Synthesis of B-Protected β-Styrylboronic Acids via Iridium-Catalyzed Hydroboration of Alkynes with 1,8-Naphthalenediaminatoborane Leading to Iterative Synthesis of Oligo(phenylenevinylene)s

Hydroboration of aromatic and aliphatic alkynes with 1,8-naphthalenediaminatoborane ((dan)BH) proceeded in the presence of [IrCl(cod)](2) complex with a DPPM or DPEphos ligand, affording alkenylboronic acids whose boronyl groups are masked by the diaminonaphthalene group. The masked alkenylboronic acids thus obtained from alkynes bearing halo-substituted aryl groups served as new coupling modules in an iterative Suzuki-Miyaura cross-coupling reaction for the synthesis of oligo(phenylenevinylene)s.