An alternative route to tethered Ru(II) transfer hydrogenation catalysts

Ru-TsDPEN catalysts and derivatives in asymmetric transfer hydrogenation reactions

This review summarizes current developments, novel synthetic routes for Ruthenium tethered chiral catalyst, and its derivatives along with its application in asymmetric synthesis. The review also covers derivatization in tethering unit, modification in N-monofunctionalized ligand as well as ligation of other ligand with Ru metal in chiral catalyst. Apparently, the effect of a modified tethered catalyst in the enantioselective synthesis of chiral products as well as in synthetic chemistry is also discussed in detail.

Accessible Bifunctional Oxy-Tethered Ruthenium(II) Catalysts for Asymmetric Transfer Hydrogenation

A concise synthesis of new oxy-tethered ruthenium complexes effective for the asymmetric transfer hydrogenation of aromatic ketones is described. The oxy-tether was constructed via a defluorinative etherification arising from an intramolecular nucleophilic substitution of a perfluorinated phenylsulfonyl substituent. The obtained tethered complexes exhibited desirable catalytic activity and selectivity, especially in the asymmetric transfer hydrogenation of functionalized aromatic ketones. The robustness and rigidity of the tether contribute to their superior catalytic performance relative to the nontethered prototype complex.