摘要

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 sulfonium ylide to generate a cationic trifluoromethyl (CF3) species. Reagent 2 was found to be an efficient electrophilic trifluoromethylation reagent for a wide range of silyl enol ethers 3 under copper catalysis. Cyclic and acyclic a-trifluoromethyl ketones 4 were obtained by reagent 2 in moderate to good yields. On the other hand, a difluoromethylthio analogue 5 did not affect intermolecular transfer difluoromethylation to substrates. Instead, intramolecular 1,4-migration proceeded similar to the Stevens rearrangement to provide 6 in 21% yield, independent of the presence of nucleophiles 3.

  • 出版日期2016-5