Carbohydrates as building blocks of privileged ligands for multiphasic asymmetric catalysis

To combine the high chem. performance of asym. catalysis with the increasing need fo sustainability, a strategy is presented that involves the straightforward prepn. of "Trost"-like ligands suitable for application in multiphasic homogeneous catalysis. Ligands with coordinating functions (phosphinoamide-phosphinoester groups) as well as phase tags introduced on a D-glucose scaffold were prepd. and then examd. in the Pd-catalyzed asym. desymmetrization of meso-2-cyclopenten-1,4-diol biscarbamate. In line with our assumption, the performance of the catlyst system under traditional conditions is as high as that of the original Trost ligand, derived from trans-cyclohexanediamine, giving enantioselectivities of 98 % ee. Moreover, promising results were obsd. under multiphasic homogeneous conditions