title: Access to optically active 3-substituted piperidines by ring expansion of prolinols and derivatives.
abstract: The ring expansion of prolinols via an aziridinium intermediate gives C3-substituted piperidines in good yields and enantiomeric excess, the substituent at the C3 position being derived from the most reactive nucleophile in the reaction mixture. Depending on the nucleophile, the reaction proceeds under thermodynamic or kinetic control. The regioselectivity of attack of nucleophiles on the aziridinium intermediate depends on the nature of the substituents on the nitrogen atom and the C4 position of the starting prolinols.
authors.affiliation: Laboratoire de Chimie Organique, ESPCI ParisTech, CNRS, 10 rue Vauquelin 75231 Paris Cedex 05 (France), Fax: (+33) 1-40-79-46-60.
authors.forename: Domingo
authors.initials: D
authors.lastname: Gomez Pardo
authors.forename: Janine
authors.initials: J
authors.lastname: Cossy
mesh_terms: D003300:Copper / Q000737:chemistry; D010880:Piperidines / Q000138:chemical synthesis / Q000737:chemistry*; D011759:Pyrrolidines / Q000737:chemistry*; D011789:Quantum Theory; D013237:Stereoisomerism
chemical_list: D010880:Piperidines; D011759:Pyrrolidines; C010509:prolinol; D003300:Copper
keywords: enantioselectivity; piperidines; pyrrolidinols; rearrangements; ring expansion