New Strategies for N-Heterocyclic Carbenes Catalyzed Annulations

• Κύριος συγγραφέας: Chen, Xiangyu (Συγγραφέας)
• Συγγραφή απο Οργανισμό/Αρχή: SpringerLink (Online service)
• Μορφή: Ηλεκτρονική πηγή Ηλ. βιβλίο
• Γλώσσα: English
• Έκδοση: Singapore : Springer Singapore : Imprint: Springer, 2017.
• Σειρά: Springer Theses, Recognizing Outstanding Ph.D. Research,
• Θέματα: Chemistry.; Organic chemistry.; Medicinal chemistry.; Catalysis.; Organic Chemistry.; Medicinal Chemistry.

 This thesis focuses on NHC-catalyzed annulation of nitroalkenes, enals and α,β-unsaturated carboxylic acids. (1) NHCs were found to be efficient catalysts for the [4+2] annulation of β-substituted nitroalkenes. The scope of Rauhut–Currier reaction was successfully extended to the most challenging β-substituted alkenes by this method; (2) Enals were successfully used for [4+2] annulations with azodicarboxylates catalyzed by NHC via γ-addition. Highly enantiopure tetrahydropyridazinones and γ-amino acid derivatives could be easily prepared by subsequent transformations of the resulting dihydropyridazinones. (4) The readily available α,β-unsaturated carboxylic acids were first successfully employed to generate the α,β-unsaturated acyl azolium intermediates by using NHC for the enantioselective [3+2] and [3+3] annulations. 

 Introduction -- NHC-catalyzed Annulations of Nitroalkenes -- NHC-catalyzed Enantioselective Annulations of Enals -- NHC-catalyzed Enantioselective Annulations of α,β-unsaturated Carboxylic Acids -- Experimental Part -- Research Summary.