Au(III)-Catalyzed Domino Cyclization/Functionalization Reactions: an Entry to Heterocycles

Accessibility of highly functionalized polyheterocyclic compounds with efficient catalytic methods represents a long-standing challenge for organic chemists. The use of transition-metal catalysts and the recent development of gold(III) complexes open up new opportunities. Herein, we report straightforward gold(III)-catalyzed domino cyclization/functionalization reactions to access scaffolds of biological interest. The methodology developed here is applied to the synthesis of isochromenes through cyclofunctionalization of 2-ethynylarylaldehyde derivatives and to the cycloisomerization of 1,6-enynes into (poly)heterocyclic compounds. The NHC-type gold(III) catalyst showed high tolerance to functional groups along with superior reactivity compared to gold(I), highlighting the potential of such gold(III) complexes to catalyze synthetic transformations.