Recyclable Indium(III) Chloride Catalyzed Site-Selective Double Substitution in One Pot for the Synthesis of Isatin N-Ribonucleosides under Microwave Irradiation

摘要

A novel one-pot synthesis of isatin N-ribonucleosides from N-phenylribosylamines and diethyl oxalate in ethanol catalyzed by recyclable indium(III) chloride under microwave irradiation has been developed. The transformation consists of indium(III) chloride catalyzed nucleophilic substitution by iV-phenylribosyl-amines on diethyl oxalate followed by rapid intramolecular electro-philic substitution, which results in annulation of a five-membered nitrogen heterocycle on to the benzene ring yielding isatin N-ribo-nucleosides. The reaction proceeded smoothly in quantitative yields at ambient temperatures. The starting materials, iV-phenylribosyl-amines, were prepared by indium(m) chloride catalyzed nucleophilic substitution of the anomeric hydroxy group of (3-D-ribofuranose by an arylamine under microwave irradiation.