Regioselectivity in dipolar cycloaddition reactions of <i>N</i>‐phenylcinnamonitrilimine

Abstract

Abstract The regioselectivity of the cycloadditions of α,β‐unsaturated nitrilimine derived from N ‐phenylcinnamo‐hydrazidoyl chloride 2 to C = Se, C = S and C = C double bonds of the resonance stabilized selenocyanate and thiocyanate anions, enol tautomer of dibenzoylmethane and benzalacetophenone was investigated. The results indicate that the reactions studied are dipole‐LUMO‐dipolarophile‐HOMO controlled and that the larger orbital coefficient in the LUMO of N ‐phenylcinnamonitrilimine is on the carbon atom bearing the styryl group. The structures of the cycloadducts were assigned and confirmed on the basis of their elemental analyses and spectra.