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Wittig-type olefination catalyzed by PEG-telluride.
- Source :
-
The Journal of organic chemistry [J Org Chem] 2002 May 03; Vol. 67 (9), pp. 3096-103. - Publication Year :
- 2002
-
Abstract
- Soluble poly(ethylene glycol) (PEG)-supported telluride 2 was designed and synthesized for catalytic Wittig-type reactions. It was found that the catalytic loading could be reduced from 20 to 2 mol % by the introduction of PEG (even to 0.5 mol % when some telluride salts were used as the catalyst). Under the catalytic reaction conditions, a wide variety of aldehydes with different structures could react with bromoacetate to afford beta-substituted or alpha,beta-disubstituted unsaturated esters in high yields with excellent E-stereoselectivity. The modified process, by using sodium bisulfite instead of triphenyl phosphite, represented a very simple product isolation procedure. The roles of PEG for promoting the ylide formation and stabilizing the catalytic species were disclosed. The mechanism was also studied.
Details
- Language :
- English
- ISSN :
- 0022-3263
- Volume :
- 67
- Issue :
- 9
- Database :
- MEDLINE
- Journal :
- The Journal of organic chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 11975572
- Full Text :
- https://doi.org/10.1021/jo025586h