Bismuth-catalyzed cyclization of amino-1,6-enynes

Bi(OTf)(3) effectively catalyzed the cyclization of amino-1,6-enynes, leading to bicyclic amine and cyclopentadienyl amino compounds. The selectivity of the products depends on the substitution pattern of the olefinic moiety. F-19 NMR trace experiment of the reaction and other results indicate a novel alkynophilicity of the bismuth species. (C) 2008 Wiley Periodicals, Inc.