Reactions of Azoalkenes derived from Hydrazones of Ethyl Bromopyruvate with Electron Rich Alkenes and Heterocycles

Article abstract of DOI:10.1016/S0040-4020(01)80992-3

Three hydrazones of ethyl bromopyruvate, the dinitrophenylhydrazone 2a, the toluene-4-sulphonylhydrazone 2b and the t-butoxycarbonylhydrazone 2c, have been reacted with a series of nucleophilic alkenes and heterocycles in the presence of sodium carbonate.Azoalkenes 3 are presumed as intermediates and adducts have been isolated.The azoalkenes derived from hydrazones 2a and 2c are found to be useful electrophiles and electrophilic dienes.Keywords: Azoalkenes; cycloaddition; ethyl bromopyruvate hydrazones; indoles; tetrahydropyridazines