Highly Selective Asymmetric Hydrogenation Using a Three Hindered Quadrant Bisphosphine Rhodium Catalyst

Journal of the American Chemical Society

Volumn 126, Issue 19, 2004, Pages 5966-5967

  Hoge, Garrett ^a   Wu, He Ping ^a   Kissel, William S ^a   Pflum, Derek A ^a   Greene, Derek J ^a   Bao, Jian ^a  

^a PFIZER INC   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

PHOSPHINE DERIVATIVE; PREGABALIN; RHODIUM COMPLEX;

ARTICLE; ASYMMETRIC CATALYSIS; CATALYST; CHIRALITY; COMPLEX FORMATION; ENANTIOSELECTIVITY; HYDROGENATION; PROTON TRANSPORT;

EID: 2442618362     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja048496y     Document Type: Article

References (16)

1. Reviews: (a) Tang, W.; Zhang, X. Chem. Rev. 2003, 103, 3029.
2. (b) Ohkuma, T.; Kitamura, M.; Noyori, R. In Catalytic Asymmetric Synthesis, 2nd ed.; Ojima, I., Ed.; Wiley-VCH: New York, 2000; pp 1-110.
3. (c) Brown, J. M. In Comprehensive Asymmetric Catalysis; Jacobsen, E. N., Pfalz, A., Yamamoto, H., Eds.; Springer-Verlag: Berlin, 1999; Vol. I, pp 121-182.
4. An excellent example is the development of an extraordinary number of phospholane ligands, all of which are based on the DuPhos structure. For a discussion on this topic, see: Hoge, G. J. Am. Chem. Soc. 2003, 125, 10219.
5. Imamoto, T.; Watanabe, J.; Wada, Y.; Masuda, H.; Yamada, H.; Tsuruta, H. ; Matsukawa, S.; Yamaguchi, K. J. Am. Chem. Soc. 1998, 120, 1635.
6. 1-symmetrical ligands with respect to steric environments of the ligands and their corresponding catalysts that translate to high enantioselectivity during hydrogenation. See: (a) Blaser, H.; Brieden, W.; Pugin, B.; Spindler, F.; Studer, M.; Togni, A. Top. Catal. 2002, 19, 3.
7. (b) Ohashi, A.; Kikuchi, S.; Yasutake, M.; Imamoto, T. Eur. J. Org. Chem. 2002, 15, 2535.
8. (c) Matsumura, K.; Shimizu, H.; Saito, T.; Kumobayashi, H. Adv. Synth. Catal. 2003, 345, 180.
9. Ligand 2 is referred to as "Trichickenfootphos" in Pfizer laboratories. This name is derived from visual inspection of the ligand and the association of tert-butyl groups with chicken feet.
10. We have also succeeded in synthesizing 1-(tert-butylmethylphosphino)-2-(di-tert-butylphosphino)ethane. This ligand produces enantioselectivities similar to those of 2 in the rhodium-catalyzed asymmetric hydrogenation of α-acetamido dehydroamino acids.
11. Despite the stigma associated with chiral preparatory HPLC separations, this type of separation is becoming increasingly important to the pharmaceutical industry. That 4 contains one chiral center makes it ideal for a chiral separation-based synthesis as well as a strong candidate for production-scale separation via simulated moving bed (SMB) chromatography. See: Welch, W. M.; Ewing, F. E.; Huang, J.; Menniti, F. S.; Pagnozzi, M. J.; Kelly, K.; Seymour, P. A.; Guanowsky, V.; Guhan, S.; Guinn, M. R.; Critchett, D.; Lazzaro, J.; Ganong, A. H.; DeVries, K. M.; Staigers, T. L.; Chenard, B. L. Bioorg. Med. Chem. Lett. 2001, 11, 177.
12. Interestingly, Imamoto's methylene-bridged MiniPHOS ligand can only be synthesized in bischelate form. No bischelate complex was observed during the synthesis of 5. See: Yamanoi, Y.; Imamoto, T. J. Org. Chem. 1999, 64, 2988.
13. Burk. M. J.; De Koning, P. D.; Grote, T. M.; Hoekstra, M. S.; Hoge, G.; Jennings, R. A.; Kissel, W. S.; Le, T. V.; Lennon, I. C.; Mulhern, T. A.; Ramsden, J. A.; Wade, R. A. J. Org. Chem. 2003, 68, 5731.
14. (R,R)-Rh-Me-DuPhos=(-)-1,2-bis((2R,5R)-2,5-dimethylphospholano) -benzene(cyclooctadiene)rhodium (I) tetrafluoroborate.
15. Concentration is an important factor in large-scale hydrogenation because it determines the amount of product that can be produced in a finite reactor volume.
16. No commentary on the mechanism of asymmetric hydrogenation using this catalyst is being presented at this time; however, we feel that it is prudent to associate the ligand and its design, the three hindered quadrant motif, with high enantioselectivity for the demonstrated substrate classes.