Iodine catalysis: A green alternative to transition metals in organic chemistry and technology

Iodine and compounds of iodine in higher oxidation states have emerged as versatile and environmentally benign reagents for organic chemistry. One of the most impressive recent achievements in this area has been the discovery of catalytic activity of iodine in numerous oxidative transformations leading to the formation of new Csingle bondO, Csingle bondN, and Csingle bondC bonds in organic compounds. These catalytic transformations in many cases are very similar to the transition metal-catalyzed reactions, but have the advantage of environmental sustainability and efficient utilization of natural resources. Iodine is an environmentally friendly and a relatively inexpensive element, which is currently underutilized in industrial applications. One of the main goals of this review is presenting to industrial researchers the benefits of using catalytic iodine in chemical technology as an environmentally sustainable alternative to transition metals. The present review summarizes catalytic applications of iodine and compounds of iodine in organic synthesis

Synthesis of polydicyclopentadiene using the Cp2TiCl2/Et2AlCl catalytic system and thin-layer oxidation of the polymer in air

The polymerization process of dicyclopentadiene using a multicomponent catalytic system based on bis(cyclopentadienyl)titanium dichloride and diethylaluminum chloride was studied. It was demonstrated that the application of an excess of the aluminum component leads to the formation of stable charged complexes of blue discoloration, which initiate cationic polymerization of dicyclopentadiene. Unstabilized thin layers of obtained polydicyclopentadiene undergo oxidation and structuring under atmospheric oxygen. Oxidation of polydicyclopentadiene films in air occurs slowly during several weeks and can be determined by the increase of carbonyl and hydroxyl adsorption bands in infrared spectra. Along with oxidation, cross-linking processes occur in polymers, which lead to a change in physical parameters of the layers, and more precisely to a decrease in the permeability of atmospheric oxygen through the layers. Consequently, this leads to the transition of the oxidation from a kinetic mode into a diffusive mode. Such structural changes do not occur in a polymer that was stabilized by adding an antioxidant

Facile One-Pot Synthesis of Diaryliodonium Salts from Arenes and Aryl Iodides with Oxone

A straightforward synthesis of diaryliodonium salts is achieved by using Oxone as the stoichiometric oxidant. Slow addition is the key to obtaining good yields and purities of the reaction products, which are highly useful reagents in many different areas of organic synthesis

The Foundations of the Development of Technologies of the Synthesis of Radiopharmaceuticals

The selection of precursors (for example chelating agents) and development of a technique of chemical modification of the target molecules retaining its ability to bind to specific receptors are very important in the synthesis of radiopharmaceuticals. As some important precursors for target radiopharmaceuticals omega-iodo-aliphatic carboxylic acids and their esters can be used. We have developed an environmentally safe process for producing omega-iodoaliphatic carboxylic acids and their esters of the available, inexpensive and low toxic aliphatic cyclic ketones. We proposed a new method for the synthesis of the chelating agents omega-thia- or (bis(2-hydroxyethyl)amino)- aliphatic carboxylic acids (chelate 1 and chelate 2), which was caused by the existing disadvantages in the existing methods. Thus, based on our method the precursors (chelates) with yield of over 70-90% on the final stage were synthesized, and then the high effectiveness in producing target radiopharmaceuticals using different biomolecules was showed. 99mTc-chelates complexes were prepared with radiochemical purity >91% and found to be stable at room temperature for six hours

In Vitro Evaluation of a Specific Radiochemical Compound Based on 99mTc-labeled DARPinG3 for Radionuclide Imaging of Tumors Overexpressing Her-2/neu

It is still necessary to search for new informative diagnostic methods to detect malignant tumors with overexpression of Her-2/neu, which are characterized by the aggressive course of the disease, rapid rate of tumor growth and low rates of relapse-free and overall survival. In recent years, the radioisotope techniques for detection of specific tumor targets have been developing actively. Purpose: to develop a chemically stable radiochemical compound for the targeted imaging of cells overexpressing Her-2/neu. Material and methods: The study was performed using 2 cell lines .The human breast adenocarcinoma HER2-overexpressing cell line BT-474 was chosen to detect specific binding. As a control, HER2-negative human breast adenocarcinoma MCF-7 was used. The human breast adenocarcinoma BT-474 and MCF-7 cell lines were seeded in chamber-slides at the density of 35,000 cells/ml in trypsin-EDTA (PanEco) medium and grown overnight at 37°C. After that both cell lines were washed with Phosphate buffered saline (PBS) and distributed into test tubes to 1 ml (5 millions cells in each). After adding 100 [mu]l (70 MBq) studied complex of 99mTc-DPAH-DARPinG3 was incubated for 40 min at +4°C. Washing was performed three times with buffer PBS and 5% Bovine Serum Albumin (BSA). The characteristics of the binding specificity of the test set with the HER-2/neu receptor were determined by direct radiometric and planar scintigraphy. Nonparametric Mann-Whitney test was used to assess the differences in the quantitative characteristics between groups. Results: The output of the labeled complex was more than 91%, with a radiochemical purity of more than 94%. When carrying out a visual scintigraphic assessment much greater intensity accumulation of radiotracer was observed in the studied cell culture surface receptor overexpressing Her-2/neu. The results of direct radiometric also showed higher accumulation of the radiopharmaceutical in the adenocarcinoma cell line BT-474 human breast cancer overexpressing Her-2/neu compared to the control group. Conclusion: The preclinical studies demonstrated a high in vitro stability of the study compound, as well as its accumulation in the cell group overexpressing Her-2/neu

The foundations of the development of technologies of the synthesis of radiopharmaceuticals

The selection of precursors (for example chelating agents) and development of a technique of chemical modification of the target molecules retaining its ability to bind to specific receptors are very important in the synthesis of radiopharmaceuticals. As some important precursors for target radiopharmaceuticals omega-iodo-aliphatic carboxylic acids and their esters can be used. We have developed an environmentally safe process for producing omega-iodoaliphatic carboxylic acids and their esters of the available, inexpensive and low toxic aliphatic cyclic ketones. We proposed a new method for the synthesis of the chelating agents omega-thia- or (bis(2-hydroxyethyl)amino)- aliphatic carboxylic acids (chelate 1 and chelate 2), which was caused by the existing disadvantages in the existing methods. Thus, based on our method the precursors (chelates) with yield of over 70-90% on the final stage were synthesized, and then the high effectiveness in producing target radiopharmaceuticals using different biomolecules was showed. 99mTc-chelates complexes were prepared with radiochemical purity >91% and found to be stable at room temperature for six hours