Synthesis of Highly Functionalized Chiral 3,3′-Disubstituted Oxindoles via an Organocatalytic Enantioselective Michael Addition of Nitroalkanes to Indolylidenecyanoacetates

An efficient bifunctional cinchona alkaloid derived thiourea-promoted enantioselective conjugate addition of nitroalkanes to indolylidenecyanoacetates has been developed under neat conditions. The process leads to synthetically interesting densely functionalized 3,3'-disubstituted oxindoles with creation of up to three stereogenic centers.