The reaction of N-benzyl alpha-amino acid ethyl esters with ethylmagnesium bromide in the presence of a catalytic amount of titanium tetraisopropoxide leads to formation of the corresponding 1-aminoalkyl-1-cyclopropanols in high yields. Hydrogenation of the latter over palladium catalyst ensures selective removal of one or two protecting benzyl groups from the nitrogen atom.
Conjugated imines and iminium salts as versatile acceptors of nucleophiles
作者:Makoto Shimizu、Iwao Hachiya、Isao Mizota
DOI:10.1039/b814930e
日期:——
development of synthetic methodologies where nucleophilicaddition reactions to imino carbons are utilized in crucial steps. This article summarizes double nucleophilicaddition reactions with alpha,beta-unsaturated aldimines, addition reactions using alkynyl imines, "umpoled" reactions of alpha-imino esters, and the use of iminium salts as reactive electrophiles.