Organocatalytic stereoselective additions of different nucleophiles to β-nitroacrylates have been investigated. A thiourea-based cinchona-derived bifunctional catalyst promotes the addition of 1,3-diketones to differently substituted nitroacrylates in modest to fair yields and up to 93% enantioselectivity. The 1,3 dicarbonyl functionality of the addition products was then used to synthesize enantiomerically enriched 3,4,5-trialkyl substituted pyrazoles via reaction with hydrazine. The stereoselective addition of N-methylindole to nitroacrylate was also preliminarily studied; the Friedel-Crafts alkylation was successfully organocatalyzed in the presence of an acid additive in very good yields and up to 53% enantioselectivity.
Stereoselective addition of 1,3-diketones to β-Nitroacrylates catalyzed by chiral metal-free bifunctional catalysts / E. Massolo, M. Benaglia, A. Palmieri, G. Celentano. - In: ASIAN JOURNAL OF ORGANIC CHEMISTRY. - ISSN 2193-5807. - 3:4(2014), pp. 416-420.
|Titolo:||Stereoselective addition of 1,3-diketones to β-Nitroacrylates catalyzed by chiral metal-free bifunctional catalysts|
BENAGLIA, MAURIZIO (Corresponding)
|Parole Chiave:||Cinchona alkaloids; Ketones; Nitroacrylates; Organocatalysis; Pyrazoles|
|Settore Scientifico Disciplinare:||Settore CHIM/06 - Chimica Organica|
|Data di pubblicazione:||2014|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1002/ajoc.201300246|
|Appare nelle tipologie:||01 - Articolo su periodico|