Variable regioselectivity in reactions of N-lithio-N-vinylaniline with arenedicarboxylates and α,β-unsaturated esters
Regioselectivity patterns for the reactions of N-lithio-N-vinylaniline with several arenedicarboxylates and esters of α,β-unsaturated acids are reported. N-Lithio-N-vinylaniline reacted at both of its ambident anionic sites, to give β-enamino ketones and amide derivatives. A bridgehead compound resulting from cycloadditions involving N-lithio-N-vinylaniline was also formed in the reactions with ethyl cinnamate and ethyl phenylpropiolate. The structures of all compounds formed were fully characterised by NMR techniques.