Division of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba , Tsukuba, Ibaraki 305-8571, Japan.
Org Lett. 2017 Oct 6;19(19):5050-5053. doi: 10.1021/acs.orglett.7b02222. Epub 2017 Sep 21.
Electrophilic difluoromethylidenation of dithioesters was achieved in high yields via the reaction with difluorocarbene. When aryl or alkyl dithiocarboxylates were treated with trimethylsilyl 2,2-difluoro-2-fluorosulfonylacetate in the presence of 5 mol % of a Proton Sponge catalyst, the in situ generated difluorocarbene reacted with the dithioesters to afford 2-sulfanylated 1,1-difluoro-1-alkenes via difluorothiiranes. This reaction can be considered as an electrophilic counterpart of the Wittig-type difluoromethylidenation of carbonyl compounds with nucleophilic difluoromethylene ylides.
二硫代酯的亲电二氟甲叉化反应通过与二氟卡宾反应高产率地实现。当芳基或烷基二硫代羧酸酯在 5 mol%质子海绵催化剂的存在下与三甲基硅基 2,2-二氟-2-氟磺酰基乙酸酯反应时，原位生成的二氟卡宾与二硫代酯反应，通过二氟硫代亚胺，得到 2-硫代-1,1-二氟-1-烯烃。该反应可以被认为是羰基化合物与亲核二氟甲叉基叶立德的威蒂希型二氟甲叉化反应的亲电对应物。
