Iodine Reagents Research Articles

Merging the Reactivity of (Pseudo)cyclic Hypervalent Iodine Reagents and Carbenes or Carbenoids

AbstractIn this short review, we present applications merging the reactivity of cyclic hypervalent iodine reagents with carbenes and carbenoids developed in the period 2014–2024. The use of more stable cyclic hypervalent iodine reagents has led to major advances in this area. The combination of iodine(III) chemistry with carbenes or carbenoids enables new disconnections that are not possible using classical reactivity. Both the use of hypervalent iodine compounds as partners in reactions with metal carbenes and as reagents combining the reactivity of iodine(III) and carbenes in a single molecule to give carbyne equivalents are discussed in this review.1 Introduction2 Transfer of Fluorinated Groups (F, CF3)3 Oxy- and Aminoalkyn(en)ylation3.1 Oxy- and Aminoalkynylation with Acceptor-Substituted Diazo Compounds3.2 Oxyalkenylation with Acceptor-Substituted Diazo Compounds3.3 Oxyalkynylation with Acceptor-Acceptor-Substituted Diazo Compounds4 Carbyne Equivalents4.1 Diazo-Based Reagents4.2 Sulfur Ylide Based Reagents5 Conclusion

Improvement of thermostable productivity ?-amylase from local isolate Bacillus licheniformis H14.

(28)Bacterial local isolates of Bacillus sp. were obtained from soil samples. Isolates were tested for thermostable alpha- amylase production on solid media; fifteen isolates were able to develop clear zone around the bacterial growth after floating the plates with iodine reagent (Lugol's solution). There were further tested in submerged culture which led to selection of Bacillus sp. H14since it was the most efficient .Microbial and biochemical tests showed that the local isolate Bacillus sp.H14was refered to the species B.licheniformis that signed as H14 was refered to the species B.licheniformis H14 .,To get ahigher yield of alpha – amylase(48.70unit/mg protein) production from the local isolate B.licheniformis H14 . This study used different mutation ways such as physical way by using the physical mutagen (ultraviolet light) and chemical way by using the chemical mutagen (nitrosoguanidine). Physical mutation results showed that the local isolate B.licheniformis HM14 get higher yield of alpha – amylase production(102.10 unit/mg protein) according to killing percentage (90%) while the chemical mutation results showed that the local isolate B.licheniformis HM4 get higher yield of alpha –amylase production(100.94 unit/mg protein) from the two mutant local isolates (HM14 and HM4)were the best carbon source starch (1.5%), peptone (1.5%) as nitrogen source, calcium chloride (0.02%), sodium chloride (0.05%), magnicium phosphate (0.05%), sodium di –hydrogen phosphate (0.16%), at initial pH (5) and inoculum size 1*108 cfu/ml at (50?C) For (72) hours, using shaking incubator at (150) rpm.

Synthesis, Material Properties, and Organocatalytic Performance of Hypervalent Iodine(III)-Oxidants in Core–Shell-Structured Magnetic Nanoparticles

Magnetic nanoparticles (MNPs) based on magnetite (Fe3O4) are attractive catalyst supports due to their high surface area, easy preparation, and facile separation, but they lack stability in acidic reaction media. The search for MNPs stable in oxidative acidic reaction media is a necessity if one wants to combine the advantages of MNPs as catalyst supports with those of iodine(III) reagents being environmentally benign oxidizers. In this work, immobilized iodophenyl organocatalysts on magnetite support (IMNPs) were obtained by crossed-linking polymerization of 4-iodostyrene with 1,4-divinylbenzene in the presence of MNPs. The obtained IMNPs were characterized by TGA, IR, SEM, STEM, and HAADF to gain information on catalyst morphology, average particle size (80–100 nm), and their core–shell structure. IMNP-catalysts tested in (i) the α-tosyloxylation of propiophenone 1 with meta-chloroperbenzoic acid (m-CPBA) and (ii) in the oxidation of 9,10-dimethoxyanthracene 3 with Oxone® as the side-oxidant showed a similar performance as reactions using stoichiometric amounts of iodophenyl. The developed IMNPs withstand strong acidic conditions and serve as reusable organocatalysts. They are recyclable up to four times for repeated organocatalytic oxidations with rates of recovery of 80–92%. This is the first example of a—(4-iodophenyl)polystyrene shell—magnetite core-structured organocatalyst withstanding strong acidic reaction conditions.

Skeletal Editing by Hypervalent Iodine Mediated Nitrogen Insertion.

Hypervalent iodine reagents are versatile and readily accessible reagents that have been extensively applied in contemporary synthesis in modern organic chemistry. Among them, iodonitrene (ArI=NR), is a powerful reactive species, widely used for a single-nitrogen-atom insertion reaction, and skeletal editing to construct N-heterocycles. Skeletal editing with reactive iodonitrene components has recently emerged as an exciting approach in modern chemical transformation. These reagents have been extensively used to produce biologically relevant heterocycles and functionalized molecular architectures. Recently, the insertion of a nitrogen-atom into hydrocarbons to generate N-heterocyclic compounds using hypervalent iodine reagents has been a significant focus in the field of molecular editing reactions. In this review, we discuss the rapidly emerging field of nitrene insertion, including skeletal editing and nitrogen insertion, using hypervalent iodine reagents to access nitrogen-containing heterocycles, and the current mechanistic understanding of these processes.

Recent Progress in Synthetic Applications of Hypervalent Iodine(III) Reagents.

Hypervalent iodine(III) compounds have found wide application in modern organic chemistry as environmentally friendly reagents and catalysts. Hypervalent iodine reagents are commonly used in synthetically important halogenations, oxidations, aminations, heterocyclizations, and various oxidative functionalizations of organic substrates. Iodonium salts are important arylating reagents, while iodonium ylides and imides are excellent carbene and nitrene precursors. Various derivatives of benziodoxoles, such as azidobenziodoxoles, trifluoromethylbenziodoxoles, alkynylbenziodoxoles, and alkenylbenziodoxoles have found wide application as group transfer reagents in the presence of transition metal catalysts, under metal-free conditions, or using photocatalysts under photoirradiation conditions. Development of hypervalent iodine catalytic systems and discovery of highly enantioselective reactions using chiral hypervalent iodine compounds represent a particularly important recent achievement in the field of hypervalent iodine chemistry. Chemical transformations promoted by hypervalent iodine in many cases are unique and cannot be performed by using any other common, non-iodine-based reagent. This review covers literature published mainly in the last 7-8 years, between 2016 and 2024.

Elektrochemische Gerüst‐Editierung von Indolen durch Stickstoffatom‐Insertion mit nachhaltiger Sauerstoff‐Reduktionsreaktion

AbstractMolekulares Editieren hat in letzter Zeit stark an Bedeutung gewonnen und sich als einzigartiges Werkzeug für Late‐Stage Diversifizierungen erwiesen. Bislang waren für die Indol‐Editierung meist überstöchiometrische Mengen an teuren hochvalenten Iod(III)‐Reagenzien erforderlich. Im Gegensatz dazu zeigen wir hier, dass Elektrizität nachhaltige Stickstoffatom‐Insertionsreaktionen ermöglicht, um bio‐relevante Chinazolin‐Gerüste ohne stöchiometrische chemische Redox‐Abfallprodukte zu erhalten. Die Übergangsmetall freie Elektro‐Editierung wurde durch die Sauerstoff‐Reduktionsreaktion (ORR) ermöglicht und erwies sich in großem Maßstab als robust, wobei eine Vielzahl wertvoller funktioneller Gruppen toleriert wurden.

Synthesis of pyrazole and pyrazoline derivatives of β-ionone: Exploring anti-inflammatory potential, cytotoxicity, and molecular docking insights

In the present paper, pyrazole and pyrazoline derivatives of β-ionone were synthesized. The protocol involved intramolecular oxidative C–H amination of hydrazone to yield corresponding pyrazole in moderate to good yields. Another methodology comprising of condensation of hydrazine hydrochloride with β-ionone in methanol leading to pyrazoline and its oxidative dehydrogenation using hypervalent iodine reagent to synthesize pyrazole is also achieved. One pot methodology for synthesis of pyrazole is also developed by refluxing the hydrazine hydrochloride with β-ionone in acetic acid. The structures of the synthesized compounds were elucidated using 1H NMR, 13C NMR, FTIR and mass spectrometry. All the pyrazole and pyrazoline derivatives were subjected to bovine serum albumin assay for in-vitro anti-inflammatory activity and all the compounds exhibited good to excellent activity. Compounds containing bromo and sulfonamide group exhibited inhibition rates of 87.36 % and 85.82 %, respectively, at a concentration of 0.5 mg/mL, surpassing the efficacy of the standard drug celecoxib (81.67 %). Further, cytotoxicity of the compounds was also evaluated against VERO cell line and all the compounds exhibited the cytotoxic values almost similar to the standard. Molecular docking was performed to study binding affinity of the potent compounds i. e bromo bearing pyrazole and sulfonamide bearing pyrazoline into the crystal structure of COX-II enzyme (PDB ID: 3LN1) at celecoxib binding site to determine the binding energy and interactions.

Hypervalent Iodine Mediated Ring-Opening 1,3-Difluorination of Benzylidenecyclopropanes

Abstract1,3-Difluorinated compounds are characterized by their unique conformation, influenced by 1,3-dipolar minimization effects. However, their synthetic methods are relatively limited. Here, a ring-opening 1,3-difluorination of benzylidenecyclopropanes (BCPs) using HF·Py, mediated by an electron-poor hypervalent iodine reagent, which is generated in situ by the oxidation of o-nitroiodobenzene with mCPBA is described. The protocol features mild reaction conditions, good functional group tolerance, and moderate to good yields. Additionally, the synthetic utility of this method is showcased by further transformations of the olefin group and allylic fluoride motif.

Photocatalytic Oxyalkynylation of Unactivated Alkenes Enabled by Hypervalent Iodine(III) Reagents

Photocatalytic Oxyalkynylation of Unactivated Alkenes Enabled by Hypervalent Iodine(III) Reagents

Mn(II)-Catalyzed Markovnikov Hydroiodination of Terminal Aryl Alkynes.

A Mn(II)-catalyzed Markovnikov hydroiodination of terminal aryl alkynes with TMSI as the iodination reagent has been developed. Cheap Mn(OAc)2·4H2O was employed as the catalyst. Twenty-five aryl alkynes (including two internal alkynes) were successfully transformed into their α-iodide styrene derivatives, including those natural product-based alkynes and poly alkynyl benzenes. The reaction has good chemoselectivity of alkynes over alkenes, which enabled the tolerance of olefin in the substrate. Gram-scale synthesis was also conducted.

Transition-Metal-Free Sulfoximidation of Sulfonylhydrazones for the Synthesis of N-Sulfanylidenehydrazonamides.

Herein, we report a transition-metal-free C-H bond sulfoximidation protocol of sulfonyl hydrazones with hypervalent iodine(III) reagents. A library of novel N-sulfaneylidenehydrazonamides was constructed via chemoselective C-N bond formation reactions at aldehyde C-H bonds of sulfonyl hydrazones in the presence of a base. The reaction demonstrated broad substrate group diversity under exceedingly mild reaction conditions, and excellent yields were achieved at room temperature.

Structural Modification and Characteristics of Lappaconitine Alkaloid for the Discovery of Bioactive Components by Hypervalent Iodine Reagent.

Lappaconitine, a diterpene alkaloid isolated from Aconitum sinomontanum Nakai, exhibits a wide range of biological activities, making it a promising candidate for the development of novel derivatives with therapeutic potential. In our research, we executed a two-step transformation via oxidative cleavage of lappaconitine's vicinal diol using the hypervalent iodine reagent PhI(OAc)2, followed by strong alkaline hydrolysis. This approach yielded four new unanticipated compounds, whose structures were identified by spectroscopic methods and/or X-ray crystallography. Thus, we proposed plausible reaction mechanisms for their formations and particularly investigated the remarkable diastereoselectivity for the formation of single stereoisomer 8 observed during the alkaline hydrolysis step. Among them, compound 8 (code name: QG3030) demonstrated both enhanced osteogenic differentiation of human mesenchymal stem cells and significant osteogenic effect in an ovariectomized rat model with no acute oral toxicity.

2,2‐Difluoroethylation of Heteroatom Nucleophiles via a Hypervalent Iodine Strategy

AbstractThe 2,2‐difluoroethyl group is an important lipophilic hydrogen bond donor in medicinal chemistry, but its incorporation into small molecules is often challenging. Herein, we demonstrate electrophilic 2,2‐difluoroethylation of thiol, amine and alcohol nucleophiles with a hypervalent iodine reagent, (2,2‐difluoro‐ethyl)(aryl)iodonium triflate, via a proposed ligand coupling mechanism. This transformation offers a complementary strategy to existing 2,2‐difluoroethylation methods and allows access to a wide range of 2,2‐difluoroethylated nucleophiles, including the drugs Captopril, Normorphine and Mefloquine.

2,2-Difluoroethylation of Heteroatom Nucleophiles via a Hypervalent Iodine Strategy.

The 2,2-difluoroethyl group is an important lipophilic hydrogen bond donor in medicinal chemistry, but its incorporation into small molecules is often challenging. Herein, we demonstrate electrophilic 2,2-difluoroethylation of thiol, amine and alcohol nucleophiles with a hypervalent iodine reagent, (2,2-difluoro-ethyl)(aryl)iodonium triflate, via a proposed ligand coupling mechanism. This transformation offers a complementary strategy to existing 2,2-difluoroethylation methods and allows access to a wide range of 2,2-difluoroethylated nucleophiles, including the drugs Captopril, Normorphine and Mefloquine.

Iodine(III) reagents for the aromatic functionalization with inorganic groups

Iodine(III) reagents have gained importance in organic synthesis due to their strong oxidative properties in addition to several advantages over other related such as, non-toxic, green, easy to handle and in general safe for using. These characteristics become them useful tools and represent relevant alternatives to procedures which involves harsh and/or hazardous reaction conditions. They are versatile oxidants that has been largely used in the functionalization of a broad variety of aromatic nucleus, resulting in the introduction of several groups, including in the most general classification, organic and inorganics. In this sense, the metal-free arylation mediated by iodine(III) reagents is the most reported issue in the literature. Nevertheless, other relevant inorganic functionalities were also introduced. Herein, we review the most important procedures described to date for the aromatic functionalization with inorganic groups such as halogens, as well as the nitro-, azido, cyano-, sulfur- and selenium groups, under the iodine(III) chemistry.

Hypervalent Iodine Promoted Selective [2 + 2 + 1] Cycloaddition of Aromatic Ketones and Methylamines: A One-Pot Access to 1-Pyrrolines.

Herein, a versatile highly regioselective three-component annulation of simple aromatic ketones and methylamines using a hypervalent iodine reagent for polyarylated 1-pyrrolines has been described in good to excellent yields. Meanwhile, unsymmetrical 1-pyrroline isomers could be realized and synthesized. Such an intriguing one-pot two-step tandem assembly strategy with green conditions and high regioselectivity shows predictable inspiration in related annulation reactions.

Ruthenium and Iodine Anion Cocatalyzed Cascade Dihalogenation and Cyclization of Internal Alkyne-Tethered Cyclohexadienones with 1,2-Dihaloethanes.

We have established an efficient ruthenium(II) and iodine anion cocatalyzed dihalogenation and cascade cyclization of internal alkyne-tethered cyclohexadienones, which stereoselectively afforded numerous dihalogenation products with a bioactive hydrobenzofuran skeleton in high yields under mild conditions. In this transformation, the reaction pathway was determined by the concentration of electrophilic iodine reagent, which also provided a strategy for control of the reaction selectivity. Furthermore, this method features the use of 1,2-dihaloroethane as the halogen source via iodine anion catalyst.

Electrochemical Skeletal Indole Editing via Nitrogen Atom Insertion by Sustainable Oxygen Reduction Reaction.

Skeletal molecular editing gained considerable recent momentum and emerged as a uniquely powerful tool for late-stage diversifications. Thus far, superstoichiometric amounts of costly hypervalent iodine(III) reagents were largely required for skeletal indole editing. In contrast, we herein show that electricity enables sustainable nitrogen atom insertion reactions to give bio-relevant quinazoline scaffolds without stoichiometric chemical redox-waste product. The transition metal-free electro-editing was enabled by the oxygen reduction reaction (ORR) and proved robust on scale, while tolerating a variety of valuable functional groups.

Alkene Dialkylation with Alkyl Halides and Hypervalent Iodine Reagents by Dual Photoredox/Nickel Catalysis

Alkene Dialkylation with Alkyl Halides and Hypervalent Iodine Reagents by Dual Photoredox/Nickel Catalysis

Advancing carbohydrate functionality: The role of hypervalent iodine

Hypervalent iodine reagents have undergone significant development and widespread application in the functionalization of carbohydrates. This is primarily attributed to their exceptional properties, including mildness, ease of handling, high selectivity, environmental friendliness, and stability. This review aims to emphasize the utilization of hypervalent iodine compounds in the functionalization of carbohydrates. The present article covers various aspects, including glycal functionalization, C–H or N–H insertion reactions, O-arylations, C-2 deoxy-2-iodo glycoconjugates, iminosugars, and C3-oxo-glycals, achieved through the use of hypervalent iodine reagents/catalysts. Additionally, it explores hypervalent iodine-mediated bioactive 1,3,5-trioxocane synthesis followed by rare sugars synthesis.