Binap-silver salts as chiral catalysts for the enantioselective 1,3-dipolar cycloaddition of azomethine ylides and alkenes
作者:Juan Mancebo-Aracil、María Martín-Rodríguez、Carmen Nájera、José M. Sansano、Paulo R.R. Costa、Evanoel Crizanto de Lima、Ayres G. Dias
DOI:10.1016/j.tetasy.2012.10.015
日期:2012.12
Binap-AgSbF6 catalyzed 1,3-dipolarcycloadditions between azomethineylides and electrophilicalkenes are described and compared with analogous transformations mediated by other Binap-silver(I) salt complexes. Maleimides and 1,2-bis(phenylsulfonyl)ethylene are suitable dipolarophiles for obtaining very good enantioselectivities, even better values are generated by a multicomponent version. There are
Synthesis of Prolines by Enantioselective 1,3-Dipolar Cycloaddition of Azomethine Ylides and Alkenes Catalyzed by Chiral Phosphoramidite-Silver(I) Complexes
作者:Carmen Nájera、María de Gracia Retamosa、María Martín-Rodríguez、José M. Sansano、Abel de Cózar、Fernando P. Cossío
DOI:10.1002/ejoc.200900774
日期:2009.11
This work was supported by the DGES of the Spanish Ministerio de Educacion y Ciencia (MEC) (Consolider INGENIO 2010 CSD2007-00006, CTQ2007-62771/BQU and CTQ2004-00808/BQU) and by the University of Alicante.
Recoverable (<i>R</i>)- and (<i>S</i>)-Binap−Ag(I) Complexes for the Enantioselective 1,3-Dipolar Cycloaddition Reaction of Azomethine Ylides
作者:Carmen Nájera、M. de Gracia Retamosa、José M. Sansano
DOI:10.1021/ol701577k
日期:2007.9.1
The first enantioselective 1,3-dipolar cycloaddition reaction of amino acid derived azomethine ylides and maleimides catalyzed by very stable and recyclable chiral (R)- or (S)-binap-AgClO(4) complexes is described. The reactions are performed at room temperature, in good yields, with high endo diastereoselectivity and enantioselectivity, the complex being recovered by simple filtration.
Enantioselective synthesis of polysubstituted prolines by Binap-silver-catalyzed 1,3-dipolar cycloadditions
作者:Carmen Nájera、M. de Gracia Retamosa、José M. Sansano、Abel de Cózar、Fernando P. Cossío
DOI:10.1016/j.tetasy.2008.12.021
日期:2008.12
The enantioselective 1,3-dipolar cycloaddition reaction of stabilized azomethine ylides, generated from iminoesters, with maleimides was efficiently achieved by intermediacy of an equimolar mixture of chiral (R)- or (S)-Binap and AgClO4. The high stability of the titled catalytic metal-complex to light exposure and its insolubility in toluene made possible its recovery and reutilization in other new process. In order to get a better understanding of the behavior of these chiral catalysts, we have carried out DFT1 calculations demonstrating the experimentally observed high enantio- and endo-selectivity through a very asynchronous transition state. (C) 2009 Elsevier Ltd. All rights reserved.