One-pot organocatalytic tandem adol/polycyclization reactions between 1,3-dicarbonyl compounds and alpha,beta,gamma,de-unsaturated aldehydes for the straightforward assembly of cyclopenta[b]furan-type derivatives: New insight into the Knoevenagel reaction

RIVEIRA M. J.; MISCHNE M. P.

CHEMISTRY-A EUROPEAN JOURNAL

WILEY-V C H VERLAG GMBH

Lugar: Weinheim; Año: 2012 vol. 18 p. 2382 - 2388

0947-6539

A new cascade pathway viable for Knoevenagel chemistry that involves the coupling between 1,3-dicarbonyl systems and á,â,ã,ä-unsaturated aldehydes has been developed. The process comprises the combination of a classic aldol-type condensation and a rare spontaneous metal-free cycloisomerization, representing a convergent and innovative approach for the stereoselective synthesis of cyclopenta[b]furan-type derivatives. The scope and limitations with respect to both reaction partners and mechanistic features were investigated. Meaningfully, our study provides valuable guidance concerning the structural and electronic effects controlling the reactivity of conjugated polyene carbonyl systems.