Copper-Catalyzed C–H Difluoroalkylations and Perfluoroalkylations of Alkenes and (Hetero)arenes
作者:Xiaoyang Wang、Shuang Zhao、Jing Liu、Dingsheng Zhu、Minjie Guo、Xiangyang Tang、Guangwei Wang
DOI:10.1021/acs.orglett.7b01712
日期:2017.8.18
A general and facile syntheticmethod for C(sp2)–H difluoroalkylations and perfluoroalkylations of alkenes and (hetero)arenes with commercially available fluoroalkyl halides has been developed with a copper-amine catalyst system. This method is characterized by high yields, mild reaction conditions, low-cost catalyst, broad substrate scope, and excellent functional group compatibility, therefore providing
Direct Introduction of Ethoxycarbonyldifluoromethyl-Group to Heteroarenes with Ethyl Bromodifluoroacetate via Visible-Light Photocatalysis
作者:Qingyu Lin、Lingling Chu、Feng-Ling Qing
DOI:10.1002/cjoc.201300411
日期:2013.7
A mild and versatile approach for the directintroduction of ethoxycarbonyldifluoromethyl‐group to heteroarenesvia visible‐light photocatalysis has been developed. The new photoredox protocol has enabled the difluoromethylenation of heteroarenes containing a wide range of common functional groups under mild conditions.
Copper‐Catalyzed C−H Difluoroalkylation of Coumarins with Fluoroalkyl Bromides
作者:Min Rao、Zhenwei Wei、Yaofeng Yuan、Jiajia Cheng
DOI:10.1002/cctc.202001025
日期:2020.10.20
An efficient method for the copper‐catalyzed selective C−H difluoroalkylation of coumarins and with low cost and readily available ethylbromodifluoroacetate and N‐phenyl bromodifluoroacetamide has been reported. This reaction exhibits good functional group tolerance with respect to coumarins and difluoroalkylation reagents, and several redox‐sensitive substrates have been successfully C−H difluoroalkylated
Novel and facile aromatic and heteroaromatic substitutions with difluoromethyl radicals bearing electron-withdrawing group generated by the photo-initiated Se-CF 2 bond cleavage of ethyl α,α-difluoro-α-(phenylseleno)acetate and diethyl α,α-difluoromethyl-α-(phenylseleno)phosphonate were successfully carried out to provide the corresponding a-aryl-α,α-difluoroacetates and α-aryl-α,α-difluoromethylphosphonates
transfer at an early stage followed by elimination of phenylselenol from the adducts once formed to provide the unsaturated difluoromethylene adducts selectively. This novel photochemical method was successfully extended to aromatic and heteroaromatic substitutions to provide the corresponding α-aryl-α,α-difluoroacetates and α-aryl-α,α-difluoromethylphosphonates in good to moderate yields.