We have developed a polymer-supported version of Mac-Millan's catalyst by anchoring a tyro sine-derived imidazolidin-4-one by means of a spacer to the monomethyl ether of poly(ethylene glycol) (M-w = 5000 Da). The supported organic catalyst was employed in some 1,3-dipolar cycloadditions involving alpha,beta-unsaturated aldehydes and nitrones. The products were obtained in enantiomeric excesses very similar to those observed with the non-supported catalyst, but the chemical yields were somewhat lower. Exploiting the solubility profile of the polymeric support, the catalyst was readily separated from the reaction products, recovered, and recycled. Catalyst recycling was accompanied by a very marginal erosion (if any) of the enantioselectivity and a more-substantial decrease in chemical efficiency. We ascribe the latter phenomenon mainly to the intrinsic instability of the catalyst under the reaction conditions, which is, however, a common feature of both the non-supported and supported catalysts.

Enantioselective 1,3-dipolar cycloadditions of unsaturated aldehydes promoted by a poly(ethylene glycol)-supported organic catalyst / A. Puglisi, M. Benaglia, M. Cinquini, F. Cozzi, G. Celentano. - In: EUROPEAN JOURNAL OF ORGANIC CHEMISTRY. - ISSN 1434-193X. - :3(2004), pp. 567-573. [10.1002/ejoc.200300571]

Enantioselective 1,3-dipolar cycloadditions of unsaturated aldehydes promoted by a poly(ethylene glycol)-supported organic catalyst

A. Puglisi
Primo
;
M. Benaglia
Secondo
;
M. Cinquini;F. Cozzi
Penultimo
;
G. Celentano
Ultimo
2004

Abstract

We have developed a polymer-supported version of Mac-Millan's catalyst by anchoring a tyro sine-derived imidazolidin-4-one by means of a spacer to the monomethyl ether of poly(ethylene glycol) (M-w = 5000 Da). The supported organic catalyst was employed in some 1,3-dipolar cycloadditions involving alpha,beta-unsaturated aldehydes and nitrones. The products were obtained in enantiomeric excesses very similar to those observed with the non-supported catalyst, but the chemical yields were somewhat lower. Exploiting the solubility profile of the polymeric support, the catalyst was readily separated from the reaction products, recovered, and recycled. Catalyst recycling was accompanied by a very marginal erosion (if any) of the enantioselectivity and a more-substantial decrease in chemical efficiency. We ascribe the latter phenomenon mainly to the intrinsic instability of the catalyst under the reaction conditions, which is, however, a common feature of both the non-supported and supported catalysts.
Catalyst immobilization; Chiral organic catalysts; Cycloadditions; Polymers
Settore CHIM/06 - Chimica Organica
Article (author)
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/143670
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 87
  • ???jsp.display-item.citation.isi??? 87
social impact