Synthesis and characterization of click-decahydrodecaborate derivatives by the copper(I) catalyzed [3+2] azide-alkyne cycloaddition reaction

Abstract

A facile and rapid access to a wide range of novel 1,2,3-triazoles bearing closo-decahydrodecaborate anion [B10H10]2− has been developed through an efficient general synthetic approach. It is based on the nucleophilic cleavage of 2-tetrahydrofuranium decaborate with sodium azide to form the known [B10H9O(CH2)4N3]2−. This azide derivative obtained reacted with various linear alkynes (phenylacetylene, 5-chloro-1-pentyne, heptyne, octyne, N-Boc-propargylamine and diethyl acetylenedicarboxylate) by the copper(I) catalyzed [3 + 2] azide-alkyne cycloaddition reaction (CuAAC) to form click-decaborate derivatives. In absence of copper and with strained cycloalkynes, the reaction is a strain-promoted cycloalkyne-azide cycloaddition (SPAAC). All click-decaborate derivatives were obtained in pure form with high yields and characterized by 11B, 1H and 13C NMR, MS-ESI, and Atomic Absorption.