Alcohols as Alkyl Synthons Enabled by Photoredox-Catalyzed Deoxygenative Activation

Alcohols are abundant with versatile structural variety and have ample use as pivotal functional groups in numerous organic processes. Because of their frequent occurrence in enumerable natural products, bioactive molecules, and medicinal components, alcohol functionalities provide a promising scope of research to advance the operational diversity for improving clinical success. Recent years have witnessed the design of modern C–C and C–heteroatom bond-forming approaches with easily accessible and commercially available unactivated aliphatic alcohols as native adaptive sp3 handles, hence offering groundbreaking transformative pathways for the functionalization of complex molecular architectures. The judicial application of appropriate activating groups to generate the alkyl radical from the alcohol through sp3 C–O bond fragmentation and employ it as a potential alkylating agent unfolds unique synthetic strategies, thereby replacing the obvious requirement of alkyl halides. This review elaborately discusses the recent trends regarding using alcohols as the C(sp3)-centered alkylating agent in various chemical transformations by exploiting different activation modes for the disrupter of the C–O bond under photoredox catalysis. The presentation is organized by the nature of the activation of the alcohol scaffolds, the kind of bond formation, and the progress achieved in this domain since the original discovery by providing illustrative examples with mechanistic details, with a focus on difficulties and future prospects.