Kinetic Resolution of β-Sulfonyl Ketones through Enantioselective β-Elimination using a Cation-Binding Polyether Catalyst

Reported herein is the first enantioselective beta-elimination reaction catalyzed by a chiral cation-binding polyether. By using this catalytic protocol, a wide range of beta-sulfonyl ketones could be effectively resolved with high stereoselectivity (S up to > 300). Key to the success of this process is the favorable secondary interactions of the catalyst with the Lewis basic groups on the sulfone substrate. The enone product of this process can be easily converted into the racemic starting material, and allows an effective recycling and overall synthesis of chiral beta-sulfonyl ketones in high yield and excellent enantioselectivity.