A new Pd(II) complex of a sulfur ylide; Synthesis, X-ray characterization, theoretical study and catalytic activity toward the Suzuki–Miyaura reaction. (15th October 2016)

• Record Type: Journal Article
• Authors: Sabounchei, S.J.; Yousefi, A.; Ahmadianpoor, M.; Hashemi, A.; Bayat, M.; Sedghi, A.; Bagherjeri, F.A.; Gable, R.W.
• Is Part Of: Polyhedron. Volume 117(2016)
• Page Start: 273
• Page End: 282
• Publication Date: 2016-10-15
• Subjects: Sulfur ylide -- Palladium(II) complex -- X-ray characterization -- Suzuki–Miyaura reaction -- Theoretical study; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2016.05.046
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: The new sulfonium salt [SMe2 CH2 C(O)C6 H4 - m -OCH3 ]Br (1 ) was synthesized from the reaction of dimethyl sulfide and 2-bromo-3′-methoxyacetophenone. Further treatment with NaOH 10% gave the α-keto stabilized sulfur ylide SMe2 C(H)C(O)C6 H4 - m -OCH3 (2 ). This ligand was reacted with the dichloro(1, 5-cyclooctadiene)palladium(II) complex, [PdCl2 (cod)], in a 2:1 ratio to give the new Cα-coordinated complexes cis - and trans -[PdCl2 (SMe2 C(H)C(O)C6 H4 - m -OCH3 )2 ] (3a and3b ). The X-ray analysis results revealed that complex3a has undergone a ligand replacement reaction in DMSO solution and the complex [PdCl2 (SMe2 C(H)C(O)C6 H4 - m -OCH3 )·DMSO] (4 ) was formed. The air/moisture stable complexes3a and3b were employed as efficient catalysts for the Suzuki–Miyaura cross-coupling reaction of several aryl halides. Also a theoretical study on the structure and nature of the Pd–C bond in complex4 is reported here at the BP86/def2-SVP level of theory. Abstract: The new sulfonium salt [SMe2 CH2 C(O)C6 H4 - m -OCH3 ]Br (1 ) was synthesized from the reaction of dimethyl sulfide and 2-bromo-3′-methoxyacetophenone. Further treatment with NaOH 10% gave the α-keto stabilized sulfur ylide SMe2 C(H)C(O)C6 H4 - m -OCH3 (2 ). This ligand was reacted with the dichloro(1, 5-cyclooctadiene)palladium(II) complex, [PdCl2 (cod)], in a 2:1 ratio to give the new Cα-coordinated complexes cis - and trans -[PdCl2 (SMe2 C(H)C(O)C6 H4 - m -OCH3 )2 ] (3a and3b ). Characterization of the obtained compounds was performed by elemental analysis, IR, 1 H, 13 C NMR and mass spectroscopies. Since complexes3a and3b were insoluble in most organic solvents, we chose DMSO as a suitable solvent for the NMR spectroscopies. Crystallization of above solution led to the formation of single crystals. The X-ray analysis results revealed that complex3a has undergone a ligand replacement reaction and the complex [PdCl2 (SMe2 C(H)C(O)C6 H4 - m -OCH3 )·DMSO] (4 ) was formed. This complex has two Cl atoms in cis positions, one sulfur ylide and one S-coordinated DMSO as ligands. The air/moisture stable complexes3a and3b were employed as efficient catalysts for the Suzuki–Miyaura cross-coupling reaction of several aryl halides. The coupled products of these reactions were obtained in good to excellent yields and purity, with short reaction times and low catalyst loading. Also a theoretical study on the structure and nature of the Pd–C bond in complex4 is reported here at the BP86/def2-SVP level of theory.