Functionalized organolithium reagents. 9. Lithiation and isomerization of allylic amines as a general route to enamines and their carbonyl derivatives

Abstract

[3-(Diphenylamino)-2-propenyl]lithium, readily prepared by the lithiation of allyldipenylamine with n-butyllithium in THF, undergoes alkylation either with organic halides or with carbonyl or azomethine derivatives to yield enamines, which can be converted by protons or other electrophiles into aldehydes or into five-membered heterocycles; lithiation of such allyldiarylamines with other reagents leads principally to isomerization to enamines (with lithium diisopropylamide) or to carbenoid intermediates (tert-butyllithium and potassium tert-butoxide)