A concise and effective three-step synthesis of 4a,8a-azaboranaphthalene (ABN) has been developed in gram scale. Electrophilic aromatic substitution reactions of ABN provide excellent functional-group-tolerant cross-coupling partners in various Pd-catalyzed cross-coupling reactions (e.g., Sonogashira, Suzuki-Miyaura, or Heck reaction). Photophysical, electrochemical, and DFT calculations all suggest a narrowed HOMO-LUMO gap with extended π-conjugation characters in the cross-coupled molecules. The ABN moiety as a new fluorophore has a distinct and selective fluorescence response toward Zn(II) and Cd(II) ions, demonstrating great potential for the ABN structural motif in fluorescent chemosensors.

The acylation reaction of BN-arenes has been studied using BN-arene and acyl chloride in good to excellent yields, which led to the first synthesis of indanone BN-analogue. The BN-aromatic ketone products have been characterized by H NMR spectroscopy with their molecular structures unambiguously confirmed by X-ray crystallography. The annulation reaction of BN-arenes promoted by AgBF occurs in a completely regioselective manner and a mechanism for this transformation is proposed.

Design, synthesis and characterization of new BN-aromatic phosphine ligands are presented, demonstrating moderate catalytic activity in Suzuki reactions of C–Cl bond.