Asymmetric Construction of Acyclic 1,3-Nonadjacent Stereogenic Centers Containing a Tetrasubstituted Carbon through Diastereoselective Alkylation of Benzyl Sulfone Derivatives

A strategy for the asymmetric construction of acyclic 1,3-nonadjacent stereogenic centers containing a tetrasubstituted carbon has been established, which involves an enantioselective addition reaction and a subsequent chelate-controlled diastereoselective alkylation reaction. Specifically, the enantioselective addition reaction of alpha-thioacetamides with alpha-phenyl-substituted vinyl sulfones under chiral Br & oslash;nsted base catalysis and the subsequent LDA-mediated diastereoselective methylation, allylation and benzylation at the alpha position of the sulfonyl group of the adducts afforded the desired enantio-enriched products having 1,3-nonadjacent stereogenic centers containing a tetrasubstituted carbon in a highly stereoselective manner.