Chiral Polysiloxane-Fixed Metal 1,3-Diketonates (Chirasil-Metals) as Catalytic Lewis Acids for a Hetero Diels-Alder Reaction -Inversion of Enantioselectivity Upon Catalyst -Polymer Binding
✍ Scribed by Keller, Fritz ;Weinmann, Hilmar ;Schurig, Volker
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1997
- Tongue
- English
- Weight
- 665 KB
- Volume
- 130
- Category
- Article
- ISSN
- 0009-2940
No coin nor oath required. For personal study only.
✦ Synopsis
catalysis I Cycloadditions I Lewis acids I Polymers A dimethylpolysiloxane chain is covalently bound to the monomeric Lewis acid catalyst (1R)-(+)-oxovanadium(1V) bis[3heptafluorobutanoylcamphorate] [ (+)-5a] at the C-10 position of the camphor moiety yielding the novel chiral polymeric (1s)-( +)-oxovanadium(1V) bis[3-Iieptafluorobut.anoylcamphordte] -dimethylpolysiloxane [ ( +)-6a]111. The Lewis acid promoted hetero Diels-Alder reaction of trans-l-methoxy-3-(trimethylsily1oxy)-1,3-butadiene (1) and benzaldehyde (2) is studied in the presence of the enantiomerically pure monomeric (5a, 5b) and polymeric (6a, 6b) catalysts. The rnonomeric and polymeric catalysts of identical chirality['] invoke op-0009-294019710707-0879 S 17.50+.5010 879 ' ' 1