Benzylic C(sp³)–H Functionalization by Photo Redox Catalysis

Abstract

Benzylic C–H bonds, due to their enhanced reactivity, offer a valuable platform for the selective functionalization in organic synthesis. Recent advancements in catalytic methods have enabled direct transformation of these sp³-hybridized sites under mild conditions. Transition-metal catalysis, photo redox strategies, and radical pathways have shown particular promise. These approaches allow for the construction of diverse C–C and C–X (X = N, O, Br, S) bonds. The presence of electron-withdrawing groups on the substrates significantly reduces the reaction efficiency, representing a limitation of these methodologies. The ability to functionalize benzylic positions through intermolecular and intramolecular methods expand the toolbox for late-stage modification of complex molecules. Such transformations are increasingly important in pharmaceutical and materials chemistry.

Keywords

Benzylic - Intramolecular - Intermolecular - Ffunctionalization - Photo redox catalysis

Publication History

Received: 24 September 2025

Accepted after revision: 10 December 2025

Article published online:
15 January 2026

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