Streamlined Preparation and Coordination Chemistry of Hybrid Phosphine–Phosphaalkene Ligands

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• 作者：Kevin W. Magnuson ; Shelly M. Oshiro ; Joshua R. Gurr ; Wesley Y. Yoshida ; Milan Gembicky ; Arnold L. Rheingold ; Russell P. Hughes ; Matthew F. Cain
• 刊名：Organometallics
• 出版年：2016
• 出版时间：March 28, 2016
• 年：2016
• 卷：35
• 期：6
• 页码：855-859
• 全文大小：381K
• ISSN：1520-6041

文摘

A rationally designed and selective synthesis of hybrid phosphine–phosphaalkene ligands E-1a (Cy₂PCH₂CH═PMes*, Mes* = 2,4,6-tri-tert-butylphenyl) and E-1b (Ph₂PCH₂CH═PMes*) was developed using phospha-Wittig methodology. The new hybrid ligands E-1a and E-1b were used to prepare the Pd and Pt dichloride complexes Pd(Cy₂PCH₂CH═PMes*)Cl₂ (2a), Pd(Ph₂PCH₂CH═PMes*)Cl₂ (2b), Pt(Cy₂PCH₂CH═PMes*)Cl₂ (3a), and Pt(Ph₂PCH₂CH═PMes*)Cl₂ (3b). The crystal structures of E-1a, E-1b, 2a·1.33CHCl₃, 3a·CH₃CN, and 3b were determined. DFT calculations (M06/LACV3P**) on 2a revealed that the π* orbital located on the P═C unit is low-lying and accessible. An NBO analysis concluded that the phosphaalkene ligand is a significantly poorer σ donor and a slightly better π acceptor than its tertiary phosphine counterpart, due to the presence of the P═C double bond.