Asymmetric Au(i)-catalyzed synthesis of bicyclo[4.1.0]heptene derivatives via a cycloisomerization process of 1,6-enynes

The enantioselective asymmetric gold-catalyzed cycloisomerization reactions of heteroatom tethered 1,6-enynes are conducted in the presence of a chiral cationic Au(i) catalyst ((R)-4-MeO-3,5-(t-Bu)(2)-MeOBIPHEP-(AuCl)(2)/AgOTf system) in toluene under mild conditions and lead to functionalized bicyclo[4.1.0]heptene derivatives in excellent enantiomeric excesses ranging from 90-98%.