title: Synthesis and structure of trans-bis(1,4-dimesityl-3-methyl-1,2,3-triazol-5-ylidene)palladium(II) dichloride and diacetate. Suzuki-Miyaura coupling of polybromoarenes with high catalytic turnover efficiencies.
abstract: trans-Bis(1,4-dimesityl-3-methyl-1,2,3-triazol-5-ylidene)palladium(II) dichloride has been shown to be an excellent catalyst for the multiple Suzuki-Miyaura coupling reactions of polybromoarenes to the corresponding fully substituted polyarylarenes. The reactions proceeded in excellent yields and with high turnover numbers. With 1,4-dibromobenzene the catalyst was found to be active for up to 13 consecutive cycles with a turnover number of 1260. The polyarylarenes were obtained in pure form after crystallization once without recourse to chromatographic purification. The single-crystal X-ray structures of the chloro (1) as well as the corresponding acetato (2) complexes are also reported and compared with the corresponding complexes of 1,4-diphenyl-3-methyl-1,2,3-triazol-5-ylidene as the ligand.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
authors.forename: Jeelani Basha
authors.initials: JB
authors.lastname: Shaik
authors.forename: Venkatachalam
authors.initials: V
authors.lastname: Ramkumar
authors.forename: Babu
authors.initials: B
authors.lastname: Varghese
authors.forename: Sethuraman
authors.initials: S
authors.lastname: Sankararaman
keywords: 1,2,3-triazolylidene; C–C coupling; N-heterocyclic carbene; Suzuki–Miyaura coupling; palladium