trans-(2R,3R)-2,3-Diphenylcyclopropane-1,1-dimethanol: a pivotal diol for the synthesis of novel C2-symmetric ligands for asymmetric transition metal catalysis

Various chiral ligands bearing phosphorus or nitrogen donor atoms were obtained in a straightforward manner starting from trans-(2R,3R)-diphenylcyclopropane-1,1-dimethanol as a key structure. These chiral ligands were tested and compared in palladium(0)-catalyzed asymmetric allylic alkylation reactions (up to 71% ee) and rhodium(1)-catalyzed asymmetric hydrogenations (up to 88% ee). Moreover, in the asymmetric allylic alkylation, we observed excellent activity with a diphosphinite ligand (TOF = 600 mol 17 x [mol Pd x h)(-1)]. (C) 2010 Elsevier Ltd. All rights reserved.