CuCl2-catalyzed heterocyclodehydration of readily available 3-yne-1,2-diols and 1-amino-3-yn-2-ol derivatives afforded substituted furans and pyrroles, respectively, in good to high yields (53-99%) under mild conditions (MeOH as the solvent, 80-100 degrees C, 1-24 h). In the case of 2,2-dialkynyl-1,2-diols, bearing an additional alkynyl substituent at C-2, a cascade process, corresponding to copper-catalyzed heterocyclodehydration followed by acid-catalyzed hydration of the triple bond, was realized when the reaction was carried out in the presence of both CuCl2 and TsOH, leading to 3-acylfurans in one step and high yields (75-84%). Under the same conditions, N-Boc-2-alkynyl-1-amino-3-yn-2-ols were converted into the corresponding N-unsubstituted 3-acylpyrroles in low to fair yields (19-59%). However, working in the presence of added water and a large excess of CO2 (40 atm), in addition to CuCl2 and TsOH, caused a significant improvement of the yields of 3-acylpyrroles (68-87%), thus making the method of general synthetic applicability

Copper-Catalyzed Synthesis of Substituted Furans and Pyrroles by Heterocyclodehydration and Tandem Heterocyclodehydration-Hydration of 3-Yne-1,2-diols and 1-Amino-3-yn-2-ol Derivatives

Gabriele B.;Veltri L.;Plastina P.;Mancuso R.;
2013-01-01

Abstract

CuCl2-catalyzed heterocyclodehydration of readily available 3-yne-1,2-diols and 1-amino-3-yn-2-ol derivatives afforded substituted furans and pyrroles, respectively, in good to high yields (53-99%) under mild conditions (MeOH as the solvent, 80-100 degrees C, 1-24 h). In the case of 2,2-dialkynyl-1,2-diols, bearing an additional alkynyl substituent at C-2, a cascade process, corresponding to copper-catalyzed heterocyclodehydration followed by acid-catalyzed hydration of the triple bond, was realized when the reaction was carried out in the presence of both CuCl2 and TsOH, leading to 3-acylfurans in one step and high yields (75-84%). Under the same conditions, N-Boc-2-alkynyl-1-amino-3-yn-2-ols were converted into the corresponding N-unsubstituted 3-acylpyrroles in low to fair yields (19-59%). However, working in the presence of added water and a large excess of CO2 (40 atm), in addition to CuCl2 and TsOH, caused a significant improvement of the yields of 3-acylpyrroles (68-87%), thus making the method of general synthetic applicability
2013
cyclodehydration; cyclization
File in questo prodotto:
Non ci sono file associati a questo prodotto.

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/20.500.11770/131653
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? 5
  • Scopus 50
  • ???jsp.display-item.citation.isi??? 49
social impact