A highly efficient and eco-friendly method for the synthesis of 1,3-indandione ring-fused 3-oxindoles bearing two contiguous quaternary stereocenters via an aldol reaction in aqueous media
method for the synthesis of oxindoles featuring two contiguous quaternary carbon centers via an aldol reaction starting from various 3-substituted oxindoles has been established. A wide variety of such featured multi-substituted 1,3-indandione ring-fused 3-oxindole scaffolds were obtained smoothly in good yields (up to 98%) employing the most green of solvents, namely water, as reaction medium. Furthermore