Ring-Opening α,β-Difunctionalization of Cyclopropanols with Azides Enables 4-Keto-Functionalized 1,2,3-Triazole Synthesis

Abstract

Selective C−C bond cleavage and transformation of organic small molecules to create products of increased value are one of the central goals in organic chemistry. In this study, we have developed a novel TEMPO-mediated ring-opening α,β-difunctionalization of cyclopropyl alcohols with organic azides to prepare structurally important 4-keto-1,2,3-triazoles under metal-and additive-free conditions. This protocol not only provides a straightforward and efficient method for the synthesis of 4-ketofunctionalized 1,2,3-triazoles in one pot but also accomplishes the goal of constructing α,β-double C−N bonds via the ring opening of cyclopropyl alcohols for the first time. Additionally, the application of the skeletons of drugs and natural products and the synthesis of Kv1.5 channel blocker 4u further demonstrate the synthetic potential and practicability of this strategy.