Aqueous Base Promoted O-Difluoromethylation of Carboxylic Acids with TMSCF2Br: Bench-Top Access to Difluoromethyl Esters
摘要:
A method for the O-difluoromethylation of carboxylic acids using commercially available TMSCF2Br is disclosed. The devised benchtop reaction system is air-stable and offers mild reaction conditions while using readily available reagents and solvents. The method is applicable to both aliphatic and aromatic carboxylic acids while demonstrating compatibility with a range of commonly encountered functional groups. The difluoromethyl esters of FDA approved drugs and pharmaceutically relevant molecules are also presented, demonstrating the potential for late-stage functionalization.
Difluoromethylation of the activated X–H bond and aliphatic thiols, and gem-difluorocyclopropenation of alkynes with difluorocarbene generated by decarboxylation are described.
<i>ortho</i>-Dialkylamino arylboranes as efficient reagents for difluorocarbene trapping
作者:Egor A. Ilin、Vladimir O. Smirnov、Alexander D. Volodin、Alexander A. Korlyukov、Alexander D. Dilman
DOI:10.1039/d0cc02567d
日期:——
Compounds bearing ortho-oriented dialkylamino and boryl groups can serve as efficient reagents to trap difluorocarbene leading to zwitterionic ammonium borates featuring N-CF2-B fragments. The reagents are shelf-stable and can be used as mechanistic probes for reactions proceeding via difluorocarbene.