title: Microwave-assisted tandem organocatalytic peptide-coupling intramolecular aza-Michael reaction: α,β-unsaturated N-acyl pyrazoles as Michael acceptors.
abstract: Conjugated N-acyl pyrazoles have been successfully employed in the organocatalytic enantioselective intramolecular aza-Michael reaction as ester surrogates. Bifunctional squaramides under microwave irradiation provided the best results in this transformation. Furthermore, this protocol has been combined with a peptide-coupling reaction in a tandem sequence. The final products were easily converted into the corresponding ethyl esters.
authors.affiliation: Departamento de Química Orgánica, Universidad de Valencia, 46100-Burjassot (Spain); Centro de Investigación Príncipe Felipe, Laboratorio de Moléculas Orgánicas, 46012-Valencia (Spain).
authors.forename: María
authors.initials: M
authors.lastname: Sánchez-Roselló
authors.forename: Cristina
authors.initials: C
authors.lastname: Mulet
authors.forename: Marta
authors.initials: M
authors.lastname: Guerola
authors.forename: Carlos
authors.initials: C
authors.lastname: del Pozo
authors.forename: Santos
authors.initials: S
authors.lastname: Fustero
mesh_terms: D000577:Amides / Q000737:chemistry*; D002384:Catalysis; D004952:Esters; D008872:Microwaves; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D011720:Pyrazoles / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000577:Amides; D004952:Esters; D010455:Peptides; D011720:Pyrazoles
keywords: acyl pyrazoles; intramolecular aza-Michael reaction; organocatalysis; squaramides; tandem reactions