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Nouvelle réaction domino-multicomposés pour la synthèse totalement régiosélective de pyridines hautement fonctionnalisées

Christophe Allais

出版	2010
URL	http://books.google.com.hk/books?id=zj6vngEACAAJ&hl=&source=gbs_api

註釋

This work focused on the elaboration of a new Michael addition-initiated multicomponent reaction promoted by molecular sieves for the synthesis of highly substituted pyridines. Thus, mixing a 2- unsubstituted 1,3-dicarbonyl derivative, a Michael acceptor and ammonium acetate led to a wide range of polysubstituted mono- and polycyclic pyridines. This multicomponent sequence is in accordance with sustainable chemistry which is currently a major concern for organic chemists. After optimization, the general applicability of the method allowed the access to potent pharmaceutical cores such as nicotinamide and 4-azafluorenone derivatives. A limitation of the strategy consisted in the impossibility to functionalize the 4-position. To overcome this drawback, a-ketocarbonyls as activated Michael acceptors have been used for the first time as versatile partners in a three-component sequence and allowed selective and simultaneous incorporation of a substituent at the 4-position and a synthetically useful functionality at the strategic 2-position. Finally, an application of this approach was devoted to the elaboration of pyridine atropisomers. This study opened attractive prospect in view of emergence of promising ligands.