메뉴 건너뛰기




Volumn , Issue 11, 2007, Pages 1576-1584

Nickel(II)-carbene intermediates in reactions of geminal dihaloalkanes with nickel(0) reagents and the corresponding carbene capture as the phosphonium ylide

Author keywords

Carbon carbon bond formation; Nickel(0) reagents; Nickel(II) carbenes; Phosphonium ylides; elimination

Indexed keywords

CARBON; CRYSTAL STRUCTURE; NICKEL COMPOUNDS; ORGANOMETALLICS; REACTION INTERMEDIATES;

EID: 34347256435     PISSN: 14341948     EISSN: 10990682     Source Type: Journal    
DOI: 10.1002/ejic.200601106     Document Type: Article
Times cited : (11)

References (35)
  • 9
    • 85153323478 scopus 로고    scopus 로고
    • 13C NMR evidence justifying the ylide resonance structure 22c as the paramount contributor to the π-electron distribution of this molecule:
    • 13C NMR evidence justifying the ylide resonance structure 22c as the paramount contributor to the π-electron distribution of this molecule:
  • 12
    • 85153255187 scopus 로고    scopus 로고
    • the preparative procedure for 21 has been developed in this laboratory and is published here for the first time.
    • b) the preparative procedure for 21 has been developed in this laboratory and is published here for the first time.
  • 15
    • 85153203663 scopus 로고    scopus 로고
    • [11a], such percentages for 24 ranged from 20% to 80%, depending upon the method of calculation.
    • [11a], such percentages for 24 ranged from 20% to 80%, depending upon the method of calculation.
  • 16
    • 85153319580 scopus 로고    scopus 로고
    • S. Neander, F. E. Tio, R. Buschman, U. Behrens, F. Olbrich, J. Organomet. Chem. 1999, 582, 58-65. For the potassium (18-crown-6) salt the C-C bonds range from 1.371-1.411 Å.
    • S. Neander, F. E. Tio, R. Buschman, U. Behrens, F. Olbrich, J. Organomet. Chem. 1999, 582, 58-65. For the potassium (18-crown-6) salt the C-C bonds range from 1.371-1.411 Å.
  • 18
    • 85153255362 scopus 로고    scopus 로고
    • 13C NMR signals) of the aromatic carbon atom directly attached to the substituent have been correlated with substituent electronegativity after correcting for magnetic anisotropy effects. On the Allred-Rochow scale phosphorus at 2.06 is electron-releasing relative to carbon at 2.50 and thus magnetically shielding towards carbon.
    • 13C NMR signals) of the aromatic carbon atom directly attached to the substituent have been correlated with substituent electronegativity after correcting for magnetic anisotropy effects". On the Allred-Rochow scale phosphorus at 2.06 is electron-releasing relative to carbon at 2.50 and thus magnetically shielding towards carbon.
  • 19
    • 85153173590 scopus 로고    scopus 로고
    • A referee has been helpful in suggesting the possibility of path b as an alternative possibility for producing 22c from 19 and 20 without the intermediacy of a nickel(II)-carbene. In addition, the same referee suggested the key experiment for deciding on the viability of path b as a competing mechanism, namely whether or not 19 and 20a would react with each other at 25°C
    • A referee has been helpful in suggesting the possibility of path b as an alternative possibility for producing 22c from 19 and 20 without the intermediacy of a nickel(II)-carbene. In addition, the same referee suggested the key experiment for deciding on the viability of path b as a competing mechanism, namely whether or not 19 and 20a would react with each other at 25°C.
  • 21
    • 85153240537 scopus 로고    scopus 로고
    • Although this report appeared 50 years ago, it has not been repudiated since and in fact is treated as reliable in a classic monograph on organophosphorus reactions: R. F. Hudson, Structure and Mechanism in Organo-Phosphorus Chemistry, Academic Press, New York, 1965, pp. 297-299
    • b) Although this report appeared 50 years ago, it has not been repudiated since and in fact is treated as reliable in a classic monograph on organophosphorus reactions: R. F. Hudson, Structure and Mechanism in Organo-Phosphorus Chemistry, Academic Press, New York, 1965, pp. 297-299.
  • 22
    • 85153235442 scopus 로고    scopus 로고
    • When the THF solution of the final reaction mixture was concentrated to half its and then cooled to 0°C, dark red crystals of bis(triethylphosphane)nickel(II) chloride were deposited, mp. 113-115°C 68, D. T. Doughty, G. Gordon, R. P. Stewart Jr, J. Am. Chem. Soc. 1979, 101, 2645-2648
    • When the THF solution of the final reaction mixture was concentrated to half its volume and then cooled to 0°C, dark red crystals of bis(triethylphosphane)nickel(II) chloride were deposited, mp. 113-115°C (68%); D. T. Doughty, G. Gordon, R. P. Stewart Jr, J. Am. Chem. Soc. 1979, 101, 2645-2648.
  • 23
    • 85153308272 scopus 로고    scopus 로고
    • A referee has proposed that in such coupling reactions of geminal dihalides with (Et3P)4Ni (20) perhaps metal carbenes are not involved at all, that maybe they are just phosphonium ylide adducts, R3P+-CR2--NiCl2 and, as Milstein and co-workers have shown, that ylides could be converted to metal-carbenes by late transition metal compounds (M. Gandelman, K. M. Naing, B. Rybtchinski, E. Poverenov, Y. Ben-David, N. Ashkenazi, R. M. Gauvin, D. Milstein, J. Am. Chem. Soc. 2005, 127, 15265-15272, Admittedly, our work has shown that phosphonium ylide 22c is readily formed from dibromo compound 19 and (Et3P)4Ni (20) and that 30 and 20 produce Wittig reagent 37 in solution, which is capable of being captured in a Wittig reaction with benzophenone. Despite the presence of 37 in such reactions, such phosphonium ylides or th
    • 3P): (Chemical Equation Presented)
  • 24
    • 85153179682 scopus 로고    scopus 로고
    • 4-tetraphenylcyclobutadiene-nickel(II) bromide where the two units of the monomer are held together by two Ni⋯Br⋯Ni bridges.
    • 4-tetraphenylcyclobutadiene-nickel(II) bromide where the two units of the monomer are held together by two Ni⋯Br⋯Ni bridges.
  • 25
    • 85153187145 scopus 로고    scopus 로고
    • The failure to detect triphenylethylene in this trapping experiment with benzaldehyde can stem from either of two causes: (1) the supposed ylide, Ph 2C=PEt2, is too slow to react with PhCHO, before it reacts thus: Ph2C=PEt3, Ph2C(Cl)NiCl → Ph 2C=CPh2, Et3P)2NiCl2; or (2) in analogy with Scheme 7, Et3P is unable, for steric reasons, to react with Ph2C-NiCl2 (36) before coupling occurs via 38
    • 2 (36) before coupling occurs via 38.
  • 26
    • 85153220104 scopus 로고
    • 3) and the mass spectrum of the mixture: MS (70eV): m/z = 270 [M], 179, 178, 152, 89, 77, Masters Thesis, SUNY-Binghamton
    • 3) and the mass spectrum of the mixture: MS (70eV): m/z = 270 [M], 179, 178, 152, 89, 77 (Y. Qian, Masters Thesis, SUNY-Binghamton, 1992, p. 57;
    • (1992) , pp. 57
    • Qian, Y.1
  • 27
    • 85153285280 scopus 로고    scopus 로고
    • Y. Qian, Research Notebook No. 1, May 22, 1991, p. 36.
    • Y. Qian, Research Notebook No. 1, May 22, 1991, p. 36).
  • 28
    • 85153245167 scopus 로고    scopus 로고
    • [7]; Y. Qian, Doctoral Dissertation, SUNY-Binghamton, 1996, pp. 117-118;
    • [7]; Y. Qian, Doctoral Dissertation, SUNY-Binghamton, 1996, pp. 117-118;
  • 29
    • 85153229636 scopus 로고    scopus 로고
    • Y. Qian, Research Notebook No. 1, October 19, 1991, p. 66. The detailed mechanisms of these carbenoid oligomerizations are under further investigation.
    • Y. Qian, Research Notebook No. 1, October 19, 1991, p. 66). The detailed mechanisms of these carbenoid oligomerizations are under further investigation.
  • 30
    • 0012006921 scopus 로고
    • Academic Press, New York
    • J. J. Eisch, Organometallic Syntheses, Academic Press, New York, 1981, vol. 2, pp. 1-84.
    • (1981) Organometallic Syntheses , vol.2 , pp. 1-84
    • Eisch, J.J.1


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.