1,1-dibromo-2,2-difluoroethylene and n-butyllithium, with aldehydes or ketones, and subsequent acetylation, gives 2-bromo-3,3-difluoroallylic acetates. Elimination of these acetates with n-butyllithium affords 1,1-difluoroallenes in high yield. 3,3-Difluoro-2-iodoallylic acetates are similarly prepared from aldehydes or ketones on treatment with 2,2-difluoro-1-iodovinyllithium, generated from 1,1,
Copper-Catalyzed Protoarylation of <i>gem</i>-Difluoroallenes
作者:Wei Li、Cheng Wang、Mengdie Xiao、Li-Jie Cheng
DOI:10.1021/acs.orglett.3c03995
日期:2024.1.19
A copper-catalyzed protoarylation of gem-difluoroallenes with aryl boronic esters has been developed, enabling highly regioselective synthesis of gem-difluoroalkenes in high yields. The mild reaction conditions allow for a variety of functional groups to be tolerated, and the reaction can be extended to protoalkenylation of gem-difluoroallenes. The synthetic utility of this method has been demonstrated