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The first effective and simple method for the direct one-pot transformation of 2-, 3-, and 4-aminopyridines, 2,6-diaminopyridines, and 2-aminoquinoline into the corresponding pyridinyl and quinolinyl trifluoromethanesulfonates and tosylates in solvents was developed. The procedure involves diazotization of the heterocyclic amines with sodium nitrite in mixed hexane–DMSO or hexane–DMF solutions in the presence of trifluoromethanesulfonic acid or p -toluenesulfonic acid.

An environmentally friendly Matsuda–Heck reaction with arenediazonium tosylates has been developed for the first time. A range of alkenes was arylated in good to quantitative yields in water. The reaction is significantly accelerated when carried out under microwave heating. The arylation of haloalkylacrylates with diazonium salts has been implemented for the first time.

The first method for the direct one-pot transformation of aminopyridines into pyridinyl trifluoromethanesulfonates is developed. The procedure involves diazotization of aminopyridines with sodium nitrite in a DMSO paste in the presence of trifluoromethanesulfonic acid.

Aromatic azides are formed in high yield from arenediazonium tosylates and sodium azide in water at room temperature or from aromatic amines via diazotization in the presence of p-TsOH. Besides being experimentally simple, these methods do not require any metal catalysis and provide clean products without purification.

The conversion of a variety of anilines to the corresponding iodoarenes is achieved via treatment with nitrite-loaded ion exchange resin in the presence of TosOH.

Substituted aminopyridines can be directly transformed into the corresponding pyridinyl tosylates by sequential diazotation and tosylation of the substrates under solvent-free conditions.

Various substituted aryl halides are synthesized via arenediazonium tosylate salt intermediates in an environmentally friendly manner.

Bromination and chlorination of various aniline substrates is carried out under optimized conditions A) and proceeds via formation of arenediazonium tosylates.

A covenient method with I2/NO3 − or KI/NO3 − has been developed for the synthesis of α -iodo- β -nitroalkenes from alkynes.

The review systematises and summarises the oxidative methods for the synthesis of compounds with vicinal carbonyl functions. The oxidative reagents used for this purpose, their scope and limitations are discussed. The bibliography includes 307 references.

Alkylphenyl- and dialkylacetylenes are oxidized by the DMSO—PdCl2 or DMSO—Pd/C system to give the corresponding 1,2-diketones. Oxidation of these compounds, unlike that of diarylacetylenes, is less selective and is accompanied by the partial cleavage of triple bonds and formation of ketones, 1,3-diketones, and aromatic compounds as secondary condensation products.

Polycyclic aromatic hydrocarbons when treated with iodine monochloride in water solutions of sulfuric acid afford iodo- and chloroderivatives. Biphenyl, fluorene, acenaphthene, 1-nitronaphthalene undergo iodination. Naphthalene furnishes a mixture of iodo- and chloroderivatives, prevailing the latter. Anthracene and phenanthrene provide only chlorinated products. The iodine monochloride in the sulfuric acid is a stronger iodinating agent than in acetonitrile.

The reaction with a-methylstyrene (VIII) was less selective and afforded in 70% overall yield an inseparable mixture of two isomers IX and X in 75 : 25 ratio according to GC-MS and H NMR data. The formation of reaction product X is an evidence of a contribution from free-radical chlorination of the methyl group in compound IX [or in initial a-methylstyrene (VIII)] effected by PhICl2. It turned out that reaction of styrene (II) with PhICl2 in methanol in the presence of iodine took another route easily providing a product of iodomethoxylation of the double bond XI in 80% yield. Obviously here the iodosobenzene dichloride acted as oxidant for iodine providing its electrophilic intermediates (I + , ICl, or CH3OI). This reaction is perhaps the first example of a simple iodoalkoxylation of alkenes with the use of compounds of polyvalent iodine, and it opens new opportunities for the synthesis of commonly less available iodoalkoxyalkanes [4, 5].

One of the most widely used methods of synthesis of aromatic iodides is based on diazotization–iodina-tion of aromatic amines. The diazotization is generally carried out using accessible sodium nitrite in strongly acidic medium at reduced temperature [1–5]. Alter-native procedures involve more expensive alkyl nitrites as diazotizing agents in the presence of diiodomethane or other sources of iodine [6, 7]. We previously pro-posed simple procedures for diazotization–iodination with sodium nitrite at room temperature in weakly acidic media created by

A new, simple, and effective method for the diazotization of a wide range of arylamines has been developed by using a polymer-supported diazotization agent in the presence of p-toluenesulfonic acid. Various pure arenediazonium tosylates with unusual stabilities can be easily prepared by this method. As a result, these salts are useful and versatile substrates for subsequent transformations, such as halogenation and Heck-type reactions. The unusual stabilities of arenediazonium tosylates are also preliminarily discussed with their X-ray structures.

In the middle of the past century several methods for the generation of I3 ion by reaction of iodine with oxidants in oleum or sulfuric acid were proposed and studied [1, 2]. It was shown that triodine cation in solution exhibits enhanced electrophilicity and that they are capable of iodinating benzene derivatives having electron-withdrawing substituents [3, 4]. On the basis of spectral data and quantum-chemical calculations we previously presumed [5–9] that dissolution of N-iodo imides in sulfuric acid could give rise to triodine cation I3 together with iodine(I) hydrogen sulfate (IOSO3H). With a view to get additional support to the above assumption we made an attempt to obtain a solution of I3 by reaction of tetra-N-iodoglycoluril (I, 1,3,4,6-tetraiodoperhydroimidazo[4,5-d]imidazole-2,5-dione) with iodine in sulfuric acid. As a result, we have developed an effective alternative way for the generation of I3. A solution containing I3 is readily formed by gradually adding compound I to a suspension of finely ground iodine in sulfuric acid (d = 1.815–1.834 g/cm) under stirring at 0–3°C (Scheme 1).

In contrast to published results, tetraalkylammonium dichloroiodates (Alk 4 N + ICl 2 - ) cannot be iodinating reagents for arenes- in solvent-free conditions. Nevertheless, tetraalkylammonium dichloroiodates in sulfuric acid solutions or in the presence of Ag 2 SO 4 in H 2 SO 4 possess superelectrophilic properties and act as very convenient and efficient iodinating agents for deactivated arenes-.

The diazotization of aryl amines at room temperature in paste form with NaNO 2 , p -TsOH and a small amount of water, followed by treatment with KI provides a new, simple, and effective route for the preparation of various aryl iodides. The water-paste and strong acid-free reaction conditions are environmentally friendly and compatible with acid-sensitive functional groups.

A convenient and simple one-pot method for the preparation of iodoarenes at room temperature has been developed, by sequential diazotization-iodination of aromatic amines with NaNO 2 /KI in the presence of a sulfonic acid based cation-exchange resin in water. This inexpensive, noncorrosive and eco-friendly synthetic route is general in nature and allows for the preparation of iodo-arenes with an electron-donating or -withdrawing group in various positions from the corresponding amines in 50-98% yields.

1,3-Diiodo-5,5-dimethylhydantoin in organic solvents successfully iodinates alkylbenzenes, aromatic amines, and phenyl ethers. The reactivity of electrophilic iodine is controlled by acidity of the medium. Superelectrophilic iodine generated upon dissolution of 1,3-diiodo-5,5-dimethylhydantoin in sulfuric acid readily reacts with electron-deficient arenes at 0 to 20°C with formation of the corresponding iodo derivatives in good yields. The structure of electrophilic iodine species generated from 1,3-diiodo-5,5-dimethylhydantoin in sulfuric acid is discussed.