· (MW 164.82)
(source of nickel(0) useful for the oligomerization of strained alkanes and alkenes,2 and the cyclooligomerization of alkynes3)
Alternate Name: Ni(AN)2.
Physical Data: mp 105 °C dec (N2). The structure of this complex has been thoroughly investigated.4
Solubility: sol pyridine, n-butylamine. Only sparingly sol most other organic solvents.
Analysis of Reagent Purity: IR: nCN 2200, nC=C 1446 cm-1.1
Preparative Methods: under a CO2 condenser, 2.6 g Tetracarbonylnickel (caution: extremely toxic, volatile) was refluxed with 25 mL of freshly distilled Acrylonitrile for 4 h with collection of evolved CO gas. The resultant bright red solid was collected under N2, washed with methanol and ether, and dried.5
Handling, Storage, and Precautions: highly oxygen sensitive: pyrophoric. Special inert-atmosphere techniques must be used.6 Should be stored at 0 °C.
Oligomerization of Strained Alkanes and Alkenes.
Ni(AN)2 has been shown to react with strained alkanes by oxidative addition of nickel(0) to C-C bonds. These organometallic complexes can go on to form new C-C bonds in the presence of electron-deficient alkenes. Bicyclo[2.1.0]pentane reacts with a catalytic amount of Ni(AN)2 in the presence of acrylonitrile or methyl acrylate to give mixtures of norbornane products and a cyclopentene (eq 1).7 The norbornane products are formed by insertion of the activated alkene into the initially formed organometallic complex, followed by reductive elimination of a bridged nickelacyclohexane intermediate. b-Hydride elimination of this intermediate leads instead to the cyclopentene product. Bicyclo[1.1.0]butanes also react
to give allylcyclopropanes (see also Bis(1,5-cyclooctadiene)nickel(0)).8 In addition, the highly-strained 1,8-bishomocubane system has been isomerized in the presence of this catalyst.9
Quadricyclane (1) is isomerized to norbornadiene (3) in the presence of Ni(AN)2 in 87% yield (eq 2).10 The reaction proceeds through organonickel intermediate (2), and indeed, addition of an electron-deficient alkene to pure samples of either (1) or (3) along with the nickel catalyst gives rise to the same adduct (4). This [2 + 2 + 2] cycloaddition of norbornadiene is facilitated by the addition of phosphorus ligands, and the steric properties of these ligands influence the stereoselectivity of the reaction (see also Dicyanobis(triphenylphosphine)nickel(II)).11 Norbornene derivatives can be induced to participate
in [2 + 2] cycloadditions,12 and methylenecyclopropanes react with alkenes to give methylenecyclopentanes (see also Bis(1,5-cyclooctadiene)nickel(0)).13
Cyclooligomerization of Alkynes.
In the presence of a catalytic amount of Ni(AN)2, alkynes can be cyclotrimerized to give benzene derivatives (see also Bis(1,5-cyclooctadiene)nickel(0)).14 Labeling studies have shown that the [2 + 2 + 2] cyclotrimerization of 2-butyne does not take place through a cyclobutadiene intermediate, but probably occurs via a nickelacyclopentadiene species.15 When acetylene is used in this reaction, cyclotetramerization occurs to give cyclooctatetraene (see also Tetrakis(trichlorophosphine)nickel(0)).
This complex can also be used to catalyze the Meerwein arylation reaction16 between activated alkenes and arenediazonium salts.17 Acrylonitrile may be selectively dimerized to form 1,4-dicyanobutenes when phosphorus ligands are present.18 Nitriles are converted into methyl ketones using Ni(AN)2 and Trimethylaluminum.19
- 1. Jolly, P. W.; Wilke, G. The Organic Chemistry of Nickel; Academic: New York, 1974; Vols. I and II.
- 2. (a) Jolly, P. W. In Comprehensive Organometallic Chemistry; Wilkinson, G.; Stone, F. G. A.; Abel, E. W., Eds.; Pergamon: Oxford, 1982; Chapter 56.2, p 615. (b) Binger, P.; Büch, M. Top. Curr. Chem. 1987, 135, 77.
- 3. Jolly, P. W. In Comprehensive Organometallic Chemistry; Wilkinson, G.; Stone, F. G. A.; Abel, E. W., Eds.; Pergamon: Oxford, 1982; Chapter 56.4, p 671.
- 4. (a) Schrauzer, G. N.; Eichler, S. CB 1962, 95, 260. (b) Schrauzer, G. N.; Eichler, S.; Brown, D. A. CB 1962, 95, 2755. (c) Brown, D. A.; Schrauzer, G. N. Z. Phys. Chem. 1963, 36, 1.
- 5. (a) Schrauzer, G. N. JACS 1959, 81, 5310. (b) Schrauzer, G. N. CB 1961, 94, 642.
- 6. Shriver, D. F. The Manipulation of Air-Sensitive Compounds; McGraw-Hill: New York, 1969.
- 7. (a) Noyori, R.; Suzuki, T.; Takaya, H. JACS 1971, 93, 5896. (b) Noyori, R.; Kumagai, Y.; Takaya, H. JACS 1974, 96, 634. (c) Takaya, H.; Suzuki, T.; Kumagai, Y.; Yamakawa, M.; Noyori, R. JOC 1981, 46, 2846.
- 8. (a) Noyori, R.; Suzuki, T.; Kumagai, Y.; Takaya, H. JACS 1971, 93, 5894. (b) Takaya, H.; Suzuki, T.; Kumagai, Y.; Hosoya, M.; Kawauchi, H.; Noyori, R. JOC 1981, 46, 2854.
- 9. Noyori, R.; Yamakawa, M.; Takaya, H. JACS 1976, 98, 1471.
- 10. Noyori, R.; Umeda, I.; Kawauchi, H.; Takaya, H. JACS 1975, 97, 812.
- 11. (a) Schrauzer, G. N.; Eichler, S. CB 1962, 95, 2764. (b) Yoshikawa, S.; Aoki, K.; Kiji, J.; Furukawa, J. BCJ 1975, 48, 3239. (c) Lautens, M.; Edwards, L. G. JOC 1991, 56, 3761 and references therein.
- 12. (a) Yoshikawa, S.; Kiji, J.; Furukawa, J. BCJ 1976, 49, 1093. (b) Takaya, H.; Yamakawa, M.; Noyori, R. BCJ 1982, 55, 852.
- 13. Noyori, R.; Odagi, T.; Takaya, H. JACS 1970, 92, 5780.
- 14. Schrauzer, G. N. CB 1961, 94, 1403.
- 15. Whitesides, G. M.; Ehmann, W. J. JACS 1969, 91, 3800.
- 16. Rondestvedt, C. S., Jr. OR 1976, 24, 225.
- 17. Schrauzer, G. N. CB 1961, 94, 1891.
- 18. Nomura, K.; Ishino, M. J. Mol. Catal. 1991, 68, L5; 1992, 69, L15.
- 19. Bagnell, L.; Jeffery, E. A.; Meisters, A.; Mole, T. AJC 1974, 27, 1577.
Paul A. Wender & Thomas E. Smith
Stanford University, CA, USA
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