title: Highly efficient palladium precatalysts of homoscorpionate bispyrazolyl ligands for the more challenging Suzuki-Miyaura cross-coupling of aryl chlorides.
abstract: Highly efficient palladium precatalysts {[RN{-(CH(2))(n)-pz(3,5-Me)(2)}(2)]PdCl(2)}(m) [m = n = 1; R = 2,6-Me(2)C(6)H(3) (1), 2,4,6-Me(3)C(6)H(2) (2), CH(2)Ph (3) and m = n = 2; R = CH(2)Ph (4)] of a series of homoscorpionate bispyrazolyl ligands for the Suzuki-Miyaura cross-coupling of the more challenging aryl chloride substrates are reported. In particular, the palladium 1-4 precatalysts carried out the Suzuki-Miyaura cross-coupling of a wide variety of aryl chloride substrates bearing electron withdrawing, electron donating and heteroaryl substituents. Remarkably enough, the molecular structure determination of the 1-4 precatalysts by X-ray diffraction studies revealed the presence of anagostic [C-H...Pd] type interactions in the mononuclear 1-3 complexes of methylene bridged bispyrazolyl ligands whereas the ethylene bridged analog 4 yielded an interesting dimeric 20-membered macrometallacyclic complex devoid of any such interaction.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400 076.
authors.forename: Alex
authors.initials: A
authors.lastname: John
authors.forename: Mobin M
authors.initials: MM
authors.lastname: Shaikh
authors.forename: Ray J
authors.initials: RJ
authors.lastname: Butcher
authors.forename: Prasenjit
authors.initials: P
authors.lastname: Ghosh
mesh_terms: D001593:Benzyl Compounds / Q000737:chemistry*; D002384:Catalysis; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008024:Ligands; D008968:Molecular Conformation; D010165:Palladium / Q000737:chemistry*; D011720:Pyrazoles / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: D001593:Benzyl Compounds; D056831:Coordination Complexes; D008024:Ligands; D011720:Pyrazoles; D010165:Palladium; C021292:benzyl chloride