The use of propargyl carboxylates as substrates for the electrophilic activation of alkynes has been studied extensively and a variety of useful transformations have been developed utilizing intermediates generated by 1, 2-or 1, 3-acyloxy migration of the carboxylates.[1] As part of our ongoing research into the [W (CO) 5 (L)]-and [ReCl (CO) 4 (L)]-catalyzed cyclization of acetylenic silyl enol ethers through electrophilic activation of the alkyne ...
