A novel iodonium-ylide compound 2 that appends a trifluoromethylthio （SCF3） group is disclosed as a new, shelf-stable electrophilic trifluoromethylation reagent. Unlike known shelf-stable electrophilic trifluorometh...A novel iodonium-ylide compound 2 that appends a trifluoromethylthio （SCF3） group is disclosed as a new, shelf-stable electrophilic trifluoromethylation reagent. Unlike known shelf-stable electrophilic trifluoromethylation reagents, 2 has a stable SCF3 group which is activated by appending iodonium ylide under copper catalysis via sul- fonium ylide to generate a cationic trifluoromethyl （CF3） species. Reagent 2 was found to be an efficient electro- philic trifluoromethylation reagent for a wide range of silyl enol ethers 3 under copper catalysis. Cyclic and acyclic a-trifiuoromethyl ketones 4 were obtained by reagent 2 in moderate to good yields. On the other hand, a difluoro- methylthio analogue 5 did not affect intermolecular transfer difluoromethylation to substrates. Instead, intramolecu- lar 1,4-migration proceeded similar to the Stevens rearrangement to provide 6 in 21% yield, independent of the presence of nucleophiles 3.展开更多
文摘A novel iodonium-ylide compound 2 that appends a trifluoromethylthio （SCF3） group is disclosed as a new, shelf-stable electrophilic trifluoromethylation reagent. Unlike known shelf-stable electrophilic trifluoromethylation reagents, 2 has a stable SCF3 group which is activated by appending iodonium ylide under copper catalysis via sul- fonium ylide to generate a cationic trifluoromethyl （CF3） species. Reagent 2 was found to be an efficient electro- philic trifluoromethylation reagent for a wide range of silyl enol ethers 3 under copper catalysis. Cyclic and acyclic a-trifiuoromethyl ketones 4 were obtained by reagent 2 in moderate to good yields. On the other hand, a difluoro- methylthio analogue 5 did not affect intermolecular transfer difluoromethylation to substrates. Instead, intramolecu- lar 1,4-migration proceeded similar to the Stevens rearrangement to provide 6 in 21% yield, independent of the presence of nucleophiles 3.
