Transition-metal-free electrochemical cross-electrophile coupling of activated benzyl alcohols and primary alkyl bromides.

Chen, Guang; Huang, Changhao; Luo, Like; Tian, Dayu; Wang, Xiaocheng; Zhang, Hai-Jun · Sci Adv · 2026

basic_science · Level V

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Abstract

Cross-electrophile coupling (XEC) has emerged as a powerful strategy for constructing carbon─carbon bonds. Here, we report the first transition-metal-free electrochemical XEC between readily available benzyl alcohol derivatives and primary alkyl bromides, enabling the efficient construction of C(sp<sup>3</sup>)─C(sp<sup>3</sup>) bonds to access valuable benzylic quaternary and tertiary carbon centers. This method expands the reaction profiles of both benzyl alcohols and electrochemistry. A key to unlocking this transformation is the identification of 4-<i>tert</i>-butylbenzoyl (TBBz) as an effective activating group for benzyl alcohols. This modular protocol features broad substrate scope, compatibility with CO<sub>2</sub> and chlorosilanes as coupling partners, and is amenable to gram-scale synthesis. The synthetic utility of this method is exemplified by the simplified synthesis of high-value commercial building blocks and advanced intermediates for bioactive compounds, as well as the facile access to bioisosteric analogs of drug molecules.