Ru(II) pyridyl-based NNN complex catalysts for (asymmetric) transfer hydrogenation of ketones at room temperature

Asymmetric Transfer Hydrogenation of Arylketones Catalyzed by Enantiopure Ruthenium(II)/Pybox Complexes Containing Achiral Phosphonite and Phosphinite Ligands

A family of complexes of the formula trans-[RuCl₂(L)(R-pybox)] (R-pybox = (S,S)-ⁱPr-pybox, (R,R)-Ph-pybox, L = monodentate phosphonite, PPh(OR)₂, and phosphinite, L = PPh₂(OR), ligands) were screened in the catalytic asymmetric transfer hydrogenation of acetophenone, observing a strong influence of the nature of both the R-pybox substituents and the L ligand in the process. The best results were obtained with complex trans-[RuCl₂{PPh₂(OEt)}{(R,R)-Ph-pybox}] (2c), which provided high conversion and enantioselectivity (up to 96% enantiomeric excess, e.e.) for the reduction of a variety of aromatic ketones, affording the (S)-benzylalcohols.

Ruthenium(II) complexes bearing (NNN) ligand: catalytic evaluation of different solvent-mediated coordination modes

A new (NNN) tridentate ligand was prepared, and its ability to coordinate ruthenium(II) was evaluated. The presence of different functional groups on the ligand allows bi- or tri-coordinated complexes to be obtained depending on complexation conditions. The catalytic activity of both bidentate and tridentate complexes was studied in asymmetric transfer hydrogenation of different aryl ketones, showing a comparable behavior of the two complexes in terms of efficiency and stereoselectivity.

Cu(II) complex of pyridine-based polydentate as a novel, efficient, and highly reusable catalyst in C-N bond-forming reaction

In this paper, a highly reusable copper(II) complex of pyridine-based polydentate is able to efficiently catalyze a C-N bond-forming reaction under mild conditions. A variety of N-heterocyclic and amine compounds arylated with different aryl iodides, bromides, and chlorides produced N-substituted compounds in good to excellent yields. This methodology can be also used for the arylation of N-unsubstituted compounds using arylboronic acids under solvent-free conditions. All reactions are performed in short times under air, and the catalyst can be reused up to seven times.

Synthesis of single-enantiomer bioactive molecules: a brief overview

Chiral-center enantiomers have been shown to differ significantly in biological activity, pharmacodynamics, pharmacokinetics and toxicity. New developments in the stereoselective organic synthesis have enriched the vast literature of synthetic methodologies applicable to access natural products as well as bioactive molecules. These compounds also include new drugs, drug candidates and reagents used to explore biological processes. The article reviews the synthesis of optically pure drugs, biologically active intermediates and amino alcohols by using different methods.