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The arylation of azaheterocycles can be considered as one of the most important processes for the preparation of various biologically active compounds.

A single-crystal X-ray diffraction (XRD) study of diaryliodonium tetrachloroaurates (or, in the recent terminology, tetrachloridoaurates), [(

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.

The direct N-arylation of cyclic amides can be considered a pivotal issue for modern organic chemistry. Here, we report the method for copper-catalyzed N-arylation of diverse oxadiazolones by diaryliodonium salts in mild conditions in high yields (up to 92%) using available CuI as a catalyst. The developed method allows to efficiently utilize both symmetric and unsymmetric diaryliodonium salts bearing auxiliary groups such as 2,4,6-trimethoxyphenyl (TMP). The evaluation of steric effects in aryl moieties to the chemoselectivity of N- and O-arylation of the 1,2,4-oxadiazol-5(4H)-ones exhibited the high potential of mesityl-substituted diaryliodonium salts as a selective arylation reagent. The structural study suggests that steric accessibility of N-atom in 1,2,4-oxadiazol-5(4H)-ones impact to arylation with sterically hindered diaryliodonium salts. The synthetic application of proposed method was also demonstrated on selective arylation of 1,3,4-oxadiazol-2(3H)-ones and 1,2,4-oxadiazole-5-thiol.

Three diaryliodonium tetrachloroaurates(III), [Ar1IAr2][AuCl4] (Ar1/Ar2 = Ph/Ph (1), Ph/Mes (2), o-(C6H4)2 (3)), were obtained as solids (62–80%) by the metathetical reaction of [Ar1IAr2](CF3CO2) a...

Hypervalent iodine(III)-derivatives display higher catalytic activity than other aliphatic and aromatic iodine(I)– or bromine(I)-containing substrates for a Knorr-type reaction of N-acetyl hydrazides with acetyl acetone to give N-acyl pyrazoles. The highest activity was observed for dibenziodolium triflate, for which 10 mol% resulted in the generation of N-acyl pyrazole from acyl hydrazide and acetyl acetone typically at 50 °C for 3.5–6 h with up to 99% isolated yields. 1H NMR titration data and DFT calculations indicate that the catalytic activity of the iodine(III) is caused by the binding with a ketone.

X-ray crystallography data revealed the dichotomy of thiocyanate-involving noncovalent interactions in [Ar1Ar2I](SCN), as reflected in the generation of two types of supramolecular aggregates: (i) previously unreported 4-membered heterotetramers (Ar1/Ar2 = 4-ClC6H4/2,4,6-(MeO)3C6H2, 4-BrC6H4/2,4,6-(MeO)3C6H2; 2 examples) featuring exclusively halogen bond (XB) N-XB-bound SCN− anions, and (ii) the 8-membered cyclic heterotetramers (Ar1/Ar2 = Ph/Ph, Ph/2,4,6-(MeO)3C6H2, 4-FC6H4/2,4,6-(MeO)3C6H2, 3,5-Me2C6H3/4-MeOC6H4, 3,5-Me2C6H3/2,4,6-(MeO)3C6H2; 5 examples) with two N,S-XB-bound thiocyanates featuring both S⋯I and N⋯I noncovalent contacts. In all cases, the IIII centers function as a double σ-hole donor to provide two directional XBs. The XB preorganization affects the chemoselectivity of the thiocyanate arylation in the solid-state: the heating of [Ar1Ar2I](SCN) exhibiting either N-, or N,S preorganized XBs leads to extremely rare N-arylation or the conventional S-arylation, respectively. The charge-assisted XBs in [Ar1Ar2I](SCN) were studied using density functional theory (DFT) calculations combined with a molecular electrostatic potential surface analysis and the quantum theory of atoms in molecules (QTAIM). Competition between the N- and N,S-XB interactions was studied, including the recognition of energy differences between the I⋯N and I⋯S contacts. The computational data were useful to rationalize the divergent solid-state N- or S-arylation of thiocyanates.

Reactions of 2-carbonyl- and 2-hydroxy(or methoxy)alkylbenzimidazoles with arenes in the Brønsted superacid TfOH resulted in the formation of the corresponding Friedel–Crafts reaction products, 2-diarylmethyl and 2-arylmethyl-substituted benzimidazoles, in yields up to 90%. The reaction intermediates, protonated species derived from starting benzimidazoles in TfOH, were thoroughly studied by means of NMR and DFT calculations and plausible reaction mechanisms are discussed.

Flow chemistry is considered to be a versatile and complementary methodology for the preparation of valuable organic compounds. We describe a straightforward approach for the synthesis of iodonium trifluoroacetates through the direct oxidation of iodoarenes in a simple flow reactor using an Oxone‐filled cartridge. Optimization has been carried out using the Nelder–Mead algorithm. The procedure allows a wide range of iodonium salts to be prepared from simple starting materials.

A ditriflate derivative of 2-iodoxybenzoic acid (IBX) was prepared by the reaction of IBX with trifluoromethanesulfonic acid and characterized by single crystal X-ray crystallography. IBX-ditriflate is the most powerful oxidant in a series of structurally similar IBX derivatives which is best illustrated by its ability to readily oxidize hydrocarbons and the oxidation resistant polyfluoroalcohols.

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.

A facile synthesis of diaryliodonium salts utilizing Oxone as versatile and cheap oxidant has been developed. This method shows wide applicability and can be used for the preparation of iodonium salts containing electron-donating or electron-withdrawing groups in good yields. In addition, this procedure can be applied to the preparation of symmetric iodonium salts directly from arenes via a one-pot iodination–oxidation sequence.

New substituted 1-arylbenziodoxolones were prepared and their reactivity with azide anion nucleophile was investigated. It was found that independent on the presence of substituents, all reactions of 1-arylbenziodoxolones proceed as nucleophilic substitution of the iodonium leaving group in the electron-deficient benziodoxolone benzene ring. The presence of bulky substituents in the ortho-position of the aryl ring slowers the reaction, while the presence of a moderately electron-withdrawing bromine substituent in the para-position to iodine in the benziodoxolone ring moderately increases the rate of substitution. The presence of a strongly electron-withdrawing nitro group in the para-position to iodine in the benziodoxolone ring dramatically increases the rate of substitution. These observations are in agreement with the electronic requirements for internal nucleophilic substitution in the benziodoxole ring. A quantum-chemical computational study of the possible reaction paths is in agreement with the observed effects of substituents on the reactivity of arylbenziodoxolones in this reaction.

A rare example of pentacoordinated silver(I) complex featured unconventional type of coordination of 8-phenylquinoline has been prepared. DFT calculations indicated that the silver(I) center forms two strong coordination bonds with the N atoms (21.8–29.8 kcal/mol) and an electrostatically provided bond with the triflate anion (the charges at the silver(I) center and the triflate O atom are estimated as +0.64 and −1.02 e, respectively). The coordination polyhedron is complemented by two semicoordination bonds with the C atoms of the phenyl rings (4.3–6.0 kcal/mol). These silver(I)–phenyl π-interactions are significantly stronger than such interactions observed previously for other systems exhibiting energy lower than 2 kcal/mol.

The crystal structure of the newly synthesized 4-methoxyphenyl(phenyl)iodonium thiocyanate, [PhI(4-C6H4OMe)](SCN), represents the first example of 16-membered cyclic heterooctamer formed by halogen bonding between the iodonium cation and SCN&ndash, Results of density functional theory (DFT) calculations followed by the topological analysis of the electron density distribution within the framework of the quantum theory of atoms in molecules (QTAIM) method at the &omega, B97XD/DZP-DKH level of theory reveal that energies of attractive intermolecular noncovalent interactions I&middot, &middot, S and I&middot, N (responsible for the formation of heterooctameric supramolecular clusters {PhI(4-C6H4OMe)}4&middot, {SCN}4 in the solid state structure of [PhI(4-C6H4OMe)](SCN)) vary from 0.9 to 8.5 kcal/mol.

Mild and efficient method for the preparation of iodylarenes by oxidation of iodoarenes with Oxone in aqueous acetonitrile at room temperature is described. This new procedure allows the preparation of various iodylarenes with electron-donating or electron-withdrawing substituents in the aromatic ring including the previously unknown 1,2-diiodylbenzene.

An efficient oxidation of iodoarenes to the corresponding iodylarenes is achieved without the need for any catalyst.

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.