Unconventional Bifunctional Lewis-Brønsted Acid Activation Mode in Bicyclic Guanidine-Catalyzed Conjugate Addition Reactions

Molecules

Bokun Cho¹  Ming Wah Wong¹ 

关键词: organocatalysis;    activation mode;    guanidine;    bifunctional activation;    mechanism;    DFT calculations;   

DOI  :  10.3390/molecules200815108

来源: mdpi

【 摘 要 】

DFT calculations have demonstrated that the unconventional bifunctional Brønsted-Lewis acid activation mode is generally applicable to a range of nucleophilic conjugate additions catalyzed by bicyclic guanidine catalysts. It competes readily with the conventional bifunctional Brønsted acid mode of activation. The optimal pro-nucleophiles for this unconventional bifunctional activation are acidic substrates with low pK_a, while the best electrophiles are flexible 1,4-diamide and 1,4-diester conjugated systems.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.