One-step, efficient synthesis of combined threonine-surfactant organocatalysts for the highly enantioselective direct aldol reactions of cyclic ketones with aromatic aldehydes in the presence of water

In this work a new class of organocatalysts have been designed and synthesized in one step by a rational combination of threonine with acyl chlorides at room temperature in trifluoroacetic acid to make a series of novel combined threonine-surfactant organocatalysts readily available on a large-scale No protecting groups or chromatographic techniques are Involved in the procedures while certain combined threonine-surfactant organocatalysts mediate the direct aldol reactions of cyclic ketones with aromatic aldehydes to provide the aldol products in good yields with enantioselectivities of up to 99% (C) 2010 Elsevier Ltd All rights reserved