Substituent Effects in the Cycloaddition Reactions of Reissert Hydrofluoroborate Salts with Alkenes

Article abstract of DOI:10.1021/jo00321a027

An evaluation of substitutent effects has been undertaken of the cycloaddition of 2-aroyl-1,2-dihydroisoquinaldonitrile hydrofluoroborates (5) with substituted ethyl cinnamates, styrenes, stilbenes, and ethylenes.The cinnamates give mixtures of 2-(1-isoquinolyl)-3,5-diaryl-4-carbethoxypyrroles.The stilbenes give mixtures of 2-(1-isoquinolyl)-3,4,5-triarylpyrroles, but the styrenes give only 2-(1-isoquinolyl)-3,5-diarylpyrroles. 1-Hexene and cyclohexene undergo cycloaddition with 5 (Y=H) readily, but 2-heptene does not.The rates of many these reactions have been determined.The implications of the results with respect to the mechanism of reaction are discussed.