Enantioselective Nucleophilic Vinylic Substitution (SNV) toward 3-Alkenyl-bisoxindoles Facilitated by C6′ Steric Bulk of Cinchona Alkaloid

A C6' bulky substituted quinine-catalyzed SNV reaction between 3-substituted oxindole and (E)-3-(nitromethylene)-oxindole was developed. This enantioselective C(sp3)-C(sp2) coupling furnished bisoxindole scaffolds featuring a vinyl-substituted all-carbon quaternary stereocenter with high stereoselectivities. In addition, the gram-scale synthesis and synthetic post-transformations were conducted to demonstrate the potential synthetic usefulness.