Metal-Free Direct Construction of 2-(Oxazol-5-yl)phenols from N-Phenoxyamides and Alkynylbenziodoxolones via Sequential [3,3]-Rearrangement/Cyclization.

A mild and straightforward synthetic protocol for the construction of 2-(oxazol-5-yl)phenol derivatives promoted by K2CO3 from N-phenoxyamides and alkynylbenziodoxolones at room temperature has been developed. Importantly, this protocol involves a tandem sequence that includes [3,3]-rearrangement/alkylidene carbene insertion/Michael addition/cyclization. The metal-free conditions, broad substrate scope, and simple execution make this novel protocol very attractive.