Rhodium-Catalyzed [5+2] Cycloaddition of 3-Acyloxy-1,4-enyne with Alkene or Allene

We recently developed a completely new type of Rh-catalyzed [5+2] cycloaddition by using 3-acyloxy-1,4-enyne (ACE) as the 5-carbon building block. In this update, we show that ACE can undergo intramolecular [5+2] cycloaddition with either an alkene or an allene in the presence of an appropriate rhodium catalyst and ligands to afford bicyclic compounds with multiple stereogenic centers. In most cases, cis-fused bicyclo[5.3.0]decadienes are prepared highly diastereoselectively.