Yubing's serendipitous discovery is out in Angew Chem., congratulations!

Skeletal editing of aromatic heterocycles has witnessed significant advancements in recent years, particularly in the editing of nitrogen- and oxygen-containing heterocycles. However, the single-atom editing of sulfur-containing heterocycles, known as thiaarenes, has remained a formidable challenge. This disparity is largely attributed to the sulfur atom's high nucleophilicity and susceptibility to oxidation, which have hindered the single-atom editing of thiaarenes.

Yubing serendipitously discovered a novel photocatalytic strategy that circumvents these challenges and enables the insertion of a boron atom into a diverse range of thiaarenes via boryl radicals. Our approach does not rely on highly reactive intermediates such as carbenes, nitrenes, or carbynes, which are typically the key species involved in known methods. Our method not only furnishes previously inaccessible cyclic thioborane scaffolds but also generates synthetically valuable alkyl boronates in an efficient manner, underscoring its potential to rapidly expand the accessible chemical space from readily available thiaarenes. Moreover, we have also uncovered an unprecedented mechanism for the boron insertion reaction through a combination of mechanistic experiments and DFT calculations. This discovery not only provides insights into the fundamental reactivity of sulfur-containing heterocycles but also offers a blueprint for the development of new catalytic strategies to access organoboron heterocycles. 

For details, please check our manuscript here.