Recent Progress in the Chemistry of 2-Tosylacetonitrile

This review is a broad overview of the chemistry of 2-tosylacetonitrile, which considered as a very reactive synthetic compound. The synthetic methods are reported. The reactions of the title compound lead to the preparation of a variety of heterocyclic ring systems, such as five- and six-membered ring systems containing one, two, or three heteroatoms. The reaction mechanisms are discussed.     

A Novel Tandem Reaction for the Synthesis of Fused Pyrazoles

Some of the fused heterocyclic compounds are important pharmaceuticals and agrochemicals. Study on their synthetic methodology is also very important in heterocyclic chemistry. The synthesises of 1H-pyrazole[5,1-b]thiazole^[1-2] and lH-thieno[2,3-c]pyrazole^[3-5] were reported by fewer literatures.     

3-Phenylcoumarins as a Privileged Scaffold in Medicinal Chemistry: The Landmarks of the Past Decade

3-Phenylcoumarins are a family of heterocyclic molecules that are widely used in both organic and medicinal chemistry. In this overview, research on this scaffold, since 2010, is included and discussed, focusing on aspects related to its natural origin, synthetic procedures and pharmacological applications. This review paper is based on the most relevant literature related to the role of 3-phenylcoumarins in the design of new drug candidates. The references presented in this review have been collected from multiple electronic databases, including SciFinder, Pubmed and Mendeley.     

Novel Approaches to the Synthesis of Some Heterocycles Containing Nitrogen

Some syntheses of heretofore unknown pyrimidines, tetrahydroquinazolines, and quinazolines are described. These methods are uniquely simple one- or two-step reactions, general and versatile in scope, and give high yields. Some interesting chemistry associated with these heterocyclic systems is discussed.     

An IETS study of the adsorption of 2,3-dihydroxynaphthalene, 1,2-dihydroxybenzene, 1,3-dihydroxybenzene and 1,4-dihydroxybenzene on thin-film plasma-grown aluminium and magnesium oxides

Inelastic Electron Tunnelling Spectroscopy (IETs) has been applied to study the adsorption of 2,3-dihydroxynaphthalene, 1,2-dihydroxybenzene, 1,3-dihydroxybenzene and 1,4-dihydroxybenzene onto plasma-grown thin-film partially hydroxylated magnesium and aluminium oxides. For both 2,3-dihydroxynaphthalene and 1,2-dihydroxybenzene on aluminium oxide it is found that adsorbate chemisorption involves reaction of the two hydroxyl groups present in the adsorbate to form a di-anion in the case of the former and both the mono- and di-anion for the latter. The tunnel spectra for both compounds on magnesium oxide indicate that the di-anion is formed. Adsorption at the oxide surfaces for these two adsorbates involves adsorbate deprotonation with the formation, at the oxide surface, of molecular water which is subsequently desorbed and pumped away during sample junction preparation. For the 1,3- and 1,4-dihydroxy systems, on both oxides, the presence of a strong ν(OH) band at ≈3650 cm⁻¹ suggests that only one of the hydroxyl groups present in both systems is involved in adsorbate deprotonation interactions at the respective oxide surfaces, with the second hydroxyl group present contributing to the enhanced substrate oxide ν(OH) envelope observed.     

Which is reactive in alkaline solution, boronate ion or boronic acid? Kinetic evidence for reactive trigonal boronic acid in an alkaline solution

That boronic acid is a reactive species toward a diol moiety even in an alkaline solution and that the boronate ion is not very reactive were demonstrated by the estimated upper limit of the rate constants for the reactions of some boronic acids with 2,2'-biphenol and 2,3-dihydroxynaphthalene in a neutral-alkaline solution, which will correct a common misunderstanding in boron chemistry and would renew the idea of effective boronic acid sensor design for carbohydrates.     

Energetic heterocyclic N-oxides: synthesis and performance

Novel synthetic strategies toward construction and functionalization of nitrogen-rich energetic compounds bearing at least one heterocyclic N-oxide scaffold are briefly overviewed. The present focus review summarizes main recent advances (published in the period 2017–2022) in the chemistry of five- and six-membered heterocyclic N-oxides as well as their linear combinations and fused bi-, tri- and tetraheterocyclic frameworks which are of paramount importance for the development of next-generation energetic materials. Physicochemical properties along with detonation performance and mechanical sensitivities of the reported high-energy substances are discussed and their application potential is especially emphasized.     

Chemical Reactivity of Alkylidene Phosphoranes and the Relevant Phosphonium Salts Toward Some Carbon-Nitrogen Systems

The published work on the main chemical reactions of alkylidene phosphoranes and the relevant phosphonium salts with different carbon-nitrogen systems are thoroughly discussed, whereas their importance as synthones in heterocyclic chemistry are indicated briefly, and the long controversy concerning their structure is only summarized in order to expose the latest results on the subject. The literature has been fully covered up the last two decades.     

Reactivity of dehydroacetic acid in organic synthesis

This review reports the reactivity of dehydroacetic acid, which considered to be a very reactive organic compound. The structure of the title compound was investigated. The condensation reactions with primary amines led to the preparation of a variety of heterocyclic ring systems, including bispyran, pyrazole, thiazole, pyridine, pyrimidine, thiazine, thiazepine, and diazepine ring systems. On the other hand, the condensation reaction with aldehydes led to the formation of 1,5-benzodiazepines, pyran, and pyranopyran heterocyclic ring systems. The reaction mechanisms were discussed. The bibliography includes 130 references.     

Quinoxaline-2,3(1H,4H)-dithione: Synthesis and reactions

Quinoxaline-2,3(1H,4H)-dithione can be synthesized efficiently through the thionation of quinoxaline-2,3(1H,4H)-dione with phosphorous pentasulfide. It can also be obtained by reaction of 2,3-dichloroquinoxaline with thiourea or sodium hydrogen sulfide. The most common reactions of quinoxaline-2,3(1H,4H)-dithione involve deprotonation and electrophilic attack at the sulfur atoms to give various substituted derivatives and poly-fused heterocyclic ring systems. The current review aims to provide a survey of the developments in quinoxaline-2,3(1H,4H)-dithione chemistry until 2016.     

A simple and efficient approach to the synthesis of highly functionalized fused benzochromenes

Protonation of the reactive intermediates produced in the reaction between tert-butyl isocyanide and dimethyl acetylenedicarboxylate or dibenzoylacetylene, by 1-naphthol, 2-naphthol, 2,3-dihydroxynaphthalene, 2,7-dihydroxynaphthalene or 4-methyl-8-hydroxycoumarin leads to vinylnitrilium cations, which undergo carbon-centered Michael type addition with the conjugate base of the naphthols to produce highly functionalized benzochromenes.     

Synthesis of novel 2,2-disubstituted naphthodioxoles via an unprecedented reaction

A reaction of 2,3-dihydroxynaphthalene with ethyl-2,3-dibromo-3-phenyl-propionate or 1,3-diaryl-2,3-dibromo ketone under basic conditions led to the formation of novel 2,2-disubstituted naphthodioxoles.     

Generation and trapping of 2,3-naphthoquinone

2,3-Naphthoquinone generated from 2,3-dihydroxynaphthalene was trapped with cyclopentadiene and its properties examined by dc polarography and cyclic voltametry.     

Heterocyclic cation radicals (review)

The modern state of the chemistry of heterocyclic cation radicals is examined, Methods for the preparation (generation) of these particles, as well as their stabilities and the factors that determine them, are described, The mechanisms of the reactions of heterocyclic cation radicals with nucleophiles and specific examples of such reactions are discussed. Special attention is directed to the role of cation radicals as intermediate particles in dehydrogenation, nitration, and radical substitution reactions and in processes involving the cleavage of C-C bonds and dehydrodimerization in the heterocyclic series. The cation radicals of some natural heterocyclic compounds and their possible role in the functioning of biochemical systems are also examined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1011–1029, August, 1980     

1,3-dipolar cycloaddition of nitrones to free and coordinated nitriles: Routes to control the synthesis of 2,3-dihydro-1,2,4-oxadiazoles

Data on 1,3-dipolar cycloaddition of nitrones to free and coordinated nitriles producing 2,3-dihydro-1,2,4-oxadiazoles (or Δ⁴-1,2,4-oxadiazolines) are summarized. The latter compounds belong to the virtually unknown class of heterocyclic systems. The main factors responsible for the cycloaddition reactions are discussed. Particular attention is given to the role of metal centers in controlling the synthesis of 2,3-dihydro-1,2,4-oxadiazoles. Dedicated to Academician O. M. Nefedov on the occasion of his 75th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1803–1815, November, 2006.     

The Huisgen Reaction: Milestones of the 1,3‐Dipolar Cycloaddition

The concept of 1,3‐dipolar cycloadditions was presented by Rolf Huisgen 60 years ago. Previously unknown reactive intermediates, for example azomethine ylides, were introduced to organic chemistry and the (3+2) cycloadditions of 1,3‐dipoles to multiple‐bond systems (Huisgen reaction) developed into one of the most versatile synthetic methods in heterocyclic chemistry. In this Review, we present the history of this research area, highlight important older reports, and describe the evolution and further development of the concept. The most important mechanistic and synthetic results are discussed. Quantum‐mechanical calculations support the concerted mechanism always favored by R. Huisgen; however, in extreme cases intermediates may be involved. The impact of 1,3‐dipolar cycloadditions on the click chemistry concept of K. B. Sharpless will also be discussed.     

Chemistry of an Unexplored Heterocyclic Ring System: Versatile Synthesis of 5‐Aryl‐2,3,4‐benzothiadiazepine 2,2‐dioxides

The article gives insight into the synthetic approach of a practically new heterocyclic ring system, 2,3,4‐benzothiadiazepines. Starting from the easily available phthalides, an efficient synthesis of 5‐aryl‐2,3,4‐benzothiadiazepine 2,2‐dioxides is described here. Owing to their close structural similarity to 2,3‐benzodiazepines and 2,3‐benzodiazepine‐4‐ones, two well‐known bioactive compound families, the new derivatives can be of importance in medicinal chemistry.     

Phase transfer catalysis in the chemistry of heterocyclic compounds. A review

This review covers new data on the use of phase transfer catalysis in the chemistry of heterocyclic compounds. The following reactions are considered: alkylation, acylation, reactions with dihalocarbenes, preparations of ethers and esters, the formation of halo derivatives, oxidation and reduction, and isotope exchange. The advantages of phase transfer catalysis are examined and the prospects for its further development in heterocyclic chemistry are discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1443–1459, November, 1983.     

新型β-二酚卟啉光敏剂合成及其与DNA作用

以β-硝基卟啉为原料,分别与2,3-萘二酚或邻苯二酚直接反应,制备了6个新型β-二酚取代卟啉光敏药物,通过UV,~1H NMR,IR,MS,元素分析等手段对化合物进行了结构表征并初步探讨了反应机理.DNA凝胶电泳实验表明,该类光敏剂对pBR322质粒DNA具有很好的光敏切割作用,作为光敏剂或其前体具有很好的应用前景.