Gold(I)-catalyzed divergence in the reactivity of 3-silyloxy 1,6-enynes: pinacol-terminated vs claisen-terminated cyclization cascades

Org Lett. 2008 Jun 19;10(12):2605-7. doi: 10.1021/ol8008733. Epub 2008 May 14.

Abstract

On activation with catalytic amounts of gold(I) complexes, 3-silyloxy 1,6-enynes can react through two alternative pathways. In one, a cascade reaction consisting of carbocyclization and subsequent pinacol rearrangement takes place. In the second pathway, a heterocyclization is followed by a Claisen rearrangement. The reaction outcome differs depending on the substitution pattern of the 3-silyloxy 1,6-enynes and, more importantly, the electronic properties of the gold-bound phosphane ligand.