Synlett 2007(1): 0131-0135  
DOI: 10.1055/s-2006-958428
LETTER
© Georg Thieme Verlag Stuttgart · New York

Simple and Efficient Microwave-Assisted Hydrogenation Reactions at ­Moderate Temperature and Pressure

Grace S. Vanier*
Life Science Division, CEM Corporation, P.O. Box 200, Matthews, NC 28106-0200, USA
Fax: +1(704)8217894; e-Mail: grace.vanier@cem.com;
Further Information

Publication History

Received 15 August 2006
Publication Date:
20 December 2006 (online)

Abstract

A generally applicable method for the introduction of gaseous hydrogen into a sealed reaction system to perform hydrogenation reactions under microwave irradiation has been developed. Several different types of substrates are easily reduced in short reaction times with moderate temperatures between 80 °C and 100 °C with 50 psi of hydrogen. The use of simultaneous cooling is also applied to the hydrogenation of more difficult substrates.

    References and Notes

  • For reviews on microwave chemistry, see:
  • 1a Hayes BL. Microwave Synthesis: Chemistry at the Speed of Light   CEM Publishing; Matthews, NC: 2002. 
  • 1b Loupy A. Microwaves in Organic Synthesis   Wiley-VCH; Weinheim, Germany: 2002. 
  • 1c Microwave Assisted Organic Synthesis   Tierney JP. Lidström P. Blackwell Publishing; Oxford, UK: 2005. 
  • 1d Kappe CO. Stadler A. Microwaves in Organic and Medicinal Chemistry   Wiley-VCH; Weinheim, Germany: 2005. 
  • 2a Dayal B. Ertel NH. Rapole KR. Asgaonkar A. Salen G. Steroids  1997,  62:  451 
  • 2b Banik BK. Barakat KJ. Wagle DR. Manhas MS. Bose AK. J. Org. Chem.  1999,  64:  5746 
  • 2c Daga MC. Taddei M. Varchi G. Tetrahedron Lett.  2001,  42:  5191 
  • 2d Berthold H. Schotten T. Hönig H. Synthesis  2002,  1607 
  • 2e Stiasni N. Kappe CO. ARKIVOC  2002,  (viii):  71 
  • 3a Desai B. Danks TN. Tetrahedron Lett.  2001,  42:  5963 
  • 3b Danks TN. Desai B. Green Chem.  2002,  4:  179 
  • 4 Arcadi A. Cerichelli G. Chiarini M. Vico R. Zorzan D. Eur. J. Org. Chem.  2004,  3404 
  • 5a Lutsenko S. Moberg C. Tetrahedron: Asymmetry  2001,  12:  2529 
  • 5b Reetz MT. Li X. J. Am. Chem. Soc.  2006,  128:  1044 
  • 6 Akisanya J. Danks TN. Garman RN. J. Organomet. Chem.  2000,  603:  240 
  • 7a Wada Y. Yin H. Kitamura T. Yanagida S. Chem. Lett.  2000,  632 
  • 7b Pillai UR. Sahle-Demessie E. Varma RS. Green Chem.  2004,  6:  295 
  • 8a Heller E. Lautenschläger W. Holzgrabe U. Tetrahedron Lett.  2005,  46:  1247 
  • 8b Gustafssön T. Hedenstrom M. Kihlberg J. J. Org. Chem.  2006,  71:  1911 
  • 10 Whittaker AG. Mingos DMP. J. Chem. Soc., Dalton Trans.  2000,  1521 
  • 12a Katritzky AR. Zhang Y. Singh SK. Steel PJ. ARKIVOC  2003,  (xv):  47 
  • 12b Chen JJ. Deshpande SV. Tetrahedron Lett.  2003,  44:  8873 
  • 12c Arvela RK. Leadbeater NE. Org. Lett.  2005,  7:  2101 
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Experimental Set-up.
All reactions were performed with a CEM Discover single mode microwave reactor equipped with a 300 W power source. A 10 mL fiber optic accessory was equipped with a gas inlet to allow introduction of hydrogen gas to the reaction vessel, and each of the reactions was performed in a CEM 10 mL microwave reaction vial. All temperature measurements were performed with a fiber optic probe, and 2 mL of solvent was used for each reaction to ensure ample submersion of the fiber optic probe.
General Procedure.
To a solution of trans,trans-1,4-diphenyl-1,3-butadiene (1, 103 mg, 0.500 mmol) in 2.0 mL of EtOAc was added Pd/C (10 wt%, 5 mg, 0.005 mmol). The reaction vessel was purged three times with hydrogen, charged to 50 psi, and then closed off to the source of hydrogen. The reaction was heated under microwave irradiation to 80 °C with 100 W of power and held for 5 min. Upon cooling to ambient temperature, the reaction mixture was filtered through Celite® and condensed to give 105 mg (>99%) of 1,4-diphenylbutane. 1H NMR (400 MHz, CDCl3): δ = 7.23-7.27 (m, 4 H), 7.14-7.17 (m, 6 H), 2.62 (t, J = 6.6 Hz, 4 H), 1.65 (dt, J = 7.2, 3.8 Hz, 4 H). 13C NMR (100 MHz, CDCl3): δ = 142.66, 128.53, 128.38, 125.77, 35.93, 31.20. Characterization data is consistent with that of commercially available material.

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Isolated yields were difficult due to the low volatility of the products.