The first example of a “click” reaction with a carboranyl azide and an olefin

Abstract

While typical organic azides have long been known to undergo 1–3 dipolar cycloadditions with strained CC multiple bonds, such chemistry has never been reported between organomimetic carboranyl azides and alkenes. Here we show that the carborane o-PhCN3CB10H10 readily undergoes cycloaddition with norbornene at ambient temperature to afford the corresponding triazole adduct with perfect exo-selectivity. The structure of the ensuing heterocycle was unambiguously determined by multinuclear NMR, correlation NMR, and single crystal X-ray diffraction experiments. This first example of such reactivity demonstrates a method to easily introduce carborane clusters directly to scaffolds of interest, without having an organic spacer between the azide functionality and cluster.