title: Alpha-aminoester-derived imidazoles by 1,5-electrocyclization of azavinyl azomethine ylides.
abstract: An efficient and practical method for the preparation of alpha-imidazol-1-yl esters from 1,2-diaza-1,3-dienes (DDs), alpha-amino esters, and aldehydes is described. The overall sequence features a Michael-type conjugate addition between the alpha-amino ester and the DD, followed by iminium ion formation via condensation with the aldehyde and 1,5-electrocyclization of the resulting thermally generated azavinyl azomethine ylide to afford eventually alpha-imidazol-1-yl esters. Such a protocol allows access to enantiomerically pure imidazoles from optically pure alpha-amino esters.
authors.affiliation: Istituto di Chimica Organica, Università degli Studi di Urbino Carlo Bo, via I Maggetti 24, 61029 Urbino, Italy.
authors.forename: Orazio A
authors.initials: OA
authors.lastname: Attanasi
authors.forename: Emilia
authors.initials: E
authors.lastname: Caselli
authors.forename: Paolo
authors.initials: P
authors.lastname: Davoli
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Favi
authors.forename: Fabio
authors.initials: F
authors.lastname: Mantellini
authors.forename: Claudia
authors.initials: C
authors.lastname: Ori
authors.forename: Fabio
authors.initials: F
authors.lastname: Prati