Asymmetric isomerisation of a cyclic diene: a comparative study of BINAP and BIPNOR-rhodium(I) catalysts

Authors
Faitg, T Soulie, J Lallemand, JY Mercier, F Mathey, F
Citation
T. Faitg et al., Asymmetric isomerisation of a cyclic diene: a comparative study of BINAP and BIPNOR-rhodium(I) catalysts, TETRAHEDRON, 56(1), 2000, pp. 101-104
Citations number
11
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
TETRAHEDRON
ISSN journal
00404020 → ACNP
Volume
56
Issue
1
Year of publication
2000
Pages
101 - 104
Database
ISI
SICI code
0040-4020(20000101)56:1<101:AIOACD>2.0.ZU;2-R
Abstract
The asymmetric isomerisation of 5,7-dibenzyloxy-6-(triallcylsilyloxy) cyclo hepta-1,3-diene 1 to the corresponding 1,6-dibenzyloxy-7-(triallcylsilyloxy ) cyclohepta-1,3-diene 2 can be accomplished at 90 degrees C in a 75/25 mix ture of toluene and DME in the presence of a [Rh(BIPNOR)(cod)](+) catalyst with 92% ee. A much lower ee is observed with BINAP. In both cases, the obs erved ee's increase with temperature. A mechanism involving an eta(5)-penta dienyl-rhodium complex is proposed. (C) 1999 Elsevier Science Ltd. All righ ts reserved.