Gold‐Catalyzed Hydroarylation of Alkynes

The hydroarylation of aryl‐substituted alkynes by substituted electron‐rich arenes is catalyzed by AuCl 3 activated by such silver salts as AgSbF 6 . In the case of terminal alkynes, complete regioselectivity in favor of the 1,1‐disubstituted olefin is observed. In the case of electron‐poor alkynes such as acetylenecarboxylic acid ester, gold( I ) complexes such as [Ph 3 PAuCl] activated by Ag salts or BF 3 ·OEt 2 are the best catalysts, resulting in opposite regioselectivity and high degrees of ( Z )‐selectivity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)