Prolinamides of Aminouracils, Organocatalyst Modifiable by Complementary Modules

• Published in: European journal of organic chemistry Vol. 2018; no. 41; pp. 5763 - 5772
• Main Authors: Ruíz‐Pérez, Karen M., Quiroz‐García, Beatriz, Hernández‐Rodríguez, Marcos
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 08.11.2018; Wiley Subscription Services, Inc
• Subjects: Adducts; Aldol reactions; Catalysis; Catalysts; Chemical synthesis; Chemistry; Chemistry, Organic; Enantiomers; Functional groups; Modules; Nitrogen heterocycles; Organocatalysis; Physical Sciences; Science & Technology; Selectivity; Self‐assembly; Supramolecular chemistry; Self-assembly; Nitrogen heterocycles; Aldol reactions; MECHANISMS; Organocatalysis; 5-AMINOPYRIMIDINES; Supramolecular chemistry
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.201800886

We report the synthesis and evaluation of prolinamide organocatalysts that incorporate aminouracils. The features of these catalysts are enhanced NH acidity of the amide because of the electron‐withdrawing nature of the heterocycle, an additional hydrogen‐bond donor at the α or β positions of this functional group (using 6‐aminouracil or 5,6‐diaminouracil respectively), and it can be recovered due to its low solubility and used again without decreasing the enantioselectivity. A unique feature of these systems is the self‐assembly capability with complementary modules by Watson–Crick interactions. These supramolecular adducts behave differently from the catalyst alone, some of them have lower performance but others improve the selectivity of the product. Therefore, this approach avoids the synthesis of many catalysts. Prolinamide organocatalysts with aminouracils have the features of enhanced NH acidity, an additional hydrogen‐bond donor and the self‐assembly with complementary modules by Watson–Crick pairing. Each module affects the selectivity of the reaction and particularly 2,6‐diaminopyridine is beneficial to the selectivity in the reaction.