A New Gold-Catalyzed C−C Bond Formation

With a d8 configuration equivalent to palladium(II), gold(III) also catalyzes a number of interesting and effective reactions. The cycloisomerization of allenyl ketones with 1 mol % of catalyst requires about one hour with [PdCl2(MeCN)2] but only a minute with AuCl3; a selective cross coupling of these substrates with Michael acceptors (see scheme) is possible only with the gold catalyst.