3,3'-oxazolidinyl-substituted 2,2'-biphenyldiols: novel tropos ligands with a large induction on the chiral axis.
A novel type of bisphenol ligand is presented which provides high modularity. Chiral information is introduced in the 3,3'-positions as N-arenesulfonyl-1,3-oxazolidines inducing an unexpectedly high diastereoselectivity of up to 98:2 onto the chiral axis. The impact of each part of the molecule on the diastereomeric ratio is evaluated with extended variable-temperature (VT) NMR studies. A first example of application in asymmetric catalysis is given. [structure: see text]
Wünnemann
Stefan
S
Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster, Germany.
Fröhlich
Roland
R
Hoppe
Dieter
D