A mechanistic insight into the chemoselectivity of the reaction between 3-phenyl-2-propynenitrile, secondary phosphine oxides and pyridinoids

Abstract Reactions between 3-phenyl-2-propynenitrile, secondary phosphine oxides and pyridinoids have been implemented and studied. Pyridine and isoquinoline react with propynenitrile and phosphine oxides at room temperature according to the N-vinylation/C-phosphorylation scheme to afford (Z)-N-(2-cyano-1-phenyl)ethenyl phosphoryl-1,4-dihydropyridines or -1,2-dihydroiso quinolines. In the case of pyridine on heating (80–85 °°°C), the reaction gives 4-phosphorylpyridines ( S N H Ar reaction) and 3-phenyl-acrylonitrile oligomers.