Rhodium-catalyzed Dehydroborylation of Styrenes with Naphthalene-1,8-diaminatoborane [(dan)BH]: New Synthesis of Masked β-Borylstyrenes as New Phenylene–Vinylene Cross-coupling Modules

Styrene derivatives underwent dehydroborylation with naphthalene-1,8-diaminatoborane [(dan)BH] in the presence of a cationic rhodium complex, giving β-borylstyrene derivatives in good yields. Thus prepared β-borylstyrenes bearing a chlorine or B(pin) group on their aromatic rings were utilized for the synthesis of highly conjugated molecules through stepwise cross-coupling, taking advantage of the dan group as an effective protective group for a boronyl group.