Reliably Regioselective Dialkyl Ether Cleavage with Mixed Boron Trihalides

Abstract

A protocol for the regioselective cleavage of unsymmetrical alkyl ethers to generate alkyl alcohol and alkyl bromide products is described. A mixture of trihaloboranes triggers this conversion and exhibits improved reactivity profiles (regioselectivity and yield) compared with BBr 3 alone. Additionally, this procedure allows the efficient synthesis of (B-Cl) dialkyl boronate esters. There are limited methods to generate acyclic dialkoxyboryl chlorides, and these intermediates constitute important synthons in main-group chemistry.