The synthesis of enantiomerically pure, distally-bridged resorcinarenes 3 with various R groups (CH3, C5H11, C-11 H-23) is reported. The key step makes use of the Mannich reaction for attachment of a chiral diamine-line 2 across the cavity. Yields for this step are good to excellent. One of the bridged compounds exhibits modest activity (27% ee) as an enantioselective catalyst in the addition of diethylzinc to benzaldehyde.
- bridged resorcinarene
- chiral resorcinarene.
- Mannich reaction
- enantioselective catalyst
- C-2v-symmetric diamine chiral auxiliary
- CALIX<4>RESORCINARENE DERIVATIVES
- SELECTIVE DERIVATIZATION