Nanocrystalline Sn for Photoelectrocatalytic Synthesis of Stereocontrolled Oxime

Abstract Oximes (including E / Z configurations) stand as pivotal intermediates in the synthesis of high‐value chemicals, with Z ‐configured oximes garnering significant attention owing to their distinctive pharmacological activities and specialized applications. However, the construction of thermodynamically labile Z ‐oximes remains formidable challenges, characterized by inherent kinetic barriers and rigorous reaction conditions. Herein, we pioneeringly develop a photoelectromediated method for synthesizing Z ‐oxime from nitrite and aldehyde for the first time, avoiding involving unstable hydroxylamine reagents and corrosive concentrated hydrochloric acid. Predominantly E ‐configuration benzaldoxime ( Z : E = 0.08) was obtained in the electrocatalytic system. Notably, after introducing photomediated energy transfer (EnT), the ratio of Z:E ‐configuration has increased to 13 times (1.06) with a well‐designed porous nanocrystalline Sn in carbon nanotubes (Sn–C). The mechanism study reveals that the Sn–C presented a fast kinetic of *NH 2 OH production, which rapidly coupled with benzaldehyde to form E ‐oxime, then following a triplet‐triplet EnT mechanism to generate Z ‐benzaldoxime under the assistant of photocatalyst. This study provides a sustainable synthetic protocol for oximes characterized by notable green chemistry attributes, while establishing an innovative stereoselective synthetic framework that addresses long‐standing challenges in the precise control of oxime E / Z isomerism. This work thereby may advance both the fundamental understanding of oxime chemistry and its practical applications in pharmaceutical synthesis.