Synthesis of Difluoroalkenes from Thiocarbonyl Compounds via Difluorothiiranes: Electrophilic Counterpart to Wittig-Type Difluoromethylidenation
作者:Kohei Fuchibe、Atsushi Yamada、Kosei Hachinohe、Kana Matsumoto、Ryo Takayama、Junji Ichikawa
DOI:10.1246/bcsj.20210248
日期:2021.10.15
reaction described herein is an electrophilic counterpart to the Wittig-type (nucleophilic) difluoroalkene synthesis starting from carbonyl compounds. The electrophilic difluoromethylidenation facilitated the synthesis of sulfanylated and diarylated 1,1-difluoroalkenes, including sterically hindered ones, which are inaccessible by nucleophilic difluoromethylidenation.
1,1-二氟-1-烯烃的合成是通过在质子海绵催化剂即 1,8-双(二甲氨基)萘。生成的亲电子二氟卡宾 (:CF 2) 与硫代羰基官能团反应形成 2,2-二氟硫杂环丙烷中间体,其脱硫在 Barton-Kellogg 型二氟甲基化中提供产物。本文所述的反应是从羰基化合物开始的 Wittig 型(亲核)二氟烯烃合成的亲电对应物。亲电二氟甲基化促进了硫烷基化和二芳基化 1,1-二氟烯烃的合成,包括空间位阻的,这是亲核二氟甲基化无法达到的。