Chemo- and stereoselective reduction of enaminones for the preparation of biologically active compounds

Abstract

The chemistry of the preparation of β-enamino ketones and β-enamino esters and their use as useful starting materials in reductive procedures for the preparation of biologically active natural products is described. Enaminones are very stable compounds and can be easily prepared, starting from cheap and easily available starting materials. Therefore they constitute also excellent starting materials in organic synthesis. Several chemo- and regioselective methodologies for their preparation have been developed also recently. The possibility to use enantiopure chiral amines for the preparation of enamino ketones and enamino esters makes available useful starting materials for the preparation of enantiopure biologically active compounds. Moreover, it is possible to obtain more complex enaminones by regio- and stereoselective functionalization of the more accessible ones. Recently numerous methodologies for the chemo- and stereoselective reduction of enaminones have been developed, that constitute useful alternative pathways to the numerous literature procedures for the preparation of γ-amino alcohols, β-amino acids, aminoalkyl phenols and their derivatives. γ-Aminoalcohols and aminoalkylphenols are a class of very stable compounds that find useful applications in asymmetric catalysis as chelant for the preparation of chiral enantiopure metallic catalysts.