An Alternative Reaction Outcome in the Gold-Catalyzed Rearrangement of 1-Alkynyloxiranes

The gold(III)-catalyzed rearrangement of tetrasubstituted 1-alkynyloxiranes is described. This transformation led to a different reaction outcome with respect to related substrates previously studied. Thus, tertiary a-alkynylketones or alkynols can be selectively obtained. Moreover, gold(III) proved capable to catalyze the rearrangement of simple epoxides. These results indicate that gold(III) complexes act as oxophilic Lewis acids rather than p-acids in these transformations.