Base-catalyzed cyclization of N -sulfonyl propargylamides to sulfonylmethyl-substituted oxazoles via sulfonyl migration

摘要

The reaction of N-sulfonyl propargylamides in the presence of a base catalyst selectively affords 5-sulfonylmethyl oxazoles via 1,4-sulfonyl migration. Allenes have been established as the key intermediates. Experimental evidence has been provided to support a two-step mechanism in the cyclization.