Ni(COD)2/4-ClC6H4COR-catalyzed addition reactions of arylboroxines with aldehydes

Ni(COD)2/4-ClC6H4COR (R = H, CH3, Ph) was found to be an efficient catalyst system for the addition reactions of arylboroxines with aromatic and aliphatic aldehydes. The catalytically active species for Ni(COD)2/4-ClC6H4COR catalyst systems was likely to be their oxidative addition adducts, 4-RCOC6H4Ni(II)Cl(COD) complexes.