Electrochemical radical 1,4-dialkoxylation of 1,3-dienes to access (E)-1,4-diether alkenes

Abstract

A highly selective 1,4-dialkoxylation of dienes through direct electrolysis under mild reaction conditions has been developed. With widely available alcohols as alkoxyl sources, a variety of Z/E-mixture 1,3-dienes undergo dialkoxylation reaction to afford 1,4-diether alkenes with high E selectivity. Mechanistic studies revealed that alkoxyl radicals are generated during the electrolysis process. These alkoxy radicals undergo addition to the diene, followed by isomerization to form a more stable radical intermediate and subsequent oxidative coupling, thereby enabling the 1,4-selective transformation. Calculation experiments further support that the isomerization to a more stable intermediate contributes to the observed high E- and 1,4-selectivity, enabling efficiently access to (E)-1,4-diether internal alkenes.