Organoboron compounds have become important intermediates for the construction of new compounds in synthetic chemistry and pharmaceutical chemistry, and it has been found that pinacol biborate (B₂pin₂) as the boron source and Cu^II organophosphorus complex (L) as the catalyst can effectively realize the hydrogen-reduced borylation products and dehydrohydrated borylation products of aryl olefins. The reaction regioselectivity involving β-C positions of aryl olefins can be controlled by regulating the ligand and additive types. The formation mechanism of the product is conducted at LCu^IBpin formed from Cu^II, L and B₂pin₂. Subsequently the substrate aryl olefins undergo addition reaction to form the active intermediate PhCH(LCu^I)CH₂Bpin. Followed by the metathesis of the active intermediate with water to form hydrogen reduction products, the same active intermediate can be oxidized with 2,2,6,6-tetramethylpiperidoxyl (TEMPO) to form trans dehydrogenation products.

Key words: arylenes, bis(pinacolato)diboron, copper organic phosphine complex, hydrogenative borylation reduction, boron dehydrogenation oxidation