The reactivity of 2-(prop-2-ynylthio)-1H-benzo[d]imidazoles and their corresponding hydrobromide salts under PdI2/KI-catalyzed oxidative aminocarbonylation conditions has been studied. It is found that 2-prop-2-ynylsulfanyl-3H-benzimidazolium salts, when allowed to react with amines, carbon monoxide, and oxygen, under the catalytic action of PdI2 (1mol%) in conjunction with KI (1equiv), under suitable conditions (80°C and 20atm of a 4:1 mixture of CO/air, in MeCN, and in the presence of a six-fold excess of amine, for 15h), could be selectively converted into 2-benzo[4,5]imidazo[2,1-b]thiazol-3-yl-N,N-dialkylacetamides in 60-78% yields, through an oxidative aminocarbonylation/heterocyclization process. The structure of a representative product, 2-benzo[4,5]imidazo[2,1-b]thiazol-3-yl-1-pyrrolidin-1-ylethanone, was confirmed by X-ray diffraction analysis.

Palladium-catalyzed carbonylative multicomponent synthesis of functionalized benzimidazothiazoles

VELTRI, Lucia
;
MANCUSO R;GABRIELE, Bartolo
2016

Abstract

The reactivity of 2-(prop-2-ynylthio)-1H-benzo[d]imidazoles and their corresponding hydrobromide salts under PdI2/KI-catalyzed oxidative aminocarbonylation conditions has been studied. It is found that 2-prop-2-ynylsulfanyl-3H-benzimidazolium salts, when allowed to react with amines, carbon monoxide, and oxygen, under the catalytic action of PdI2 (1mol%) in conjunction with KI (1equiv), under suitable conditions (80°C and 20atm of a 4:1 mixture of CO/air, in MeCN, and in the presence of a six-fold excess of amine, for 15h), could be selectively converted into 2-benzo[4,5]imidazo[2,1-b]thiazol-3-yl-N,N-dialkylacetamides in 60-78% yields, through an oxidative aminocarbonylation/heterocyclization process. The structure of a representative product, 2-benzo[4,5]imidazo[2,1-b]thiazol-3-yl-1-pyrrolidin-1-ylethanone, was confirmed by X-ray diffraction analysis.
benzimidazothiazoles; carbonylation; multicomponent reactions; palladium; synthetic methods
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: http://hdl.handle.net/20.500.11770/144529
 Attenzione

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

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 26
  • ???jsp.display-item.citation.isi??? 27
social impact