L-proline/cholesterol and diosgenin based thiourea cooperative system for the direct asymmetric aldol reaction in the presence of water

Authors : Serkan EYMUR, Enis TASCİ, Arzu UYANİK, Mustafa YİLMAZ

Pages : 1278-1284

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Publication Date : 0000-00-00

Article Type : Research Paper

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 insert ignore into journalissuearticles values(up to 94%);, high diastereoselectivities insert ignore into journalissuearticles values(up to 95:5);, and high enantiomeric excesses insert ignore into journalissuearticles values(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