DIASTEREOSELECTIVE (ETHOXYCARBONYL)DIFLUOROMETHYLATION OF CHIRAL IMIDE ENOLATES MEDIATED BY TRIETHYLBORANE

Authors
ISEKI K ASADA D TAKAHASHI M NAGAI T KOBAYASHI Y
Citation
K. Iseki et al., DIASTEREOSELECTIVE (ETHOXYCARBONYL)DIFLUOROMETHYLATION OF CHIRAL IMIDE ENOLATES MEDIATED BY TRIETHYLBORANE, Chemical and Pharmaceutical Bulletin, 44(7), 1996, pp. 1314-1317
Citations number
22
Categorie Soggetti
Pharmacology & Pharmacy",Chemistry
Journal title
Chemical and Pharmaceutical Bulletin → ACNP
ISSN journal
00092363
Volume
44
Issue
7
Year of publication
1996
Pages
1314 - 1317
Database
ISI
SICI code
0009-2363(1996)44:7<1314:D(OCI>2.0.ZU;2-P
Abstract
Triethylborane-mediated reactions of lithium enolates derived from chi ral N-acyloxazolidinones with ethyl difluoroiodoacetate allows easy ac cess to alpha-(ethoxycarbonyl)difluoromethylated carbosimides with goo d diastereomcric excess (86-->98% de). The stereochemistry of the (eth oxycarbonyl)difluoromethylated carbosimides indicates that the (ethoxy carbonyl)difluoromethyl radical generated from ethyl difluoroiodoaceta te and triethylborane reacts preferentially on the si face of the lith ium enolates.