1,2-Migration of oxamoyl-protected alcohols via reversible C–H sampling

ABSTRACT Alcohols are ubiquitous in natural products and serve as versatile synthetic handles; however, the relocation of a hydroxyl group to an adjacent C–H site remains an underdeveloped yet highly valuable transformation. Herein, we report photocatalytic 1,2-translocation of oxamoyl-protected alcohols enabled by a reversible C–H sampling strategy. Utilizing a cooperative hydrogen atom transfer catalytic system, a range of carbon radicals are transiently generated, while the β-acyloxy alkyl radical selectively undergoes a 1,2-acyloxy shift to afford the rearranged product. The oxamoyl protecting group exhibits superior performance, likely accelerating the radical-acyloxy rearrangement while simultaneously enhancing β-hydrogen atom abstraction (HAA) probability. This redox-neutral methodology accommodates a broad substrate scope with predictable regio- and stereoselectivity, including the late-stage modification of complex bioactive molecules. Beyond facile hydrolytic removal, the oxamoyloxy handle can be directly converted into alkyl iodides, providing an additional entry point for further diverse functionalizations.