Quaternary Carbon Centers via Electrochemical Direct Dehydroxylative Alkylation.

The construction of all-carbon quaternary centers remains a formidable challenge in organic synthesis due to the steric congestion and limited accessibility of suitable precursors. Herein, we report a modular electrochemical strategy for the direct dehydroxylative alkylation of tertiary alcohols via a polar-to-radical transduction mechanism. This unified activation platform enables C(sp3)─C(sp3) bond formation with electron-deficient alkenes and benzyl chlorides, employing readily available reagents under mild, operationally simple conditions. Key to this transformation is the use of halide-based reagents that mediate Lewis acid-promoted C─OH bond cleavage while enabling subsequent radical generation via cathodic reduction. The method exhibits broad substrate scope, including complex and functionalized tertiary alcohols, diverse Michael acceptors, and sterically hindered coupling partners. It is further applicable to the late-stage modification of bioactive molecules and scalable synthesis. Mechanistic studies support the involvement of both carbocation and carbon radical intermediates, validating the effectiveness of this dual-mode strategy. This work provides a general and practical approach to quaternary carbon construction from unactivated tertiary alcohols, expanding the synthetic toolbox for C(sp3)─C(sp3) bond formation.