Versatile positional editing of diverse functional groups through radical 1,2-boron shifts

Functional groups are central to the property, function, and reactivity of organic molecules. Their identity, spatial orientation–and specific location–can influence a molecule’s behavior and fate.1 The direct, precise “editing” of the position of a given functional group without altering other parts of the molecule, particularly at late stages, represents a strategy that is complementary to traditional synthetic logic2 and valuable for molecular diversification.3,4 However, only a limited number of methods for such functional group positional editing exist, and these often lack generality as they are typically tailored to specific functional groups, often require the design of specialized substrates, or both. Here we report a general strategy for positional editing of a diverse set of functional groups through a short sequence to access a myriad of corresponding positional isomers. This approach is realized by developing a catalytic, direct 1,2-transposition of pinacolboryl group that occurs across a wide range of substrates and harnessing the well-appreciated synthetic versatility of organoboron. Key to our design is the identification of hydrogen atom transfer (HAT) catalysts possessing suitable rate constants, which control the reaction efficiency and selectivities. Our work establishes a generalized mechanistic framework for designing direct 1,2-transposition reactions of other applicable functional groups, and more broadly, has the potential to enable the positional editing of many functional groups, including those that do not undergo radical rearrangements.