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.
A new chiral phosphine oxide ligand for enantioselective 1,3-dipolar cycloaddition reactions of azomethine ylides
作者:Serap Eröksüz、Özdemir Dogan、Philip P. Garner
DOI:10.1016/j.tetasy.2010.10.002
日期:2010.10
A new set of phosphorus-containing chiral ligands has been synthesized and used with silver(I) for the catalytic asymmetric 1 3-dipolar cycloaddition reaction of azomethine ylides One of these ligands (POFAM6) was found to produce an effective catalyst for the asymmetric 1 3 dipolar cycloaddition reaction of azomethine ylides with electron deficient dipolarophiles to form pyrrolidines in up to 97% yield and 89% (C) 2010 Elsevier Ltd All rights reserved
Switching the Stereoselectivity: (Fullero)Pyrrolidines “a la Carte”
作者:Enrique E. Maroto、Salvatore Filippone、Angel Martín-Domenech、Margarita Suarez、Nazario Martín
DOI:10.1021/ja306105b
日期:2012.8.8
Stereodivergent syntheses of cis/trans pyrrolidino[3,4:1,2]fullerenes and endo/exo pyrrolidines are reported with high enantioselectivity levels. Fullerenes are revealed as a useful benchmark to develop suitable catalysts to control the stereochemical outcome and to shed light on the mechanism involved in the related 1,3-dipolar cycloaddition.