Unconventional Bifunctional Lewis-Brønsted Acid Activation Mode in Bicyclic Guanidine-Catalyzed Conjugate Addition ReactionsReportar como inadecuado




Unconventional Bifunctional Lewis-Brønsted Acid Activation Mode in Bicyclic Guanidine-Catalyzed Conjugate Addition Reactions - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore



Present address: Energetic Research Institute, Nanyang Technological University, 50 Nanyang Ave, Singapore 639798, Singapore.





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Author to whom correspondence should be addressed.



Academic Editor: Choon-Hong Tan

Abstract 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 pKa, while the best electrophiles are flexible 1,4-diamide and 1,4-diester conjugated systems. View Full-Text

Keywords: organocatalysis; activation mode; guanidine; bifunctional activation; mechanism; DFT calculations organocatalysis; activation mode; guanidine; bifunctional activation; mechanism; DFT calculations





Autor: Bokun Cho † and Ming Wah Wong *

Fuente: http://mdpi.com/



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