- Turkish Journal of Chemistry
- Vol: 44 Issue: 5
- L-proline/cholesterol and diosgenin based thiourea cooperative system for the direct asymmetric aldo...
L-proline/cholesterol and diosgenin based thiourea cooperative system for the direct asymmetric aldol reaction in the presence of water
Authors : Serkan Eymur, Enis Tasci, Arzu Uyanik, Mustafa Yilmaz
Pages : 1278-1284
View : 6 | Download : 3
Publication Date : 9999-12-31
Article Type : Makaleler
Abstract :A series of cholesterol and based hydrophobic urea and thiourea compounds were synthesized and successfully used as a cocatalyst for L-proline catalyzed aldol reactions in the presence of water. The anticonfigured products were obtained with good yields (up to 94%), high diastereoselectivities (up to 95:5), and high enantiomeric excesses (up to 93% ee). The successful results for catalytic efficiency of L-proline in the presence of water reveal the importance of the hydrophobic nature of cholesterol and diosgenin parts of thiourea on the reactivity and selectivity in the presence of water.Keywords : Aldol, organocatalyst, proline, asymmetric synthesis