Theoretical study of reaction pathways for the rhodium phosphine-catalysed borylation of C-H bonds with pinacolborane

被引:94
作者
Lam, WH
Lam, KC
Lin, ZY
Shimada, S
Perutz, RN
Marder, TB
机构
[1] Hong Kong Univ Sci & Technol, Dept Chem, Kowloon, Hong Kong, Peoples R China
[2] Hong Kong Univ Sci & Technol, Inst Mol Technol Drug Discovery & Synth, Open Lab Chirotechnol, Kowloon, Hong Kong, Peoples R China
[3] Natl Inst Adv Ind Sci & Technol, Tsukuba, Ibaraki 3058565, Japan
[4] Univ Durham, Dept Chem, Durham DH1 3LE, England
[5] Univ York, Dept Chem, York YO10 5DD, N Yorkshire, England
关键词
D O I
10.1039/b402632b
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
The reaction mechanism of the rhodium - phosphine catalysed borylation of methyl-substituted arenes using pinacolborane (HBpin) has been investigated theoretically using DFT calculations at the B3PW91 level. Factors affecting selectivity for benzylic vs. aromatic C - H bond activation have been examined. It was found that [Rh(PR3)(2)(H)] is the active species which oxidatively adds the C - H bond leading to an eta(3)-benzyl complex which is the key to determining the unusual benzylic regioselectivity observed experimentally for this catalyst system. Subsequent reaction with HBpin leads to a [Rh(PR3)(2)(eta(3)-benzyl)(H)(Bpin)] complex from which B - C reductive elimination provides product and regenerates the catalyst. The electrophilic nature of the boryl ligand assists in the reductive elimination process. In contrast to Ir(L)(2)(boryl)(3)-based catalysts, for which Ir(III) - Ir(V) cycles have been proposed, the Rh(I) - Rh(III) cycle is operating with the system addressed herein.
引用
收藏
页码:1556 / 1562
页数:7
相关论文
共 47 条
  • [1] CARBON-HETEROATOM BOND-FORMING REDUCTIVE ELIMINATION - MECHANISM, IMPORTANCE OF TRAPPING REAGENTS, AND UNUSUAL ELECTRONIC EFFECTS DURING FORMATION OF ARYL SULFIDES
    BARANANO, D
    HARTWIG, JF
    [J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1995, 117 (10) : 2937 - 2938
  • [2] C-H bond activation of benzene and methane by M(η2-O2CH)2 (M = Pd or Pt).: A theoretical study
    Biswas, B
    Sugimoto, M
    Sakaki, S
    [J]. ORGANOMETALLICS, 2000, 19 (19) : 3895 - 3908
  • [3] Burke K., 1998, ELECT DENSITY FUNCTI
  • [4] Chen HY, 1999, ANGEW CHEM INT EDIT, V38, P3391, DOI 10.1002/(SICI)1521-3773(19991115)38:22<3391::AID-ANIE3391>3.0.CO
  • [5] 2-N
  • [6] Thermal, catalytic, regiospecific functionalization of alkanes
    Chen, HY
    Schlecht, S
    Semple, TC
    Hartwig, JF
    [J]. SCIENCE, 2000, 287 (5460) : 1995 - 1997
  • [7] Remarkably selective iridium catalysts for the elaboration of aromatic C-H bonds
    Cho, JY
    Tse, MK
    Holmes, D
    Maleczka, RE
    Smith, MR
    [J]. SCIENCE, 2002, 295 (5553) : 305 - 308
  • [8] Steric and chelate directing effects in aromatic borylation
    Cho, JY
    Iverson, CN
    Smith, MR
    [J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2000, 122 (51) : 12868 - 12869
  • [9] Structural studies of bis-catecholate, bis-dithiocatecholate, and tetraalkoxy diborane(4) compounds
    Clegg, W
    Elsegood, MRJ
    Lawlor, FJ
    Norman, NC
    Pickett, NL
    Robins, EG
    Scott, AJ
    Nguyen, P
    Taylor, NJ
    Marder, TB
    [J]. INORGANIC CHEMISTRY, 1998, 37 (20) : 5289 - 5293
  • [10] Rhodium catalysed dehydrogenative borylation of vinylarenes and 1,1-disubstituted alkenes without sacrificial hydrogenation - a route to 1,1-disubstituted vinylboronates
    Coapes, RB
    Souza, FES
    Thomas, RL
    Hall, JJ
    Marder, TB
    [J]. CHEMICAL COMMUNICATIONS, 2003, (05) : 614 - 615