Stereoselective oxidation of 4-aryl-1,4-dihydropyridines to axially chiral4-arylpyridines with 2,2,6,6-tetramethyl-1-oxopiperidinium tetrafluoroborate (TEMPO+BF4-)

Authors
Koop, B Straub, A Schafer, HJ
Citation
B. Koop et al., Stereoselective oxidation of 4-aryl-1,4-dihydropyridines to axially chiral4-arylpyridines with 2,2,6,6-tetramethyl-1-oxopiperidinium tetrafluoroborate (TEMPO+BF4-), TETRAHEDR-A, 12(2), 2001, pp. 341-345
Citations number
21
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
TETRAHEDRON-ASYMMETRY
ISSN journal
09574166 → ACNP
Volume
12
Issue
2
Year of publication
2001
Pages
341 - 345
Database
ISI
SICI code
0957-4166(20010219)12:2<341:SOO4TA>2.0.ZU;2-E
Abstract
Enantiopure 4-aryl-1,4-dihydropyridines (DHPs) were oxidised with 2,2,6,6-t etramethyl-1-oxopiperidinium tetra-fluoroborate I to axially chiral 4-arylp yridines with excellent yields and high enantiomeric excesses. The results can be rationalised via a hydride abstraction of 1 at C-(4) of the DHP from the less sterically shielded ap-conformer. (C) 2001 Elsevier Science Ltd. All rights reserved.