Nucleophile-dependent regio- and stereoselective ring opening of 1-azoniabicyclo[3.1.0]hexane tosylate.
1-[(1R)-(1-Phenylethyl)]-1-azoniabicyclo[3.1.0]hexane tosylate was generated as a stable bicyclic aziridinium salt from the corresponding 2-(3-hydroxypropyl)aziridine upon reaction with p-toluenesulfonyl anhydride. This bicyclic aziridinium ion was then treated with various nucleophiles including halides, azide, acetate, and cyanide in CH3CN to afford either piperidines or pyrrolidines through regio- and stereoselective ring opening, mediated by the characteristics of the applied nucleophile. On the basis of DFT calculations, ring-opening reactions under thermodynamic control yield piperidines, whereas reactions under kinetic control can yield both piperidines and pyrrolidines depending on the activation energies for both pathways.
Department of Chemistry, Hankuk University of Foreign Studies, Yongin, 449-791 (Korea).
Mi-Kyung
MK
Ji
Dietmar
D
Hertsen
Doo-Ha
DH
Yoon
Heesung
H
Eum
Hannelore
H
Goossens
Michel
M
Waroquier
Veronique
V
Van Speybroeck
Matthias
M
D'hooghe
Norbert
N
De Kimpe
Hyun-Joon
HJ
Ha
D001388:Aziridines / Q000737:chemistry; D001557:Benzenesulfonates / Q000737:chemistry*; D001643:Bridged Bicyclo Compounds / Q000737:chemistry*; D018360:Crystallography, X-Ray; D007700:Kinetics; D008968:Molecular Conformation; D010880:Piperidines / Q000737:chemistry; D013237:Stereoisomerism; D013816:Thermodynamics
C573194:4-methylbenzenesulfonic acid; D001388:Aziridines; D001557:Benzenesulfonates; D001643:Bridged Bicyclo Compounds; D010880:Piperidines; C046059:bicyclo(3.1.0)hexane; C033132:aziridine
aziridines; density functional theory calculations; heterocycles; nucleophilic substitution; ring expansion; ring opening