Enantioselective Desymmetrization of Bisphenol Derivatives by Organocatalytic Sulfonylation

Chiral 1,1‐diarylalkanes are synthesized by enantioselective desymmetrization of bisphenol derivatives through an organocatalytic sulfonylation reaction. The methodology involves the selective sulfonylation of one enantiotopic hydroxyl group of a bisphenol using a sulfonyl chloride with a chiral thiourea catalyst in a CHCl 3 /H 2 O system under basic conditions. The resulting products are obtained in good to high yields (up to 97%) with high enantioselectivity (up to 90.5:9.5 er). Remarkably, compounds that are almost enantiomerically pure can be obtained from the mother liquor after crystallization.