L. Al-Momani, Anas Lataifeh
2013
Citations
0
Influential Citations
17
Citations
Journal
Inorganica Chimica Acta
Abstract
Abstract A series of mono- and disubstituted O -ferrocenoyl conjugates of 3- trans - and 4- trans- hydroxy- L -proline amino acids are synthesized. These conjugates are protected by tert- butloxycarbonyl ( Boc ) group at the N -terminus. The Boc removal of the ferrocene (Fc) hydroxy- L -proline conjugates affords a series of mono- and disubstituted Fc conjugates containing free amine at the N -terminus. These conjugates are characterized by NMR and IR spectroscopies as well as mass (MS) spectrometry. The catalytic properties of the free amine Fc conjugates toward aldol addition reaction are studied. The enantioselectivity of the aldol reaction products in acetone solvent is determined by the position of the N -atom in the proline residue with respect to the proline point of attachment to the Fc scaffold. The 4- trans- hydroxy- L -proline containing Fc catalyst favors the production of the R -isomer, while Fc catalysts containing 3- trans- hydroxy- L -proline favors the production of the S -isomer.