Stable synthetic equivalents of N-unsubstituted imines: Part 1. Synthesis

Abstract

The key role of imines in organic synthesis, for example in the synthesis of amine derivatives and nitrogen heterocycles, is well known. However, the instability of N-unsubstituted imines is often an obstacle to the selection of synthesis strategy. Therefore, it is rather topical to design stable imines with a readily removable group at the nitrogen atom. The first part of this review deals with the methods of synthesis of N-sulfinyl imines (including chiral), N-sulfonyl imines, N-phosphinoyl imines, N-acylimines, N-silylimines, N-(hexopyranosyl)imines, N-benzylimines, N-(methoxyphenyl)imines, N-allylimines, 1,3,5-trisubstituted 2,4-diazapenta-1,4-dienes, and N-(1-hydroxyethyl-2,2,2-trichloro)imines and the methods for removing these protective groups.