Dramatic Stereo- and Enantiodivergency in the Intermolecular Asymmetric Heck Reaction Catalyzed by Palladium Complexes with Cyclopropane-Based PHOX Ligands

A series of novel chiral phosphanyl-oxazoline (PHOX) ligands possessing a cyclopropyl backbone were synthesized. It was shown that introduction of a strained cyclic fragment in the ligand platform helped restrict conformational fluctuations of the metallacycle and provided the catalyst with marked steric effects. It was demonstrated that insignificant alterations in the ligand structure had a dramatic influence on the stereochemical outcome of the intermolecular asymmetric Heck reaction.