage fluorination strategy. Translation to [F-18]labeling is demonstrated using [F-18]Selectfluor bis(triflate), a reagent affording [F-18]tri- and [F-18]difluoromethylarenes not within reach with [F-18]F-2.