Iodonium salts in organic synthesis

Hypervalent iodine compounds have found wide practical application as versatile, efficient, and sustainable reagents for organic synthesis. The preparation and reactions of diaryliodonium, alkenyl(aryl)iodonium, alkynyl(aryl)iodonium, and alkyl(aryl)iodonium salts are overviewed. Application of these reagents allows mild and highly selective arylations, alkenylations, alkynylations, and alkylations of various organic and inorganic substrates in a facile and environmentally friendly manner. The lecture also summarizes the chemistry of iodonium ylides with emphasis on their synthetic applications. Iodonium ylides have found synthetic application as efficient carbene precursors, especially useful as reagents for cyclopropanation of alkenes and preparation of heterocyclic compounds. Recently iodonium ylides have been utilized as efficient reagents in the thiotrifluoromethylation and nucleophilic fluorination reactions. Also summarizes the applications of iodonium compounds in the rapidly developing field of Positron Emission Tomography (PET). Reactions ofdiaryliodonium salts with fluoride anion have found wide practical application in PET as a fast and convenient method for the introduction of the radioactive [18F]-fluoride into radiotracer molecules. The best synthetic methods for the preparation of iodonium precursors for PET are described, the mechanistic aspects of nucleophilic fluorination reaction are discussed, and specific examples of the preparation of PET radioligands are provided.This work was supported by a research grant from the Russian Science Foundation (RSF-16-13-10081-P)

Газовая атака, или Осторожно, газы!

The article contains the current understanding of gas communication in smooth muscle cells, the basic mechanisms of action of gaseous transmitters, analyzes the different views on the nature of the endothelial relaxing and endothelial hyperpolarizing factors. We discuss the controversial issues of the mechanisms of endothelium-dependent relaxation of vascular smooth muscle.В статье даются современные представления о газовой коммуникации в гладкомышечных клетках, рассмотрены основные механизмы действия газотрансмиттеров, анализируются различные взгляды на природу эндотелиального релаксирующего и эндотелиального гиперполяризующего факторов. Обсуждаются дискуссионные вопросы механизмов эндотелий-зависимого расслабления гладких мышц сосудов

Can Plasmon Change Reaction Path? : Decomposition of Unsymmetrical Iodonium Salts as an Organic Probe

Plasmon-assisted transformations of organic compounds represent a novel opportunity for conversion of light to chemical energy at room temperature. However, the mechanistic insights of interaction between plasmon energy and organic molecules is still under debate. Herein, we proposed a comprehensive study of the plasmon-assisted reaction mechanism using unsymmetric iodonium salts (ISs) as an organic probe. The experimental and theoretical analysis allow us to exclude the possible thermal effect or hot electron transfer. We found that plasmon interaction with unsymmetrical ISs led to the intramolecular excitation of electron followed by the regioselective cleavage of C–I bond with the formation of electron-rich radical species, which cannot be explained by the hot electron excitation or thermal effects. The high regioselectivity is explained by the direct excitation of electron to LUMO with the formation of a dissociative excited state according to quantum-chemical modeling, which provides novel opportunities for the fine control of reactivity using plasmon energy.Peer reviewe

Understanding and Exploitation of Neighboring Heteroatom Effect for the Mild N-arylation of Heterocycles with Diaryliodonium Salts under Aqueous Conditions: A Theoretical and Experimental Mechanistic Study.

The mechanism of arylation of N-heterocycles with unsymmetric diaryliodonium salts is elucidated. The fast and efficient N-arylation reaction is interpreted in terms of the bifunctionality of the substrate: The consecutive actions of properly oriented Lewis base and Brønsted acid centers in sufficient proximity result in the fast and efficient N-arylation. The mechanistic picture points to a promising synthetic strategy where suitably positioned nucleophilic and acidic centers enable functionalization, and it is tested experimentally

Zwitterionic iodonium species afford halogen bond-based porous organic frameworks

Porous architectures characterized by parallel channels arranged in honeycomb or rectangular patterns are identified in two polymorphic crystals of a zwitterionic 4-(aryliodonio)-benzenesulfonate. The channels are filled with disordered water molecules which can be reversibly removed on heating. Consistent with the remarkable strength and directionality of the halogen bonds (XBs) driving the crystal packing formation, the porous structure is stable and fully preserved on almost quantitative removal and readsorption of water. The porous systems described here are the first reported cases of one-component 3D organic frameworks whose assembly is driven by XB only (XOFs). These systems are a proof of concept for the ability of zwitterionic aryliodonium tectons in affording robust one-component 3D XOFs. The high directionality and strength of the XBs formed by these zwitterions and the geometrical constraints resulting from the tendency of their hypervalent iodine atoms to act as bidentate XB donors might be key factors in determining this ability

Контрастные препараты для ультразвукового исследования

Ultrasound examination is the integral component of diagnostic imaging and it is widely used method for medical visualization in Russian clinical medicine. Modern diagnostic imaging inseparably linked with use of contrast agents. Currently, the use of echo-contrast agents is a compulsory condition for patient's examination with constant improvement and development of new echo-contrast agents. In Russia these agents are not widely used due to insufficient duration contrast procedure and high cost of examination. However, during the last years there are factors promoting the development and introduction of echo-contrast agents into the national market.Ультразвуковое исследование является неотъемлемой составной частью современной лучевой диагностики и в отечественной клинической медицине относится к наиболее широко используемым методам медицинской визуализации. Современная лучевая диагностика неразрывно связана с использованием эхоконтрастных препаратов (ЭКП). На сегодняшний день в мировой клинической практике использование ЭКП при ультразвуковом исследовании стало обязательным условием исследований больных любого клинического профиля при постоянном совершенствовании и разработке новых ЭКП. В России ЭКП не получили распространения ввиду недостаточной продолжительности времени контрастирования в сочетании с высокой стоимостью исследования. Однако в течение последних лет появились факторы, способствующие разработке и внедрению ЭКП на отечественный рынок