ß-Cyclodextrin-NHC-Au(I)-Catalyzed Enantioconvergent 1,5-Enyne Cycloisomerizations.

ABSTRACT

Enantioconvergent transformations from racemic mixtures are attractive since they allow the generation of optically active products with full conversion despite the possibly adverse kinetic resolution process. When dealing with gold(I)-catalyzed cycloisomerizations, chirality transfer from the precursor is another possible diverting pathway, which renders enantioconvergence challenging. Not surprisingly, enantioconvergent Au(I)-catalyzed processes have remained extremely rare. Herein we show that cavity-driven catalysis using ß-cyclodextrin-NHC-Au(I) complexes brings opportunities to conduct highly enantioconvergent cycloisomerizations of 1,5-enynes, -enynols, and, -enynyl esters.