Scope and limitations of chiral bis(oxazoline) ligands in the copper-catalysed asymmetric cyclopropanation of trisubstituted alkenes

Authors
Ostergaard, N Jensen, JF Tanner, D
Citation
N. Ostergaard et al., Scope and limitations of chiral bis(oxazoline) ligands in the copper-catalysed asymmetric cyclopropanation of trisubstituted alkenes, TETRAHEDRON, 57(28), 2001, pp. 6083-6088
Citations number
12
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
TETRAHEDRON
ISSN journal
00404020 → ACNP
Volume
57
Issue
28
Year of publication
2001
Pages
6083 - 6088
Database
ISI
SICI code
0040-4020(20010709)57:28<6083:SALOCB>2.0.ZU;2-W
Abstract
A series of derivatives of 3-methyl-2-buten-1-ol has been used to test the scope and limitations of the copper-catalysed asymmetric cyclopropanation o f trisubstituted alkenes by ethyl diazoacetate in the presence of C-2-symme tric bis(oxazoline) ligands. In the best case, a trans/cis ratio of 91:9, w ith 92% ee for the major isomer, was obtained from the reaction of the p-me thoxybenzoate derivative. The highest ee was 95%, for the trans isomer of a 80:20 diastereomer mixture (acetate derivative). (C) 2001 Elsevier Science Ltd. hll rights reserved.