Micro-electro-flow catalyzed (μ-EFC) ultra-fast cross-electrophile coupling of activated C(sp3)–O bonds

Abstract

Over the past few decades, many batch process strategies have been developed that allow activated C(sp³)–O bonds to facilitate the synthesis of cross-electrophile coupling products. However, in these processes, a transition metal catalyst or an organic photocatalyst with a stoichiometric amount of oxidant or a reductant is the prerequisite. Indeed, the expensive catalyst, reductant, and oxidant and low surface-to-volume ratio for the gas–liquid reaction serve as major challenges in the field of cross-electrophile coupling and organosulfur chemistry. Herein, we report an electro-micro-flow induced cross-electrophile coupling of activated C(sp³)–O bonds with CO₂ to generate aliphatic carboxylic acids via sequential reactions of sulfonium salts followed by replacement of CO₂ with CS₂, an aldehyde, a ketone, and electron-deficient olefins, to obtain the corresponding dithiol acid, deoxygenated Barbier-type product, and 1,4-addition product.