Synlett 2006(18): 3013-3016  
DOI: 10.1055/s-2006-951518
LETTER
© Georg Thieme Verlag Stuttgart · New York

RuHCl(CO)(PPh3)3-Catalyzed Reductive Dimerization of α,β-Unsaturated Aldehydes Leading to α-Hydroxymethyl Ketones

Takashi Doi, Takahide Fukuyama, Satoshi Minamino, Ilhyong Ryu*
Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
Fax: +81(72)2549695; e-Mail: ryu@c.s.osakafu-u.ac.jp;
Further Information

Publication History

Received 26 April 2006
Publication Date:
25 October 2006 (online)

Abstract

The reductive dimerization α,β-unsaturated aldehydes to give saturated ketones was achieved using RuHCl(CO)(PPh3)3 as a catalyst in the presence of secondary alcohols as hydrogen source. The reaction is likely to proceed via the hydroruthenation of α,β-unsaturated aldehydes followed by aldol reaction of the resultant ruthenium enolates with α,β-unsaturated aldehydes to give unsaturated α-hydroxymethyl ketones, which undergo transfer hydrogenation to give α-hydroxymethyl ketones.

    References and Notes

  • 1a Transition Metals for Organic Synthesis   Vols. 1 and 2:  Beller M. Bolm C. Wiley-VCH; Weinheim: 1998. 
  • 1b Applied Homogeneous Catalysis with Organometallic Compounds   Vols. 1 and 2:  Cornils B. Herrmann WA. VCH; Weinheim: 1996. 
  • 2 Doi T. Fukuyama T. Minamino S. Husson G. Ryu I. Chem. Commun.  2006,  1875 
  • 3 Doi T. Fukuyama T. Horiguchi J. Okamura T. Ryu I. Synlett  2006,  721 
  • For studies on ruthenium enolate complexes, see:
  • 5a Hartwig JF. Bergman RG. Andersen RA. Organometallics  1991,  10:  3326 
  • 5b Tasley BT. Rapta M. Kulawiec RJ. Organometallics  1996,  15:  2852 
  • For Ru-catalyzed aldol-type reactions, see:
  • 6a Matsuda I. Shibata M. Sato S. J. Organomet. Chem.  1988,  340:  C5 
  • 6b Sato S. Matsuda I. Shibata M. J. Organomet. Chem.  1989,  377:  347 
  • 6c Naota T. Taki T. Mizuno M. Murahashi S.-I. J. Am. Chem. Soc.  1989,  111:  5954 
  • 6d Mizuho Y. Kasuga N. Komiya S. Chem. Lett.  1991,  2127 
  • 6e Murahashi S.-I. Naota T. Taki H. Mizuno M. Takaya H. Komiya S. Mizuho Y. Oyasato N. Hiraoka M. Hirano M. Fukuoka A. J. Am. Chem. Soc.  1995,  117:  12436 
  • 6f Uma R. Davies M. Crévisy C. Grée R. Tetrahedron Lett.  2001,  42:  3069 
  • 6g Wang M. Yang X.-F. Li C.-J. Eur. J. Org. Chem.  2003,  998 
  • 6h Yang X.-F. Wang M. Varma RS. Li C.-J. Org. Lett.  2003,  5:  657 
  • 6i Yang X.-F. Wang M. Varma RS. Li C.-J. J. Mol. Catal. A: Chem.  2004,  214:  147 
  • 6j Martín-Matute B. Bogár K. Edin M. Kaynak FB. Bäckvall J.-E. Chem. Eur. J.  2005,  11:  5832 
  • For reviews on catalytic reductive aldol coupling, see:
  • 7a Motherwell WB. Pure Appl. Chem.  2002,  74:  135 
  • 7b Huddleston RR. Krische MJ. Synlett  2003,  12 
  • 7c Jang H.-Y. Krische MJ. Eur. J. Org. Chem.  2004,  3953 
  • 7d Jang H.-Y. Krische MJ. Acc. Chem. Res.  2004,  37:  653 
  • 7e Chiu P. Synthesis  2004,  2210 
4

After 15 min, 3a contained ca. 17% of double-bond isomers.

8

General Procedure for the RuHCl(CO)(PPh 3 ) 3 -Catalyzed Reductive Dimerization of α,β-Unsaturated Aldehyde. A mixture of 1a (103 mg, 1.03 mmol), 2-PrOH (63 mg, 1.05 mmol), and RuHCl(CO)(PPh3)3 (96.0 mg, 0.1 mmol) in benzene (6 mL) was stirred at reflux for 10 h under an atmosphere of N2. Purification by silica gel column chromatography and preparative HPLC equipped with GCP column gave α-hydroxymethyl ketone 2a (59.0 mg, 59%).