Zhao Pinjing, Incarvito Christopher D, Hartwig John F
Department of Chemistry, Yale University, PO Box 208107, New Haven, Connecticut 06520-8107, USA.
J Am Chem Soc. 2006 Mar 15;128(10):3124-5. doi: 10.1021/ja058550q.
beta-Aryl eliminations from a series of rhodium(I) alkoxides to form rhodium aryl complexes and free ketones are reported. Tertiary phenylmethoxide complexes [Rh(PEt3)n(OCPhRR')] (n = 2, 3) were prepared via alcoholysis of {Rh(PEt3)2[N(SiMe3)2} by the corresponding alcohols HOCPhRR' in the presence and absence of added PEt3. Heating of these complexes in the presence of added PEt3 generated the rhodium phenyl complex, (PEt3)3RhPh, and the corresponding ketones in good to high yields. Kinetic results are most consistent with irreversible beta-phenyl elimination from a bisphosphine-ligated rhodium alkoxide complex. Such bisphosphine complexes result from ligand dissociation from the trisphosphine complexes and have been isolated in some cases. The bisphosphine complexes are stabilized by Rh-Cphenyl interactions, as evidenced by an X-ray structure, and this structure with a metal-aryl interaction likely illustrates the pathway for C-C bond cleavage.
报道了一系列铑（I）醇盐发生β-芳基消除反应生成铑芳基配合物和游离酮的反应。通过在有和没有添加三乙膦的情况下，相应的醇HOCPhRR'对{Rh(PEt3)2[N(SiMe3)2]}进行醇解反应，制备了叔苯基甲醇盐配合物[Rh(PEt3)n(OCPhRR')]（n = 2, 3）。在添加三乙膦的情况下加热这些配合物，以良好至高收率生成铑苯基配合物(PEt3)3RhPh和相应的酮。动力学结果与双膦配位的铑醇盐配合物发生不可逆的β-苯基消除反应最为一致。此类双膦配合物是由三膦配合物发生配体解离产生的，在某些情况下已被分离出来。如X射线结构所示，双膦配合物通过Rh-C苯基相互作用得以稳定，这种具有金属-芳基相互作用的结构可能阐明了C-C键断裂的途径。
