Aromatic vs aliphatic C-H bond activation by rhodium(I) as a function of agostic interactions: Catalytic H/D exchange between olefins and methanol or water

被引:107
作者
Rybtchinski, B [1 ]
Cohen, R [1 ]
Ben-David, Y [1 ]
Martin, JML [1 ]
Milstein, D [1 ]
机构
[1] Weizmann Inst Sci, Dept Organ Chem, IL-76100 Rehovot, Israel
关键词
D O I
10.1021/ja029197g
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
The aryl-PC type ligand 3, benzyl(di-tert-butyl)phosphane, reacts with [Rh(coe)(2)(solv)(n)]BF4 (coe = cyclooctene, sov = solvent), producing the C-H activated complexes 4a-c (solv (a) acetone, (b) THF, (c) methanol). Complexes 4a-c undergo reversible arene C-H activation (observed by NMR spin saturation transfer experiments, SST) and H/D exchange into the hydride and aryl ortho-H with ROD (R = D, Me). They also promote catalytic H/D exchange into the vinylic C-H bond of olefins, with deuterated methanol or water utilized as D-donors. Unexpectedly, complex 2, based on the benzyl-PC type ligand 1 (analogous to 3), di-tert-butyl(2,4,6-trimethylbenzyl)phosphane, shows a very different reversible C-H activation pattern as observed by SST. It is not active in H/D exchange with ROD and in catalytic H/D exchange with olefins. To clarify our observations regarding C-H activation/reductive elimination in both PC-Rh systems, density functional theory (DFT) calculations were performed. Both nucleophilic (oxidative addition) and electrophilic (H/D exchange) C-H activation proceed through eta(2)-C,H agostic intermediates. In the aryl-PC system the agostic interaction causes C-H bond acidity sufficient for the H/D exchange with water or methanol, which is not the case in the benzyl PC-Rh system. In the latter system the C-H coordination pattern of the methyl controls the reversible C-H oxidative addition leading to energetically different C-H activation processes, in accordance with the experimental observations.
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页码:11041 / 11050
页数:10
相关论文
共 60 条
  • [1] SELECTIVE INTERMOLECULAR CARBON-HYDROGEN BOND ACTIVATION BY SYNTHETIC METAL-COMPLEXES IN HOMOGENEOUS SOLUTION
    ARNDTSEN, BA
    BERGMAN, RG
    MOBLEY, TA
    PETERSON, TH
    [J]. ACCOUNTS OF CHEMICAL RESEARCH, 1995, 28 (03) : 154 - 162
  • [2] Ultrafast UV pump/IR probe studies of C-H activation in linear, cyclic, and aryl hydrocarbons
    Asplund, MC
    Snee, PT
    Yeston, JS
    Wilkens, MJ
    Payne, CK
    Yang, H
    Kotz, KT
    Frei, H
    Bergman, RG
    Harris, CB
    [J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2002, 124 (35) : 10605 - 10612
  • [3] CONTROL OF ETA-2-ARENE COORDINATION AND C-H BOND ACTIVATION BY CYCLOPENTADIENYL COMPLEXES OF RHODIUM
    BELT, ST
    DONG, LZ
    DUCKETT, SB
    JONES, WD
    PARTRIDGE, MG
    PERUTZ, RN
    [J]. JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS, 1991, (04) : 266 - 269
  • [4] ACTIVATION AND ETA-2-COORDINATION OF ARENES - CRYSTAL AND MOLECULAR-STRUCTURE OF AN (ETA-2-HEXAFLUOROBENZENE)RHODIUM COMPLEX
    BELT, ST
    DUCKETT, SB
    HELLIWELL, M
    PERUTZ, RN
    [J]. JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS, 1989, (14) : 928 - 930
  • [5] BROOKHART M, 1988, PROG INORG CHEM, V36, P1
  • [6] CONTROL OF ETA(2)-COORDINATION VS C-H BOND ACTIVATION BY RHODIUM - THE ROLE OF AROMATIC RESONANCE ENERGIES
    CHIN, RM
    DONG, LZ
    DUCKETT, SB
    PARTRIDGE, MG
    JONES, WD
    PERUTZ, RN
    [J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1993, 115 (17) : 7685 - 7695
  • [7] Computational and experimental test of steric influence on agostic interactions: A homologous series for Ir(III)
    Cooper, AC
    Clot, E
    Huffman, JC
    Streib, WE
    Maseras, F
    Eisenstein, O
    Caulton, KG
    [J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1999, 121 (01) : 97 - 106
  • [8] INTER- VS - INTRAMOLECULAR C-H ACTIVATION - A C-H-IR BRIDGE IN [IRH2(8-METHYLQUINOLINE)L2]BF4 AND A C-H + M-]C-M-H REACTION TRAJECTORY
    CRABTREE, RH
    HOLT, EM
    LAVIN, M
    MOREHOUSE, SM
    [J]. INORGANIC CHEMISTRY, 1985, 24 (13) : 1986 - 1992
  • [9] THE ORGANOMETALLIC CHEMISTRY OF ALKANES
    CRABTREE, RH
    [J]. CHEMICAL REVIEWS, 1985, 85 (04) : 245 - 269
  • [10] CRABTREE RH, 1993, ANGEW CHEM INT EDIT, V32, P789, DOI 10.1002/anie.199307891