Cu(II)-aza(bisoxazoline)-catalyzed asymmetric benzoylations.
[reaction: see text] Racemic 1,2-diols and alpha-hydroxy carbonyl compounds can be asymmetrically benzoylated in a kinetic resolution in the presence of various Cu(II)-aza(bisoxazoline) catalysts. A novel bisbenzyl-substituted aza(bisoxazoline) ligand proved to be especially effective when immobilized on MeOPEG(5000), giving from 91 to > or = 99% ee in 37-49% yield for each of five sequential reactions.
Gissibl
Anja
A
Institut für Organische Chemie der Universität Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany.
Finn
M G
MG
Reiser
Oliver
O