Synthesis and characterization of ferrocene based chiral phosphinite compounds and their transition metal complexes and investigation of their catalytic activity

Asymmetric catalysis has become a growing field of study as the demand for more enantiomerically pure compounds arises. Asymmetric catalysis requires that a chiral catalyst be used in order to transfer its chirality to the substrate. An effective asymmetric catalyst will quickly produce a chiral product in good yield with high enantiomeric purity of the desired enantiomer.Compounds containing chiral metallocene ligands, in particular chiral ferrocenyl ligands, are one of the class of asymmetric catalysts that has received significant attention in recent years due to the versatility of these catalysts in a variety of applications. The ferrocenyl group has been widely explored in different areas, from polymers to bioorganometallic chemistry. Among several applications, the use of ferrocene-based chiral ligands in asymmetric synthesis is the most prominent.Ferrocene-based aminophosphine ligands have been shown to be effective in the ruthenium(II)-catalysed asymmetric transfer hydrogenation of ketones. The enantioselectivity mainly determined by the C-centred chirality of the ligands but the planar chirality is also important. Ferrocenyl iminodiphosphine ligands are also effective for the asymmetric transfer hydrogenation of methyl aryl ketones. Although some ferrocenyl aminoalcohols, aminophosphines and phosphines have been employed successfully as ligands in Ruthenium(II)-promoted transfer hydrogenation of ketones, a screening of catalytic activity of ferrocenyl phosphinites in this reaction is not yet reported.In this study, feerrocene-based chiral alcohols were prepared from the condensation of ferrocenealdehyde with various amino alcohols. The novel phosphinite compounds were synthesized by the reaction of these ferrocene-based chiral alcohols with Ph2PCl. Ru(II) complexes of the obtained phosphinite ligands were synthesized and fully characterized. Finally use of the Ru(II) complexes as catalysts in asymmetric transfer hydrogenation reactions of acetophenone were investigated.