Computational study on the mechanism of metal-free photochemical
borylation of aryl halides
Abstract
C-radical borylation is an significant approach for the construction of
carbon−boron bond. Photochemical borylation of aryl halides successfully
applied this strategy. However, precise mechanisms, such as the
generation of aryl radicals and the role of base additive(TMDAM) and
water, remain controversy in these reactions. In this study,
photochemical borylation of aryl halides has been researched by density
functional theory (DFT) calculations. Indeed, the homolytic cleavage of
the C−X bond under irradiation with UV-light is a key step for
generation of aryl radicals. Nevertheless, the generation of aryl
radicals may also undergo the process of single electron transfer and
the heterolytic carbon-halogen bond cleavage sequence, and the latter is
favorable during the reaction.