Markedly chemoselective hydrogenation with retention of benzyl ester and N-Cbz functions using a heterogeneous Pd-fibroin catalyst

Tetrahedron Letters

Volumn 44, Issue 46, 2003, Pages 8437-8439

  Sajiki, Hironao ^a   Ikawa, Takashi ^a   Hirota, Kosaku ^a  

^a GIFU PHARMACEUTICAL UNIVERSITY   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

ACETYLENE; ALKENE; AZIDE; BENZYL DERIVATIVE; ESTER DERIVATIVE; ETHYLENEDIAMINE; FIBROIN; PALLADIUM;

ARTICLE; CATALYSIS; CATALYST; CHEMICAL REACTION; HYDROGENATION;

EID: 0141922092     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2003.09.137     Document Type: Article

References (20)

1. For selected reviews on reductions, see: (a) Larock, R. C. Comprehensive Organic Transformations; 2nd ed.; Wiley-VCH: New York, 1999; (b) Nishimura, S. Handbook of Heterogeneous Catalytic Hydrogenation for Organic Synthesis; Wiley-Interscience: New York, 2001; (c) Hudlicky, M. Reductions in Organic Chemistry; 2nd ed.; ACS: Washington, DC, 1996; (d) Rylander, P. N. Hydrogenation Methods; Academic Press: New York, 1985.
2. For selected reviews on reductions, see: (a) Larock, R. C. Comprehensive Organic Transformations; 2nd ed.; Wiley-VCH: New York, 1999; (b) Nishimura, S. Handbook of Heterogeneous Catalytic Hydrogenation for Organic Synthesis; Wiley-Interscience: New York, 2001; (c) Hudlicky, M. Reductions in Organic Chemistry; 2nd ed.; ACS: Washington, DC, 1996; (d) Rylander, P. N. Hydrogenation Methods; Academic Press: New York, 1985.
3. For selected reviews on reductions, see: (a) Larock, R. C. Comprehensive Organic Transformations; 2nd ed.; Wiley-VCH: New York, 1999; (b) Nishimura, S. Handbook of Heterogeneous Catalytic Hydrogenation for Organic Synthesis; Wiley-Interscience: New York, 2001; (c) Hudlicky, M. Reductions in Organic Chemistry; 2nd ed.; ACS: Washington, DC, 1996; (d) Rylander, P. N. Hydrogenation Methods; Academic Press: New York, 1985.
4. For selected reviews on reductions, see: (a) Larock, R. C. Comprehensive Organic Transformations; 2nd ed.; Wiley-VCH: New York, 1999; (b) Nishimura, S. Handbook of Heterogeneous Catalytic Hydrogenation for Organic Synthesis; Wiley-Interscience: New York, 2001; (c) Hudlicky, M. Reductions in Organic Chemistry; 2nd ed.; ACS: Washington, DC, 1996; (d) Rylander, P. N. Hydrogenation Methods; Academic Press: New York, 1985.
5. Green T.W., Wuts P.G.M. Protective Groups in Organic Synthesis. 3rd ed :1999;John Wiley & Sons, New York.
6. Misiti D., Zappia G., Monach G. D. Synthesis. 1999;873-877.
7. Kuzuhara et al. have reported the chemoselective hydrogenation of an azido group in the presence of an aliphatic N-Cbz protective group using Raney Ni, which must be added into the reaction mixture in small portions with careful monitoring to avoid cleavage of the N-Cbz group: Kuzuhara H., Mori O., Emoto S. Tetrahedron Lett. 1976;379-382.
8. Sajiki H., Hattori K., Hirota K. J. Org. Chem. 63:1998;7990-7992.
9. Hattori K., Sajiki H., Hirota K. Tetrahedron. 56:2000;8433-8441.
10. Quit a few methods to maintain the benzyl ester intact during a synthetic process involving conjugate reduction (non-hydrogenation) steps have been reported. (a) Mathoney, W. S.; Brestensky, D. M.; Stryker, J. M. J. Am. Chem. Soc. 1988, 110, 291-293; (b) Evans, D. A.; Fu, G. C. J. Org. Chem. 1990, 55, 5678-5680; (c) Kelly, T. R.; Xu, W.; Ma, Z.; Li, Q.; Bhushan, V. J. Am. Chem. Soc. 1993, 115, 5843-5844.
11. Quit a few methods to maintain the benzyl ester intact during a synthetic process involving conjugate reduction (non-hydrogenation) steps have been reported. (a) Mathoney, W. S.; Brestensky, D. M.; Stryker, J. M. J. Am. Chem. Soc. 1988, 110, 291-293; (b) Evans, D. A.; Fu, G. C. J. Org. Chem. 1990, 55, 5678-5680; (c) Kelly, T. R.; Xu, W.; Ma, Z.; Li, Q.; Bhushan, V. J. Am. Chem. Soc. 1993, 115, 5843-5844.
12. Quit a few methods to maintain the benzyl ester intact during a synthetic process involving conjugate reduction (non-hydrogenation) steps have been reported. (a) Mathoney, W. S.; Brestensky, D. M.; Stryker, J. M. J. Am. Chem. Soc. 1988, 110, 291-293; (b) Evans, D. A.; Fu, G. C. J. Org. Chem. 1990, 55, 5678-5680; (c) Kelly, T. R.; Xu, W.; Ma, Z.; Li, Q.; Bhushan, V. J. Am. Chem. Soc. 1993, 115, 5843-5844.
13. Sajiki H., Ikawa T., Yamada H., Tsubouchi K., Hirota K. Tetrahedron Lett. 44:2003;171-174.
14. Akabori and Izumi et al. reported the pioneering preparation of the silk-supported palladium catalyst in a fundamentally different way although their catalyst indicates totally different catalyst activity from our Pd/Fib catalyst. (a) Akabori, S.; Sakurai, S.; Izumi, Y.; Fujii, Y. Nature 1956, 178, 323-324; (b) Izumi, Y. Bull. Chem. Soc. Jpn. 1959, 32, 932-936, 936-942 and 942-945; (c) Akamatsu, A.; Izumi, Y.; Akabori, S. Bull. Chem. Soc. Jpn. 1961, 34, 1067-1072; (d) Akamatsu, A.; Izumi Y.; Akabori, S. Bull. Chem. Soc. Jpn. 1961, 35, 1706-1711.
15. Akabori and Izumi et al. reported the pioneering preparation of the silk-supported palladium catalyst in a fundamentally different way although their catalyst indicates totally different catalyst activity from our Pd/Fib catalyst. (a) Akabori, S.; Sakurai, S.; Izumi, Y.; Fujii, Y. Nature 1956, 178, 323-324; (b) Izumi, Y. Bull. Chem. Soc. Jpn. 1959, 32, 932-936, 936-942 and 942-945; (c) Akamatsu, A.; Izumi, Y.; Akabori, S. Bull. Chem. Soc. Jpn. 1961, 34, 1067-1072; (d) Akamatsu, A.; Izumi Y.; Akabori, S. Bull. Chem. Soc. Jpn. 1961, 35, 1706-1711.
16. Akabori and Izumi et al. reported the pioneering preparation of the silk-supported palladium catalyst in a fundamentally different way although their catalyst indicates totally different catalyst activity from our Pd/Fib catalyst. (a) Akabori, S.; Sakurai, S.; Izumi, Y.; Fujii, Y. Nature 1956, 178, 323-324; (b) Izumi, Y. Bull. Chem. Soc. Jpn. 1959, 32, 932-936, 936-942 and 942-945; (c) Akamatsu, A.; Izumi, Y.; Akabori, S. Bull. Chem. Soc. Jpn. 1961, 34, 1067-1072; (d) Akamatsu, A.; Izumi Y.; Akabori, S. Bull. Chem. Soc. Jpn. 1961, 35, 1706-1711.
17. Akabori and Izumi et al. reported the pioneering preparation of the silk-supported palladium catalyst in a fundamentally different way although their catalyst indicates totally different catalyst activity from our Pd/Fib catalyst. (a) Akabori, S.; Sakurai, S.; Izumi, Y.; Fujii, Y. Nature 1956, 178, 323-324; (b) Izumi, Y. Bull. Chem. Soc. Jpn. 1959, 32, 932-936, 936-942 and 942-945; (c) Akamatsu, A.; Izumi, Y.; Akabori, S. Bull. Chem. Soc. Jpn. 1961, 34, 1067-1072; (d) Akamatsu, A.; Izumi Y.; Akabori, S. Bull. Chem. Soc. Jpn. 1961, 35, 1706-1711.
18. Sajiki H., Hattori K., Hirota K. Chem. Eur. J. 6:2000;2200-2204.
19. We have quite recently reported the frequent and unexpected cleavage of tert-butyldimethylsilyl (TBDMS) ethers to form the parent alcohols under mild hydrogenation conditions using 10% Pd/C in MeOH although TBDMS ethers have been believed to be stable under hydrogenation conditions. Furthermore, we have reported a remarkable solvent effect toward the Pd/C-catalyzed cleavage of TBDMS and triethylsilyl (TES) ethers and it was applied to the development of a chemoselective hydrogenation method for olefin, benzyl ether and acetylene functionalities distinguishing from the TBDMS and TES protective groups of a hydroxy group by the employment of EtOAc or MeCN as a solvent. See: Sajiki H., Ikawa T., Hattori K., Hirota K. Chem. Commun. 2003;654-655. and references cited therein.
20. The catalyst activity of commercial 5% Pd/C (Aldrich) toward reducible functionalities is much higher than the catalyst activity of 2.5% Pd/Fib. The olefins of 4 and 7 were completely hydrogenated within 1 h (Scheme 2) while the complete hydrogenation of the olefins required much longer time (24 h and 5 h, respectively; Table 1, entries 5 and 9).