Substrate-Controlled Product Divergence: Silver-Catalyzed Reaction of Trifluoromethyl Ketones with Terminal Alkynes

A distinct dichotomy in product distribution was initially observed in the silver-catalyzed
reaction of trifluoromethyl (CF3) ketones with terminal
alkynes having two different types of electronic natures. The domino
reaction smoothly proceeded almost exclusively with high stereoselectivity
with terminal alkynes containing ester groups, whereas alkynylation
occurred in good yield when terminal alkynes containing aryl or alkyl
groups were present. The results indicated that the electronic nature
of terminal alkynes can act as a switch that enables either the domino
reaction or alkynylation between terminal alkynes and CF3 ketones.