A one-pot transformation of hydroxylated propargylic benzoate into chiral ketones featuring an O-heterocycle is realized via sequential gold catalysis and basic hydrolysis. The gold chemistry entails tandem 3,3-sigmatropic rearrangement and asymmetric cyclization of hydroxylated allenyl ester intermediates, which is achieved via asymmetric metal-ligand cooperation. The products were formed with good enantioselectivities despite the allenyl ester intermediate is racemic.

Abstract

By combining tandem asymmetric gold catalysis and subsequent stereoconvergent hydrolysis of enol ester in a one-pot process, hydroxylated propargylic esters are converted into chiral β-oxygenated ketones with mostly good enantiomeric ratios and in largely good to excellent yields. The product chiral center is formed via stereoselective cyclization of a hydroxylated allenyl ester intermediate, which is enabled by asymmetric gold-ligand cooperation.