Regioselective Hydrogenation of α,β-Unsaturated Ketones over Wilkinson’s Catalyst

Abstract

The reactivity of a variety of α,β-unsaturated acyclic and cyclic ketones towards regioselective hydrogenation in the presence of Wilkinson’s catalyst was determined. Hydrogenation of sterically hindered α,β-unsaturated ketones proceeded at inefficient rates, if at all.

Key words

enones - regioselectivity - hydrogenation - Wilkinson’s catalyst - flavonoids

References

• 1 Shimizu H. Nagasaki I. Saito T. Tetrahedron  2005,  61:  5405 
• 2 Jourdant A. González-Zamora E. Zhu J. J. Org. Chem.  2002,  67:  3163 
• 3 Dahlenberg L. Coord. Chem. Rev.  2005,  249:  2962 
• 5 Mahittikul A. Prasassarakich P. Rempel GL. J. Mol. Catal. A: Chem.  2009,  297:  135 
• 6 Yi CS. Lee DW. Organometallics  1999,  18:  5152 
• 7a Van Laren MW. Duin MA. Klerk C. Naglia M. Rogolino D. Pelagatti P. Bacchi A. Pelizzi C. Elsevier CJ. Organometallics  2002,  21:  1546 
• 7b Nelson DJ. Li R. Brammer C. J. Org. Chem.  2005,  70:  761 
• 8 Kokkinos NC. Lazaridou A. Nikolaou N. Papadogianakis G. Psaroudakis N. Chatzigakis AK. Papadopoulos CE. Appl. Catal., A  2009,  363 (1-2):  129 
• 9 He J. Zheng J. Lui J. She X. Pan X. Org. Lett.  2006,  8:  4637 
• 10 Hashimoto N. Aoyama T. Shioiri T. Chem. Pharm. Bull.  1982,  30:  119 

4

As the nonvolatile substrates were solids, they had to be dissolved in solvent, which necessitated the use of the larger reactor for better mass transfer.