Temperature-controlled switchable preparation of ferrocene bis(oxazoline-phosphine) ligands with different planar chiralities and their coordination behaviors

An interesting temperature-controlled switchable o,o′-dilithiation of chiral bisoxazoline ferrocene was developed for the preparation of three kinds of ferrocene bis(oxazoline-phosphine) ligands with different planar chiralities. Diastereoselectivities of more than 4.5/1 were obtained. As a result of their different planar chiralities, the ligands 1∼3 exhibit different coordination behaviors with PdCl2(MeCN)2.