title: [3,3]-Sigmatropic Rearrangement/Allylboration/Cyclization Sequence: Enantioenriched Seven-Membered-Ring Carbamates and Ring Contraction to Pyrrolidines.
abstract: The combination of in situ generated α-isocyanato allylboronic esters and aldehydes afforded seven-membered-ring enecarbamates with high levels of diastereo- and enantiocontrol. They were easily converted into diversely substituted 1,3-oxazepan-2-ones. An unprecedented rearrangement of 5-acetoxy-7-aryl or styryl derivatives led to tetrasubstituted pyrrolidines. A computational study provides evidence on the feasibility of the proposed mechanism of this unusual ring contraction.
authors.affiliation: Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, Campus de Beaulieu, 35042, Rennes Cedex, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Macé
authors.affiliation: Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, Campus de Beaulieu, 35042, Rennes Cedex, France.|AdPueriVitam, Laboratoire BioCIS, Faculté de Pharmacie, Université Paris-Sud, 5 rue J-B Clément, 92296, Châtenay-Malabry, France.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Touchet
authors.affiliation: Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, Campus de Beaulieu, 35042, Rennes Cedex, France.|Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: Andres
authors.affiliation: Departamento de Química Orgánica I, Facultad de Química, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Donostia International Physics Center (DIPC), P° Manuel Lardizabal 3, 20018, San Sebastián/Donostia, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Cossío
authors.affiliation: Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, Campus de Beaulieu, 35042, Rennes Cedex, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Dorcet
authors.affiliation: Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, Campus de Beaulieu, 35042, Rennes Cedex, France. francois.carreaux@univ-rennes1.fr.
authors.forename: François
authors.initials: F
authors.lastname: Carreaux
authors.affiliation: Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, Campus de Beaulieu, 35042, Rennes Cedex, France. bertrand.carboni@univ-rennes1.fr.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Carboni
keywords: allylic compounds; asymmetric synthesis; heterocycles; reaction mechanisms; rearrangements