Gold-catalyzed cyclizations of cis-enediynes: insights into the nature of gold-aryne interactions.

Golden aryne? Gold aryne complexes are inferred as transition states in dual gold-catalyzed cyclizations of cis-enediynes (see scheme; DCE = 1,2-dichloroethane). They are better described as ortho-aurophenyl cations, which react with weak nucleophiles and undergo facile intramolecular insertions into C(sp(3))-H bonds. Indanes, fused heteroarenes, and phenol derivatives are readily prepared using this method.