METAL COMPLEX CATALYSIS

Complexes of transition metals with chiral ligands are considered as catalysts. Among metal-containing organic complexes with semiconducting properties, compounds of the porphin series occupy a special place in electrocatalytic studies. The properties of the porphyrin macrocycle, their role in catalysis, and the influence of the nature of the metal on the catalytic properties of the complex are considered.

Asymmetric Organocatalyzed Warfarin Synthesis in aqueous and nonaqueous media: A discussion in the era of COVID-19 pandemic

: The recent widespread infection of COVID-19 in the entire world has created pandemic situation with a serious health challenge to the mankind. Numerous incidents of cardiovascular disease were found among COVID-19 patients with a significantly high morbidity rate. Medication with several anticoagulant or blood thinner drugs are being performed on COVID-19 patients with atrial fibrillation and cardiovascular ailments to minimize the incidence of death. Warfarin is widely used anticoagulant and cardiovascular drug prescribed as its sodium salt. S-Enantiomer is two to five times more active than R-enantiomer as anticoagulant. Synthesis of enantiomerically pure warfarin is thus a rational and extremely important task. Organocatalyzed synthetic strategies may be considered as important avenues to produce optically pure warfarin in comparison to biocatalysis and chiral metal complex catalysis. Herein, a comprehensive review on the asymmetric organocatalyzed synthesis of warfarin catalysed by diamine based organocatalysts, amino acid based organocatalysts, quinine based organocatalysts and proline derived organocatalysts in both aqueous and non-aqueous media has been discussed.

Applications of Bolm’s Ligand in Enantioselective Synthesis

One pathway for the preparation of enantiomerically pure compounds from prochiral substrates is the use of metal complex catalysis with chiral ligands. Compared to the other frequently used chiral ligands, chiral 2,2’-bipyridines have been underexploited, despite the data indicating that such ligands have considerable potential in synthetic chemistry. One of those is the so-called Bolm’s ligand, a compound possessing chiral alcohol moieties in the side chains attached to the 2,2’-bipyridine scaffold. Various metal salts have been used in combination with Bolm’s ligand as potent catalysts able to bring about enantioselective alkylations, allylations, conjugate additions, desymmetrization of meso-epoxides, aldol reactions, etc. This review aims to summarize Bolm’s ligand applications in the area of enantioselective synthesis over the last three decades since its preparation.

Synthesis, Characterization, and Catalytic Activity of Palladium-polyvinylpyrrolidone Complex in Oxidation of Octene-1

The metal complex catalysis with participation of unsaturated hydrocarbons gains great interest because of ecological aspect and a possibility of re-using of the catalyst. It has a number of advantages in comparison with a heterogeneous catalysis, such as high activity and selectivity, low temperatures of reaction and pressure. A palladium-polyvinylpyrrolidone complex was synthesized and characterized by potentiometry, conductometry, mass-, and IR-spectroscopy. The complex was tested for catalytic activity in reaction of octene-1 oxidation by inorganic oxidizers (KIO4, NaBrO3, Na2S2O8, K2S2O8) in dimethylsulfoxide or dimethylformamide under mild conditions. The reaction product was octanone-2, obtained in good yield (80-98 %) and characterized by gas chromatography and mass spectrometry. The catalysts can be easily recycled five consecutive runs without significant loss of catalytic efficiency. The use of different surface analysis techniques, such as: Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray spectroscopy (EDX), led to a better understanding of the polymer promoting effect. Copyright © 2018 BCREC Group. All rights reservedReceived: 18th December 2017; Revised: 6th August 2018; Accepted: 9th August 2018How to Cite: Akbayeva, D.N., Bakirova, B.S., Seilkhanova, G.A., Sitzmann, H. (2018). Synthesis, Characterization, and Catalytic Activity of Palladium-polyvinylpyrrolidone Complex in Oxidation of Octene-1. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (3): 560- 572 (doi:10.9767/bcrec.13.3.1980.560-572)Permalink/DOI: https://doi.org/10.9767/bcrec.13.3.1980.560-572