Synfacts 2006(3): 0274-0274  
DOI: 10.1055/s-2006-931987
Bioorganic Chemistry and Organocatalysis
© Georg Thieme Verlag Stuttgart · New York

Highly Diastereo- and Enantioselective Direct Aldol Reactions in Water

Contributor(s): Benjamin List, Subhas Chandra Pan
Y. Hayashi*, T. Sumiya, J. Takahashi, H. Gotoh, T. Urushima, M. Shoji
Tokyo University of Science, Japan
Further Information

Publication History

Publication Date:
21 February 2006 (online)

Significance

Siloxyproline catalysts have been identified as effective catalysts for the enantioselective direct aldol reaction in water without using an organic solvent. With 10 mol% of catalyst 1, excellent enantioselectivities (over 95%) and anti selectivities (dr = 4.7:1-25:1) are obtained with different aromatic and aliphatic aldehydes. These selectivities are higher than for the reaction performed in organic solvents. Catalyst loadings can be reduced to 1 mol% and the use of acyclic ketones instead of cyclohexanone is also reported.