메뉴 건너뛰기




Volumn 34, Issue 8, 1995, Pages 931-933

Strong Electronic Effects on Enantioselectivity in Rhodium‐Catalyzed Hydroborations with Novel Pyrazole‐Containing Ferrocenyl Ligands

Author keywords

asymmetric syntheses; complexes with P,N ligands; ferrocenyl ligands; hydroborations

Indexed keywords


EID: 33748511263     PISSN: 05700833     EISSN: 15213773     Source Type: Journal    
DOI: 10.1002/anie.199509311     Document Type: Article
Times cited : (177)

References (36)
  • 4
    • 0000146695 scopus 로고
    • Chirale Phosphinoaryldihydrooxazole als Liganden in der asymmetrischen Katalyse: Pd-katalysierte allylische Substitution
    • (a) For other successful chiral P,N‐ligands recently reported, see
    • (1993) Angewandte Chemie , vol.105 , pp. 614-615
    • von Matt, P.1    Pfaltz, A.2
  • 13
    • 0000535353 scopus 로고
    • Stickstoffdonoren in der Organometallchemie und in der Homogenkatalyse
    • For a review on nitrogen ligands in homogeneous catalysis, see
    • (1994) Angewandte Chemie , vol.106 , pp. 517-547
    • Togni, A.1    Venanzi, L.M.2
  • 17
    • 84987539502 scopus 로고
    • (a) Electronic effects in asymmetric catalysis with other types of ligands have been recently reported. Rh‐catalyzed hydrogenation:, Synlett
    • (1992) , pp. 169-178
    • Inoguchi, K.1    Sakuraba, S.2    Achiwa, K.3
  • 26
  • 31
    • 84985523869 scopus 로고
    • 95–158. The cone angle of a methyl group is 112°, whereas that of the trifluoromethyl substituent is 135°, identical to the value for isopropyl.
    • (1994) Adv. Organomet. Chem. , vol.36
    • White, D.1    Coville, N.J.2
  • 32
    • 84985583288 scopus 로고    scopus 로고
    • Substrate electronic effects were also observed (see also [4]). Thus, compared to styrene and in the presence of ligand 2a, para‐chlorostyrene and para‐methoxystyrene both gave lower ee's (93.5 and 79.2% ee, respectively). With ligand 2b the same two substrates afforded 13 and 77.6% ee, compared to 33.4% ee for styrene.
  • 33
    • 84985595410 scopus 로고    scopus 로고
    • Assuming a conservative NMR detection limit of 100:1 for two different compounds, such a difference in stability constant between the complexes containing 2g and 2b is inferred by comparing different pairs of ligands. These stability measurements, carried out on catalyst precursors, do not necessarily reflect the stabilities of the actual complexes involved in the catalytic cycle, but may be reasonably taken as an indication of the trend.
  • 34
    • 84985500997 scopus 로고    scopus 로고
    • However, the existence of a catalytically active complex containing the ferrocenyl ligand acting in a monodentate fashion under kinetic control cannot be excluded by these experiments.
  • 35
    • 85021603819 scopus 로고
    • (a) For general discussions of electronic effects in organic chemistry see, for example, 4th ed., Wiley, New York, Chapter 9, pp.
    • (1992) Advanced Organic Chemistry , pp. 273-292
    • March, J.1


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.