Photoelectron transfer catalysed reactions of amines with α,β-unsaturated esters and acrylonitrile using different sensitizers

Abstract

A variety of sensitizers were screened for their ability to photocatalyse efficiently the carbon-carbon bond forming reactions between primary and secondary amines with electron-deficient olefinic substrates, such as α,β-unsaturated and acrylonitrile. The reactions with α,β-unsaturated esters led to the formation of lactams as the major products. Dicyanoanthracene and acridone were found to be inefficient, while anthraquinone, benzophenone, anthrone and xanthone photocatalyse these reactions with moderate efficiency. The anthraquinone-2-sodium sulphonate catalysed addition of tertiary amines to α,β-unsaturated esters in aqueous medium also yielded lactams as the major products. Reasonable mechanisms have been suggested for the formation of the different products.