Nickel-catalyzed cross-coupling of N-acyl benzotriazoles with oxiranes and oxetanes for the synthesis of β-haloethyl and γ-halopropyl esters

Abstract

Herein we report a Ni-catalyzed cross-coupling reaction between N-acyl benzotriazoles, epoxides and trimethylsilyl halides, which gives rise to β-haloethyl esters with good yields and wide substrate scope. This catalytic system also enables the reaction involving oxetanes affording γ-halopropyl esters. The cyclic triazene moiety in benzotriazole is proved to be essential for the unique reactivity of these amides. Preliminary mechanistic studies point to the intermediacy of 2-chloroethyl trimethylsilyl ether and the possible pathway via σ-bond metathesis.