Photoredox-Induced Deaminative Radical-Cationic Three-Component Couplings with N-Alkylpyridinium Salts and Alkenes

N-Benzyl- and N-2 degrees-alkylpyridinium salts were engaged in visible-light-driven, photoredox-induced radical-cationic three-component couplings with N-methylmaleimide and acrylonitrile as radical acceptors, in combination with 1,1-diarylethylenes as donor alkenes. These multicomponent coupling reactions could be achieved under mild conditions, with high efficiency, and to furnish diverse 3,4-disubstituted pyrrolidin-2,5-dione products with high stereoselectivity. In addition, 2,3-diaryl-1,3-butadienes could be utilized as alternative donor alkene components, to furnish diastereomerically pure 1,2,3-trisubstituted 1,3-butadienes as the coupling products.