Facile Method for 1,3-Dipolar Cycloaddition Reaction of Azomethine Ylides: Highly Stereoselective Synthesis of Substituted Pyrrolidine Derivatives
作者:Serkan Yavuz、Hamdi Özkan、Gülçin Tok、Ali Dişli
DOI:10.1002/jhet.1540
日期:2013.11
The substituted pyrolidine derivatives with high stereoselectivity were obtained through cycloadditionreaction in the presence of a Lewis acid namely diethylzinc by solvent‐free grinding method.
Binap-Gold(I) versus Binap-Silver Trifluoroacetate Complexes as Catalysts in 1,3-Dipolar Cycloadditions of Azomethine Ylides
作者:María Martín-Rodríguez、Carmen Nájera、José M. Sansano、Abel de Cózar、Fernando P. Cossío
DOI:10.1002/chem.201101606
日期:2011.12.9
The 1,3‐dipolarcycloaddition between azomethine ylides and alkenes is efficiently catalysed by [(Sa)‐Binap‐Au(tfa)}2] (Binap=2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl; tfa=trifluoroacetyl). Maleimides, 1,2‐bis(phenylsulfonyl)ethylene, chalcone and nitrostyrene were suitable dipolarophiles even when using sterically hindered 1,3‐dipole precursors. The results obtained in these transformations improve
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.
Novel complexes of 1,2-P,N-bidentate ferrocenyl ligands with AgOAc or with [RuCl2(PPh3)3] as catalysts have been studied in asymmetric synthesis. The catalytic activity of these systems have been studied in [3+2]-cycloaddition of azomethine ylides with olefins and the asymmetric transferhydrogenation of ketones.
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.