An economical, simple, and efficient direct aldol reaction via the double activation of both aldehydes and ketones by ammonia has been developed. An unprecedented tandem Mannich reaction was observed when hydroxybenzaldehydes, pyrrole-2-carboxyaldehyde, and indole-3-carboxyaldehyde were employed to afford 2,2-dimethyl-6-aryl-4-pyrilidinones in moderate to good yields.
An Environment-Friendly and Efficient Method for Aldol Condensation Catalyzed by L-Lysine in Pure Water
作者:Yan Zhang、Man Wang、Jun Liang、Zhi Shang
DOI:10.2174/157017810790533995
日期:2010.1.1
This is a new example of a nonmetallic small-molecule catalyst for direct intermolecular aldol reactions. We found L-lysine is an effective catalyst for this condensation between unmodified acetone and a variety of aldehydes in the presence of pure water. This green catalyst system could be reused.
L-Proline supported on nano gold surface in PEG-400 catalyst system has been developed for use in the direct aldol condensation of acetone with aldehydes. Successful immobilization on surface of gold nanoparticles was confirmed using multiple analytical techniques. The supported catalyst could be separated from the reaction mixture by filtration, and could be reused five times with negligible loss in activity.
A novel DNA-catalyzed aldol reaction in water has been developed. This approach will be helpful in learning the role of DNA as a catalyst in the early stage during the development of life on earth.
Asymmetric organocatalysis with glycosyl-β-amino acids: direct asymmetric aldol reaction of acetone with aldehydes
作者:Namrata Dwivedi、Surendra S. Bisht、Rama P. Tripathi
DOI:10.1016/j.carres.2006.08.007
日期:2006.11
Directasymmetricaldolreaction of acetone with aromatic aldehydes was achieved in good yields and high enantioselectivity using 5-amino-5-deoxy-beta-L-ido-(alpha-D-gluco)-heptofuranuronic acids as a new class of organocatalysts.