Au(III)-Catalyzed Domino Cyclization / Functionalization Reactions: an Efficient 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 opens new opportunities. We herein report a 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 compare to gold(I), highlighting the potential of such gold(III) complexes to catalyze synthetic transformations.