Nonbonded, attractive cation-pi interactions in azide-mediated asymmetric ring expansion reactions.
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.
Katz
Christopher E
CE
Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Room 2010, Malott Hall, Lawrence, Kansas 66045-7582, USA.
Ribelin
Timothy
T
Withrow
Donna
D
Basseri
Yashar
Y
Manukyan
Anna K
AK
Bermudez
Amy
A
Nuera
Christian G
CG
Day
Victor W
VW
Powell
Douglas R
DR
Poutsma
Jennifer L
JL
Aubé
Jeffrey
J
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
D001386:Azides; D002412:Cations; D005740:Gases; D012997:Solvents; D000431:Ethanol; D002244:Carbon; D011407:Propane