Palladium complexes of 8-(di-tert

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• 作者：Bruno Crociani ; Simonetta Antonaroli ; Marcello Burattini ; Franco Benetollo ; Alberto Scrivanti ; Matteo Bertoldini
• 关键词：Palladium organometallic complexes ; Phosphinito– ; quinoline ligands ; Solution and solid state structure ; Suzuki– ; Miyaura reaction
• 刊名：Journal of Organometallic Chemistry
• 出版年：2008
• 出版时间：15 December 2008
• 年：2008
• 卷：693
• 期：26
• 页码：3932-3938
• 全文大小：407 K

文摘

The preparation of the new ligand 8-(di-tert-butylphosphinooxy)quinoline (1) and the palladium derivatives [PdCl₂(1)] (2), [Pd(η³-all)(1)]⁺ [all = C₃H₅ (3a), 1-PhC₃H₄ (3b) and 1,3-Ph₂C₃H₃ (3c)] and [Pd(η²-ol)(1)] [ol = dimethyl fumarate (4a) and fumaronitrile (4b)] is reported. The cationic species 3a–3c have been isolated as salts. The complex 3a(BF₄) is obtained either from the reaction of 1 with [Pd(μ-Cl)(η³-C₃H₅)]₂ or from the reaction of ClP(CMe₃)₂ with [Pd(η³-C₃H₅)(8-oxyquinoline)], followed in both cases by chloride abstraction with NaBF₄. In the complexes, the ligand 1 is P,N chelated to the central metal, as shown by the X-ray structural analysis of 3a(BF₄). At 25 °C in solution, 3a(BF₄) and 3b(BF₄) undergo a fast η³−η¹−η³ dynamic process which brings about a syn–anti exchange only for the allylic protons cis to phosphorus, while for 4a and 4b a slow rotation of the olefin around its bond axis to palladium takes place. The complexes 2 and 3a(BF₄) are efficient catalyst precursors in the coupling of the phenylboronic acid with aryl bromides and chlorides.