Motswainyana W.M., Onani M.O., Lalancette R.A., Tarus P.K.
Hemilabile imino-phosphine palladium(II) complexes: Synthesis, molecular structure, and evaluation in Heck reactions
Chemistry Department, University of the Western Cape, Private Bag X17, 7535 Bellville, South Africa; Carl A. Olson Memorial Laboratories, Department of Chemistry, Rutgers University, Newark, NJ 07102, United States; Department of Chemistry and Biochemistry, University of Eldoret, P.O. Box 1125-30100, Eldoret, Kenya
Motswainyana, W.M., Chemistry Department, University of the Western Cape, Private Bag X17, 7535 Bellville, South Africa; Onani, M.O., Chemistry Department, University of the Western Cape, Private Bag X17, 7535 Bellville, South Africa; Lalancette, R.A., Carl A. Olson Memorial Laboratories, Department of Chemistry, Rutgers University, Newark, NJ 07102, United States; Tarus, P.K., Department of Chemistry and Biochemistry, University of Eldoret, P.O. Box 1125-30100, Eldoret, Kenya
The ligands 2-(diphenylphosphino)benzyl-(2-thiophene)methylimine (V) and 2-(diphenylphosphino) benzyl-(2-thiophene)ethylimine (VI) were prepared from 2-(diphenylphosphino)benzaldehyde and thiophene amines with very good yields. An equimolar reaction of V and VI with either PdCl2(cod) (cod = cyclooctadiene) or PdClMe(cod) afforded palladium(II) complexes I-IV. The molecular structure of II was confirmed by X-ray crystallography. The coordination geometry around the palladium atom exhibited distorted square planar geometry at the palladium centre. Complexes I, II, and IV were evaluated as catalysts for Heck coupling reactions of iodobenzene with methyl acrylate under mild reaction conditions; 0.1 mole % catalyst, Et3N base, MeCN reflux for 8 h, 80 C; isolated yield on a 10 mmol scale with catalyst I (64 %), II (68 %), and IV (58 %). They all exhibited significant activities. © 2013 Institute of Chemistry, Slovak Academy of Sciences.