Light-Mediated Sulfur-Boron Exchange

Interaction of sulfides bearing a tetrafluoropyridinyl group with bis(catecholato)diboron followed by treatment with pinacol and triethylamine affording pinacol boronic esters is described. The reaction is promoted by an organic photocatalyst (3DPA2FBN) under irradiation with 400 nm light, and works with primary, secondary, and tertiary sulfides. The electron depleting character of the fluorinated pyridine fragment plays an important role in generating alkyl radicals.

Automated summary

This study describes the synthesis of pinacol boronic esters through the reaction of sulfides bearing a tetrafluoropyridinyl group with bis(catecholato)diboron, followed by treatment with pinacol and triethylamine. The reaction is promoted by an organic photocatalyst (3DPA2FBN) under irradiation with 400 nm light, and is effective for primary, secondary, and tertiary sulfides. The electron depleting character of the fluorinated pyridine fragment is crucial in generating alkyl radicals.