Rh-Catalyzed Asymmetric Hydrogenation of beta-Substituted-beta-thio-alpha.beta-unsaturated Esters: Expeditious Access to Chiral Organic Sulfides

Rh/bifunctional bisphosphine-thiourea ligand (ZhaoPhos)-catalyzed asymmetric hydorgenation of both (Z)-and (E)-isomers of beta-substituted-beta-thio-alpha,beta-unsaturated esters was successfully developed. This new asymmetric catalytic methodology provided highly efficient access to two enantiomers of chiral organic sulfides ethyl beta-substituted-beta-thio-propanoates with excellent results (up to 99% yield and >99% ee for (Z)-substrates, up to 99% yield and 98% ee for (E)-substrates, TON up to 5000), which are important intermediates in organic synthesis.