Catalytic Enantioselective Addition of Sodium Bisulfite to Chalcones

At last! The addition of bisulfite to olefins, discovered over a century ago, remains the most straightforward approach to aliphatic sulfonic acids. A catalytic enantioselective procedure has now been realized that employs a bifunctional aminothiourea catalyst (see picture). Sulfonic acids were obtained from chalcones in high yields and high enantioselectivity and in both configurations.