P-chiral β-aminophosphine oxides vs. β-aminophosphines as auxiliaries for ruthenium catalysed enantioselective transfer hydrogenation of arylketones

Baysal

Turgut

2011

Section: Resultsmentioning

confidence: 99%

Applications of transition metal complexes containing aminophosphine ligand to transfer hydrogenation of ketones

Baysal

Turgut

2011

“…Furthermore, it is well known that the complex with sp 3 ‐hybribized nitrogens having NH bonds exhibits a higher reaction rate. On the other hand, the presence of the NH group in the ligands may enable stabilization of a six‐membered cyclic transition state by forming a hydrogen bond with the oxygen atom of ketones . In this context, complexes 1a , 1b , 2a and 2b were selected as catalysts, iso‐PrOH/NaOH as the reducing system, and acetophenone as a model substrate (Scheme ), and the results are listed in Table .…”

Section: Resultsmentioning

confidence: 99%

Novel cyclohexyl‐based aminophosphine ligands and use of their Ru(II) complexes in transfer hydrogenation of ketones

Kayan

Meri̇ç

et al. 2014

Two new aminophosphines – furfuryl‐(N‐dicyclohexylphosphino)amine, [Cy2PNHCH2–C4H3O] (1) and thiophene‐(N‐dicyclohexylphosphino)amine, [Cy2PNHCH2–C4H3S] (2) – were prepared by the reaction of chlorodicyclohexylphosphine with furfurylamine and thiophene‐2‐methylamine. Reaction of the aminophosphines with [Ru(η6‐p‐cymene)(μ‐Cl)Cl]2 or [Ru(η6‐benzene)(μ‐Cl)Cl]2 gave corresponding complexes [Ru(Cy2PNHCH2–C4H3O)(η6‐p‐cymene)Cl2] (1a), [Ru(Cy2PNHCH2–C4H3O)(η6‐benzene)Cl2] (1b), [Ru(Cy2PNHCH2–C4H3S)(η6‐p‐cymene)Cl2] (2a) and [Ru(Cy2PNHCH2–C4H3S)(η6‐benzene)Cl2] (2b), respectively, which are suitable catalyst precursors for the transfer hydrogenation of ketones. In particular, [Ru(Cy2PNHCH2–C4H3S)(η6‐benzene)Cl2] acts as a good catalyst, giving the corresponding alcohols in 98–99% yield in 30 min at 82 °C (up to time of flight ≤ 588 h−1). Copyright © 2014 John Wiley & Sons, Ltd.

“…The complex with sp 3 ‐hybribized nitrogen containing N―H bonds displays a higher reaction rate. On the other hand, the presence of an N―H group in the ligands makes it possible to stabilize a six‐membered cyclic transition state by forming a hydrogen bond with the oxygen atom of ketones . Therefore, these kinds of ligands are attractive and also widely used, especially in ruthenium, rhodium and iridium complexes, for catalytic transfer hydrogenation reactions …”

Section: Resultsmentioning

confidence: 99%

Rhodium‐catalyzed transfer hydrogenation with aminophosphines and analysis of electrical characteristics of rhodium(I) complex/n‐Si heterojunctions

Ocak

Rafikova

et al. 2014

A series of novel neutral mononuclear rhodium(I) complexes of the P-NH ligands have been prepared starting from [Rh(cod) Cl] 2 complex. Structural elucidation of the complexes was carried out by elemental analysis, IR and multinuclear NMR spectroscopic data. The complexes were applied to the transfer hydrogenation of acetophenone derivatives to 1-phenylethanol derivatives in the presence of 2-propanol as the hydrogen source. Catalytic studies showed that all complexes are also excellent catalyst precursors for transfer hydrogenation of aryl alkyl ketones in 0.1 M iso-PrOH solution. In particular, [Rh(cod)(PPh 2 NH-C 6 H 4 -4-CH(CH 3 ) 2 )Cl] acts as an excellent catalyst, giving the corresponding alcohols in excellent conversion up to 99% (turnover frequency ≤ 588 h À1 ). Furthermore, rhodium(I) complexes have been used in the formation of organic-inorganic heterojunction by forming their thin films on n-Si and evaporating Au on the films. It has been seen that the structures have rectifying properties. Their electrical properties have been analyzed with the help of currentvoltage measurements. Finally, it has been shown that the complexes can be used in the fabrication of temperature and light sensors.