title: Nonbonded, attractive cation-pi interactions in azide-mediated asymmetric ring expansion reactions.
abstract: The influence of attractive, nonbonded interactions on the reactions of 1,2- and 1,3-hydroxyalkyl azides with ketones has been investigated through experimental and computational means. A series of 1,3-hydroxyalkyl azides bearing electronically tuned aromatic groups at the 2 position were prepared and reacted along with several derivatives designed to conformationally restrict the rotational orientation of the aromatic substituent. These studies showed that a cation-pi interaction between an aryl moiety and an N2(+) leaving group plays a role in determining the stereoselectivity of these reactions. A series of ab initio calculations supported this hypothesis. A computational and experimental analysis suggested a primarily steric model for the analogous reactions of substituted 2-azido-1-ethanol analogues.
authors.affiliation: Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Room 2010, Malott Hall, Lawrence, Kansas 66045-7582, USA.
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Katz
authors.forename: Timothy
authors.initials: T
authors.lastname: Ribelin
authors.forename: Donna
authors.initials: D
authors.lastname: Withrow
authors.forename: Yashar
authors.initials: Y
authors.lastname: Basseri
authors.forename: Anna K
authors.initials: AK
authors.lastname: Manukyan
authors.forename: Amy
authors.initials: A
authors.lastname: Bermudez
authors.forename: Christian G
authors.initials: CG
authors.lastname: Nuera
authors.forename: Victor W
authors.initials: VW
authors.lastname: Day
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Powell
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Poutsma
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Aubé
mesh_terms: D000478:Alkylation; D001386:Azides / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry; D002412:Cations / Q000737:chemistry; D003500:Cyclization; D000431:Ethanol / Q000737:chemistry; D005740:Gases / Q000737:chemistry; D006900:Hydroxylation; D015394:Molecular Structure; D011407:Propane / Q000737:chemistry; D012997:Solvents; D013237:Stereoisomerism
chemical_list: D001386:Azides; D002412:Cations; D005740:Gases; D012997:Solvents; D000431:Ethanol; D002244:Carbon; D011407:Propane