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Volumn 126, Issue 36, 2004, Pages 11268-11278

Mechanistic characterization of aerobic alcohol oxidation catalyzed by Pd(OAc)2/pyridine including identification of the catalyst resting state and the origin of nonlinear [catalyst] dependence

Author keywords

[No Author keywords available]

Indexed keywords

ALCOHOLS; CATALYSIS; KINETIC THEORY; NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY; OXIDATION; PROTONS; SUBSTRATES;

EID: 4544248275     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja049962m     Document Type: Article
Times cited : (200)

References (96)
  • 4
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    • Ricci, A., Ed.; Wiley-VCH: New York
    • (c) Hartwig, J. F. In Modern Amination Methods; Ricci, A., Ed.; Wiley-VCH: New York, 2000; pp 195-262.
    • (2000) Modern Amination Methods , pp. 195-262
    • Hartwig, J.F.1
  • 37
    • 4544308265 scopus 로고    scopus 로고
    • note
    • For a preliminary report on the kinetics of this catalyst system, see ref 8c.
  • 38
    • 4544381365 scopus 로고    scopus 로고
    • note
    • D = 1.6(2), 1.4(2), and 1.6(2) at [alcohol] = 0.05, 0.10, and 1.0 M, respectively. The latter two values fall within the uncertainty of the originally reported KIEs, but inclusion of the 0.05 M data forces us to conclude that the KIE does not depend on [alcohol].
  • 39
    • 0010535169 scopus 로고
    • For previous characterization of related structures, see: (a) Nahringbauer, I. Acta Chem. Scand. 1969, 23, 1653-1666.
    • (1969) Acta Chem. Scand. , vol.23 , pp. 1653-1666
    • Nahringbauer, I.1
  • 46
    • 4544261941 scopus 로고    scopus 로고
    • note
    • Small differences between the chemical shifts of 3 and 4, prepared independently, and those observed under catalytic conditions suggest that a rapidly equilibrating interaction also exists between the alcohol substrate and complexes 3 and 4.
  • 50
    • 4544242370 scopus 로고    scopus 로고
    • note
    • 2OH), but such evidence was not obtained, even at low temperatures. Such distinctions may not be evident, however, if the adduct is highly fluxional in the presence of a large excess of substrate.
  • 51
    • 4544370754 scopus 로고    scopus 로고
    • note
    • For recent studies and leading references on five-coordinate palladium(II) complexes, see:
  • 57
    • 4544386455 scopus 로고    scopus 로고
    • unpublished results
    • 3)(OAc) + AcOH. The optimized structures were verified to be at a local minimum by calculation of the harmonic vibrational frequencies. Attempts to locate a stable five-coordinate palladium structures analogous to 9 and 10 have been unsuccessful. In each case, the optimization routine yields a minimum energy structure that possesses a hydrogen bond between the alcohol O-H and the carbonyl oxygen of a coordinated acetate ligand. The alcohol oxygen is oriented over the axial coordination site, but lies at a nonbonding distance of 3.6 Å. Relaxed potential energy surface (RPES) scans have also been conducted to probe the reaction pathway. The scans are conducted in the reverse (energetically favorable) direction by using optimized geometries of the square planar palladium-methoxide intermediate and acetic acid. The carbonyl oxygen of the acetic acid is directed over the axial coordination site of Pd, and the proton of the acid is directed over the oxygen of the methoxide ligand. Initial scans produce a product structure that closely resembles the optimized, hydrogen-bonded, alcohol adduct described above, which possesses no formal palladium-oxygen interaction. The transition state in this pathway has a trigonal bipyramidal structure in which the trigonal plane consists of two monodentate acetate ligands and an oxygen-bound alcohol ligand.
    • Popp, B.V.1    Landis, C.R.2    Stahl, S.S.3
  • 66
    • 4544383645 scopus 로고    scopus 로고
    • note
    • 2, is also consistent with the experimental results.
  • 67
    • 4544243308 scopus 로고    scopus 로고
    • note
    • 2 exhibits a background rate in the absence of exogenous base (ref 10b). Morever, they have recently reported a crystal structure of a palladium complex with acetate and water ligands in which the acetate engages in a six-membered ring intramolecular hydrogen bond (ref 10c).
  • 85
    • 4544273446 scopus 로고    scopus 로고
    • note
    • 2OH, 7. and 8) prior to rate-limiting β-hydride elimination were unsuccessful.
  • 86
    • 4544261940 scopus 로고    scopus 로고
    • ref 2b
    • This goal has been especially evident in the development of palladium-catalyzed cross-coupling reactions. See. for example: (a) ref 2b.
  • 87
    • 0037112673 scopus 로고    scopus 로고
    • This goal has been especially evident in the development of palladium-catalyzed cross-coupling reactions. See. for example: (a) ref 2b. (b) Littke, A. F.; Fu, G. C. Angew. Chem., Int. Ed. 2002, 41, 4176-4211.
    • (2002) Angew. Chem., Int. Ed. , vol.41 , pp. 4176-4211
    • Littke, A.F.1    Fu, G.C.2
  • 88
    • 4544284864 scopus 로고    scopus 로고
    • note
    • Linear [catalyst] dependence has also been observed. See ref 10.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.