TRANSITION-METAL-CATALYZED ASYMMETRIC 1,3-DIPOLAR CYCLOADDITION REACTIONS BETWEEN ALKENES AND NITRONES

Authors
GOTHELF KV JORGENSEN KA
Citation
Kv. Gothelf et Ka. Jorgensen, TRANSITION-METAL-CATALYZED ASYMMETRIC 1,3-DIPOLAR CYCLOADDITION REACTIONS BETWEEN ALKENES AND NITRONES, Journal of organic chemistry, 59(19), 1994, pp. 5687-5691
Citations number
47
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
Journal of organic chemistry → ACNP
ISSN journal
00223263
Volume
59
Issue
19
Year of publication
1994
Pages
5687 - 5691
Database
ISI
SICI code
0022-3263(1994)59:19<5687:TA1CR>2.0.ZU;2-W
Abstract
A transition-metal-catalyze denantioselective 1,3-dipolar cycloadditio n reaction between alkenes and nitrones has been developed employing 1 0 mol % of a chiral titanium catalyst generated in situ from Ti(i-OPr) (2)Cl-2 and chiral diols. Diastereofacial discrimination in favor of t he exo isomer was achieved in up to a 95:5 ratio. Isoxazolidines with an optical purity of up to 62% ee are obtained from this reaction. By precipitation of a racemate of one of the isoxazolidines an optical pu rity of >95% ee is obtained.