Enantioselective decarboxylative michael and aldol reactions with bifunctional squaramide organocatalysts

Bayer, Ezgi
The decarboxylative Michael and aldol reactions are quite new in the asymmetric studies and are used for forming new C-C bonds by nucleophilic attack. In the first part of this thesis, decarboxylative Michael reaction of isatylidene malononitriles with ethyl benzoyl acetate was accomplished in the presence of chiral 2- aminoDMAP and quinine derived bifunctional acid/base organocatalysts, which are developed in our research group. In this part, 12 derivatives were synthesized with quinine based 1-adamantyl squaramide bifunctional organocatalyst up to 46% ee under the optimized condition with 10 mol% catalysts loading at -20 °C. In the second part, the enantioselective decarboxylative aldol reactions of α- amidohemimalonates with various aldehydes were accomplished in the presence of the organocatalysts developed in our research group. In this part, the best result was achieved with 10 mol% t-butyl squaramide quinine organocatalyst as 63% ee.