Reliable and Safe, Gram-Scale Hydrogenation and Hydrogenolysis of O-Benzyl Ether Groups with In Situ Pd⁰/C Catalyst

Abstract

Hydrogenation of alkenes, alkynes, and hydrogenolysis of O-benzyl ethers with Pd⁰/C catalyst generated in situ can be readily scaled up under safer conditions than with traditional procedures. The precise control of the palladium loading and the mild conditions developed allow the formation of a very active and reliable Pd⁰/C catalyst, leading to highly reproducible results.

hydrogenation - hydrogenolysis - palladium - charcoal - gram-scale synthesis

References

1

Present address: Université de Nantes.

2a Nishimura S. Handbook of Heterogeneous Catalytic Hydrogenation for Organic Synthesis   Wiley; New York: 2001. 

2b Hudlick M. Reductions in Organic Chemistry   2nd ed.:  American Chemical Society; Washington DC: 1996. 

2c Rylander PN. Hydrogenation Methods   Academic Press; New York: 1985. 

3 Rylander PN. Hydrogenation and Dehydrogenation, In Ullmann’s Encyclopedia of Industrial Chemistry   Wiley-VCH; Weinheim: 2005. 

4 Chaston JC. Sercombe EJ. Plat. Met. Rev.  1961,  5:  122 

5 Felpin F.-X. Fouquet E. Chem. Eur. J.  2010,  16:  12440 

6

Activated Carbon, Darco® G-60, 100 mesh, was used in this study. However, we did not observe dramatic differences with other types of charcoal.

7a Dayal B. Ertel NH. Rapole KR. Asgaonkar A. Salen G. Steroids  1997,  62:  451 

7b Akiyama R. Kobayashi S. J. Am. Chem. Soc.  2003,  125:  3412 

7c Okamoto K. Akiyama R. Kobayashi S. J. Org. Chem.  2004,  69:  2871 

7d Kwon MS. Kim N. Park CM. Lee JS. Kang KY. Park J. Org. Lett.  2005,  7:  1077 

7e Park CM. Kwon MS. Park J. Synthesis  2006,  3790 

8 Serijan KT. Wise PH. J. Am. Chem. Soc.  1951,  73:  4766 

9 Richer J.-C. Eliel E. J. Org. Chem.  1961,  26:  972 

10 Stein KA. Toogood PL. J. Org. Chem.  1995,  60:  8110 

11 Kaeding WW. J. Org. Chem.  1964,  29:  2556 

12 Thimann KV. Biochem. J.  1930,  24:  368 

13 Maryott AA. Hobbs ME. Gross PM. J. Am. Chem. Soc.  1949,  71:  1671