Highly effective NPN-type tridentate ligands for asymmetric transfer hydrogenation of ketones

Tetrahedron Letters

Volumn 38, Issue 2, 1997, Pages 215-218

  Jiang, Yutong ^a   Jiang, Qiongzhong ^a   Zhu, Guoxin ^a   Zhang, Xumu ^a  

^a PENNSYLVANIA STATE UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ALKANOL;

ARTICLE; CATALYSIS; COMPLEX FORMATION; DRUG SYNTHESIS; REACTION ANALYSIS;

EID: 0031022631     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(96)02257-5     Document Type: Article

References (21)

1. For a review of work done before 1992, see: Zassinovich, G.; Mestroni, G. Chem. Rev. 1992, 92, 1051, and references therein.
2. Cao, J.; Ikariya, T.; Noyori, R. Organometallics 1996, 15, 1087.
3. Hashiguchi, S.; Fujii, A.; Takehara, J.; Ikariya, T.; Noyori, R. J. Am. Chem. Soc. 1995, 117, 7562.
4. Gamez, P.; Fache, F.; Mangeney, P. and Lemaire, M. Tetrahedron Lett. 1993, 34, 6897.
5. (a) Jiang, Q. Z.; Van Plew, D.; Murtuza, S.; Zhang, X. Tetrahedron Lett. 1996,37, 797
6. (b) Evans, D.A.; Nelson, S.G.; Gagné, M.R.; Muci, A.R. J. Am. Chem. Soc. 1993, 115, 9800
7. (c) For a related hydrogenation reaction, see: Sablong, R.; Osborn, J. A. Tetrahedron Lett. 37, 1996, 4937
8. (d) For related hydrosilylation reactions, see: Nishiyama, H.; Kondo, M.; Nakamura, T.; Hoh, K. Organometallics 1991, 10, 500.
9. (a) Langer, T.; Helmchen, G. Tetrahedron Lett. 1996, 37, 1381.
10. (b) von Matt, P.; Pfaltz, A. Angew. Chem., Int. Ed. Engl. 1993, 32, 566.
11. Takehara, J.; Hashiguchi, S.; Fujii, A.; Inoue, S.; Ikariya T.; Noyori, R. J. Chem. Soc., Chem. Commun. 1996, 233.
12. Gamez, P.; Fache, F.; Lemaire, M. Tetrahedron Asymmetry 1995, 6, 705.
13. 3): δ = -6.61.
14. Conversions were up to 94% and ee's up to 31% (S) within 48 h at rt under the general experimental conditions given in note 15.
15. Snider, T.E.; Morris, D.L.; Srivastava, K.C.; Berlin, K.D. Org. Synth., Col. Vol.VI, 932.
16. Bolm, C.; Weickhardt, K.; Zehnder, M. and Ranff, T. Chem. Ber. 1991, 124, 1173.
17. 3): δ = -22.36.
18. 3): δ = -21.99.
19. 2 (5 mg, 0.01 mmol), the ligand solution (0.1 M in toluene, 0.22 mL, 0.022 mmol) and 10 mL of 2-propanol. The mixture was stirred at rt for 1h, followed by addition of base (NaH unless otherwise noted, 7.2 mg, 0.3 mmol) and ketone substrate (2 mmol). The reaction mixture was then stirred at rt or heated at 80°C, after which it was eluted through a silica gel plug with ether and analyzed by GLC to determine product ee and yield.
20. Compared with ligand II in asymmetric transfer hydrogenation of various ketones, ligand III shows much lower enantioselectivity and yields of alcohol products with the opposite absolute configuration (S). Substrate (temp., time, yield %, ee %): acetophenone (80°C, 1 h, 92, 4); pinacolone (rt, 48h, 33, 47); 4-methyl-2-pentanone (rt, 89 h, 93, 8); cyclohexylmethyl ketone (80°C, 1.5 h, 90, 16).
21. Genêt, J. P.; Ratovelomanana-Vidal, V.; Pinel, C. Synlett 1993, 478.