Reaction Of Thiocyanate Research Articles

Design, structure and antivirus molecular docking of chloridobis(1,10-phenanthroline)-(thiocyanato)-copper(II)

The reaction of sodium thiocyanate with CuCl2·2H2O salt using 1,10-phenanthtroline as a co-ligand led to chloridobis(1,10-phenanthroline)-(thiocyanato) copper(II), [Cu(Phen)2(Cl)(NCS)] (1). The structure of 1 was characterized by single crystal X-ray crystallography, UV-Visible and fluorescence spectroscopy. 1 crystallized in the monoclinic crystal system with space group P21/n and revealed a distorted octahedral coordination geometry. Electronic properties such as HOMO and LUMO energies were derived through DFT calculations. Hirshfeld surface analysis and 2D fingerprint plot was used to analyze the intermolecular interactions within the crystal structure. To develop anti-SARS-CoV-2 and anti-HIV drugs, we performed molecular docking studies for antiviral activity against the main protease (Mpro) of the SARS-CoV-2 (PDB ID: 6LU7 and 7LKD) and HIV-1 protease (PDB ID: 8FUI) viruses. The molecular docking calculations reveal that 1 with the Mpro of SARS-CoV-2 virus and HIV-1 protease virus resulted in calculated binding energies (ΔG) of −7.6, −7.5 and −7.2 kcal/mol with inhibition constant/dissociation constant (Ki/Kd ) values of 4.567, 4.432 and 4.632 µM, respectively. The in-vitro antibacterial study was conducted to check the efficacy of 1 against some selected bacteria. Further, the in-silico antiviral efficacy analysis shows the potential of this complex as an antiviral drug. 1 may be used as anti-SARS-CoV-2 and anti-HIV-1 agents.

Synthesis, structural characterization, Hirshfeld surface analysis and thermal properties of dibutyltin(IV)-based complexes containing thiocyanate and pyridyl ligands

Dibutyltin(IV) complex [SnBu2(NCS)2] (1) has been prepared from the reaction of SnBu2Cl2 and potassium thiocyanate in a molar ratio of Sn:KNCS/1:2 in ethanol. The reaction of [SnBu2(NCS)2] (1) with 4,4ꞌ-di-tert-butyl-2,2ꞌ-bipyridine (bu2bpy) in a molar ratio of Sn:bu2bpy/1:1 resulted in the formation of [SnBu2(NCS)2(bu2bpy)] (2). The products were characterized using elemental analysis, IR, and multinuclear NMR (1H, 13C, 119Sn) spectroscopy. The X-ray crystal structure determination of the complex [SnBu2(NCS)2(bu2bpy)] (2) revealed that the geometry around the Sn(IV) atom is highly distorted octahedral with trans-[SnBu2] configuration. On the other hand, the new single crystals of bu2bpy (3) were characterized by X-ray crystallography from the crystallization of 2 in diethyl ether. The various types of weak interactions in their networks have been assessed using the 3D Hirshfeld surface analysis and 2D fingerprint maps for 2, and 3 which show the major contribution of intermolecular interactions is related to H…H interactions. The thermal properties analysis showed that the complex [SnBu2(NCS)2] (1) is stable up to 153 °C while the complex [SnBu2(NCS)2(bu2bpy)] (2) is stable up to 190 °C.

Novel Aryl Thioamides Derivatives as Insect Growth Regulators Analogues against Spodoptera littoralis (Lepidoptera: Noctuidae): Design, Synthesis, Insecticidal Activity and Biochemical Impacts.

A significant reason for developing innovative insecticidal active agents is the exponential rise in resistance to traditional chemical pesticides. Exploring new classes of insecticidal compounds with distinct mechanisms of action is one way to address this difficulty. So that, novel aryl thioamides derivatives 3-15 has been synthesized viaone-pot, three-component reaction of aroyl chloride, ammonium thiocyanate, and aromatic amines in dry acetone. The newly synthesized compounds' structures were validated by various spectroscopic methods, including elemental analysis, 1H-NMR, 13C NMR, and infrared spectroscopy. Under laboratory circumstances, the synthesized compounds showed good and broad-spectrum insecticidal activities toward S. littorali. When compared to other synthetic target compounds, 2,4-dichloro-N-[(3-fluorophenyl)carbamothioyl]benzamide 11, 2,4-dichloro-N-[(3-fluorophenyl)carbamothioyl]benzenecarbothioamide 13 showed good insecticidal activity, with 46.33 mg/L and LC50 values of 49.25 mg/L for 2nd instar larvae. Furthermore, the compound 3 was the least toxic in controlling the second and fourth instar larvae of S. littoralis on tomato leaves. Additionally, several histopathological and biochemical features of the some synthesized compounds under laboratory circumstances were also examined.

Organophotocatalytic Remote Thiocyanation Reaction via Ring-Opening Functionalization of Cycloalkanols.

The remote C(sp3)-SCN bond formation via ring-opening functionalization of cycloalkanols with N-thiocyanatosaccharin as the precursor of SCN radicals and pyrylium salt as the organic photocatalyst under visible light has been developed. Thus, various terminal keto thiocyanates were prepared without transition metals and oxidants in moderate to good yields. The simplicity, wide substrate scope and mild conditions feature its synthetic application capability.

Understanding into interfacial properties and reactivity of COFs toward accelerating Menshutkin SN2 reaction

Given the poor understanding about the effects of confined polar microenvironment on interfacial behaviors of Menshutkin SN2 reaction, herein, the interfacial properties and reactivities between 1-methylimidazole and methyl thiocyanate reaction induced by interfacial polar microenvironments of covalent organic frameworks (COFs) with varying pore size and functional groups were investigated using in situ Fourier transform infrared spectroscopy, molecular dynamics simulations, and metadynamics calculations. The decreased nanopore size of COFs from 3.2 to 1.2 nm can enlarge reaction rates (k) and reduce activation energy barriers (ΔE*). The hydroxyl-modified COF (2.8 nm) can further cause larger k and lower ΔE* by 6.1 and 0.8 kJ/mol compared to the bulk and smaller pore-size COF (1.2 nm) system, respectively, mainly originating from induced higher aggregation, preferred orientation, and the stabilization of charge separation of transition state. This work provides a systematic understanding for the confined interfacial properties toward accelerating the Menshutkin reaction.

NBS-Promoted Synthesis of Thiocyanated Aminomaleimides and Site-Selective Intramolecular Cyclization Access to 1,4-Benzothiazepines via S-CN Bond Cleavage.

A transition metal-free concise and efficient protocol for the synthesis of thiocyanated aminomaleimides and benzo[e][1,4]thiazepine derivatives has been developed. The method involves an initial α-C-H thiocyanation of aminomaleimides with KSCN and TEMPO-mediated tandem S-CN bond cleavage/intramolecular cyclization substitution processes, which enables the formation of seven-membered S/N-heterocycles. This synthetic strategy provides a reliable method for the synthesis of biologically interesting benzo[e][1,4]thiazepine derivatives by using KSCN as sulfur sources as well as expands the application of enaminones thiocyanation reactions in heterocycles synthesis.

One‐pot Microwave‐assisted Synthesis of Pyrazolopyrimidines from 5‐Amino‐4‐thiocyanato‐pyrazoles with Vilsmeier Reagent

AbstractA facile one‐pot microwave‐assisted synthesis of pyrazolopyrimidines and pyrazolothiazoles was developed by reacting 5‐amino‐4‐thiocyanato‐pyrazoles with Vilsmeier Reagent (PBr3/foramide). The reaction gave the corresponding pyrazolopyrimidines as major products in good yields (61–85 %) and pyrazolothiazoles as minor products (11–23 % yields). The plausible reaction mechanism was proposed to account for the transformation of pyrazolopyrimidines and pyrazolothiazoles through two paths A and B. In path A, the reaction leading to the formation of pyrazolopyrimidines proceeded through four sequential steps, including acidic catalyzed cascade dethiocyanation/cyclization, Vilsmeier reaction, ring expansion, and deamination. The formation of the pyrazolothiazole in path B was caused by the nucleophilic heterocyclization reaction involving the sulfur nucleophilic reaction of thiocyanate (R−SC≡N) and the departure of a cyanamide. Based on the experimental results, we observed that the path A for the formation of pyrazolopyrimidines was more favorable.

Lewis Base Catalyzed C−S Bond Formation Through Methyl C(sp3)‐H Thiocyanation of Indoles

AbstractA Lewis base catalyzed C−S bond formation through thiocyanation of methyl C(sp3)−H bond is reported. The method involves a sequential chlorination and thiocyanation reaction. This simple yet effective protocol works with diverse array of indoles to furnish thiocyanated products in good yield (up to 85 %). The developed method is also applied for the synthesis of phercaptoline (hypotensive agent) and umifenovir (antiviral drug).

Recent Advancement on the Indirect or Combined Alternative Thiocyanate Sources for the Construction of S-CN Bonds.

The process of thiocyanation is a notable chemical conversion owing to the extensive range of applications associated with thiocyanate compounds in the field of organic chemistry. In past centuries, the thiocyanation reaction incorporated metal thiocyanates or thiocyanate salts as sources of thiocyanate, which are environmentally detrimental and undesirable. In recent literature, there have been numerous instances where combined or indirect alternative sources of thiocyanate have been employed as agents for thiocyanation, showcasing their noteworthy applications. The present literature review focuses on elucidating the ramifications associated with the utilization of indirect or combined alternative sources of thiocyanate in various thiocyanation reactions.

Development of facile field-test paper for rapid determination of iron contamination in natural water of acid sulfate soils

Abstract The iron concentration in natural water of acid sulfate soils is usually determined by complicated methods of SMEWW 3111B:2017 or ISO 6332: 1988 E in the laboratory for acidified water samples at pH ∼2–3. Therefore, the rapid field determination of iron content in natural water is a very useful method because it limits the error and reduces the experimental time for analysis. In this study, we proposed, developed, and tested a rapid colorimetric analysis method based on the chemical reaction of ferric and anion thiocyanate (SCN−) ions for an iron concentration range of 0–100 mg/L with a linear equation of ΔE = 0.5955x + 2.0909 and high correlation coefficient (R2) of 0.9864. The results from 10 water samples by this method were very close to those by flame absorption spectroscopy with a difference of less than 5%. Besides the biggest advantage of rapid site testing, this method also gives quite high accuracy compared to the molecular absorption method of ISO 6332:1988 E. In addition, this new method can quantify Fe3+, Fe2+, and total iron in water, suggesting a very useful and potential method for determining the iron content of natural water from acid sulfate soils.

Synthesis, crystal structure and properties of tetra-kis-(pyridine-3-carbo-nitrile)-dithio-cyanatoiron(II) and of diaqua-bis-(pyridine-3-carbo-nitrile)-di-thio-cyanatoiron(II) pyridine-3-carbo-nitrile monosolvate.

The reaction of iron thio-cyanate with 3-cyano-pyridine (C6H4N2) leads to the formation of two compounds with the composition [Fe(NCS)2(C6H4N2)4] (1) and [Fe(NCS)2(C6H4N2)2(H2O)2]·2C6H4N2 (2). The asymmetric unit of 1 consists of one iron cation, two thio-cyanate anions and four 3-cyano-pyridine ligands in general positions. The iron cation is octa-hedrally coordinated by two N-bonded thio-cyanate anions and four 3-cyano-pyridine ligands. The complexes are arranged in columns along the crystallographic c-axis direction and are linked by weak C-H⋯N inter-actions. In 2, the asymmetric unit consists of one iron cation on a center of inversion as well as one thio-cyanate anion, one 3-cyano-pyridine ligand, one water ligand and one 3-cyano-pyridine solvate mol-ecule in general positions. The iron cation is octa-hedrally coordinated by two N-bonded thio-cyanate anions, two cyano-pyridine ligands and two water ligands. O-H⋯N and C-H⋯S hydrogen bonding is observed between the water ligands and the solvent 3-cyano-pyridine mol-ecules. In the crystal structure, alternating layers of the iron complexes and the solvated 3-cyano-pyridine mol-ecules are observed. Powder X-ray (PXRD) investigations reveal that both compounds were obtained as pure phases and from IR spectroscopic measurements conclusions on the coordination mode of the thio-canate anions and the cyano-group were made. Thermogravimetric (TG) and differential thermoanalysis (DTA) of 1 indicate the formation of a compound with the composition {[Fe(NCS)2]3(C6H4N2)4}n that is isotypic to the corresponding Cd compound already reported in the literature. TG/DTA of 2 show several mass losses. The first mass loss corresponds to the removal of the two water ligands leading to the formation of 1, which transforms into {[Fe(NCS)2]3(C6H4N2)4}n, upon further heating.

The "weak" C-H···S interaction drives enantioselectivity in cinchona alkaloid complex catalyzed thiocyanation.

The great success of asymmetric organocatalysis has made it one of the most important advancements made in chemistry in the past two decades. A significant achievement in this context is the asymmetric organocatalysis of the thiocyanation reaction. In the current study, computational studies with density functional theory have been done in order to understand an interesting experimental finding: the reversal of enantioselectivity from R to S when the electrophile is changed from b-keto ester to oxindole for the thiocyanation reaction with the cinchona alkaloid complex catalyst. The calculations reveal an unusual fact - the principal reason for the reversal is the presence of the C-H···S noncovalent interaction, which is present only in the major transition states in each of the two nucleophile cases. Only recently has it been realized that the supposedly weak C-H···S noncovalent interaction has the properties of a hydrogen bond, and the fact that this interaction is the cause of enantioselectivity has relevance, because of the large number of asymmetric transformations involving the sulphur heteroatom.

One‐Pot Synthesis of 4‐Thiocyanato‐1H‐pyrazoles through Electrochemical Multicomponent Thiocyanation under Metal‐ and Oxidant‐Free Conditions

AbstractAn electrochemical oxidative three‐component tandem reaction of arylhydrazines, 1,3‐diketones and ammonium thiocyanate has been established to construct 4‐thiocyanato‐1H‐pyrazoles under metal‐, oxidant‐free and mild conditions in an undivided cell. Various 4‐thiocyanato‐1H‐pyrazole derivatives could be obtained with broad substrate scope, and excellent functional group tolerance from available raw materials in moderate to excellent yields. This thiocyanation protocol with practicability and scalability features economical and eco‐friendly.

A efficient, metal-free and sustainable synthesis, C-S linked by simple C-H thiocyanation of 4-aminocoumarin or 4-(N-aryl)aminocoumarin derivativess

In the present study, we describe the successful development of a novel and efficient C(sp2)−H thiocyanation reaction of 4-aminocoumarin and 4-(N-aryl)aminocoumarin derivatives with readily available using KSCN as thiocyanating agent and K2S2O8 as an oxidant in ACN under the air atmosphere and room temperature. The most notable point, the reaction proceeded smoothly without the addition of any metal catalyst or strong oxidant and heat, ultimately minimizing the production of chemical waste. The advantages of this reaction met the requirements of green and sustainable synthetic chemistry and may be widely used in organic synthesis and pharmaceutical chemistry.

Photo- and Electrochemically Initiated Thiocyanation Reactions

Photo- and Electrochemically Initiated Thiocyanation Reactions

Ambiphilic Behavior of Ge(II)-Pseudohalides in Inter- and Intramolecular Frustrated Lewis Pair Alkyne Addition Reactions.

The reaction of the germylene chloride (NacNac)GeCl (1, NacNac = CH{(CMe)(2,6-iPr2C6H3N)}2), phenylacetylene, and B(C6F5)3 gives the intermolecular frustrated Lewis pair (FLP) addition product 2. In this case, the Ge(II) center acts as a base. In contrast, the analogous reaction of germylene thiocyanate 3 reacts independently with B(C6F5)3 to give the germylene cation salt [(NacNac)Ge][SCNB(C6F5)3] 4. Subsequent in the presence of alkynes, the Ge(II) cation and γ-C of 4 act as a Lewis acidic and basic center, respectively, to affect the addition of alkynes, affording products [(NacNac)Ge(RCCR')][SCNB(C6F5)3] 5 and 6. Compound 4 also reacts with Me3SiCN to give the cyanide-bridged Ge/B species 7, which also reacts with phenylacetylene to give CN abstraction and intramolecular addition yielding the salt [(NacNac)Ge(PhCCH)][NCB(C6F5)3] 8. Despite the similarity of 1 and 3, DFT calculations show that the highest occupied molecular orbital (HOMO) of 1 is mainly located at the more sterically hindered germylene center, while the HOMO of 3 is located on the less sterically hindered NCS group, prompting markedly different FLP addition products.

Synthesis, characterization, and some pharmacological evaluation of 5-Thiocyanatouracil compound

5-Thiocyanotouracil (5-TCU) was prepared in convenient method involved direct reaction of Potassium thiocyanate with 5-Iodouracil in refluxing aqueous solvent to give white crystalline in very good yield and high purity. This compound is important because it is similar in structure to 5-Flourouracil, which is of great importance as anti-cancer drug that is still used today. FT-IR, 1H- NMR, 13C- NMR, and CHN elemental analyses were used to describe the product. Median lethal dose LD50, in vitro antiradical activity and antibacterial effects were done. The results indicated that 5-TCU has relatively high LD50, non-significate antioxidant effect compare with ascorbic acid, and some antibacterial activity.

Photocatalytic C-H Thiocyanation of NH2-Enaminones and the Tunable Synthetic Routes to 2-Aminothiazoles and 2-Thiazolinones.

Visible light photocatalytic reactions of NH2-enaminones and ammonium thiocyanate for chemoselective α-C-H thiocyanation have been realized for the first time, providing a sustainable route for the synthesis of thiocyanated NH2-enaminones. In addition, the thiocyanated enaminone products can be flexibly transformed into 2-aminothiazoles and 2-thiazolinones via a simple operation.

Eelectrosynthesis of benzothiazole derivatives via C–H thiolation

Abstract Benzothiazole derivatives are essential intermediates in synthesizing a wide variety of medical and pharmaceutical compounds, and there is a great demand for a simple and efficient method to synthesize benzothiazoles under mild reaction conditions. Organic electrosynthesis as an energy-efficient process represents an environmentally benign and safer method than traditional methods for organic synthesis. Herein, we present bromine-free and straightforward synthesis of 2-amino benzothiazole derivatives via the reaction of aniline derivatives and ammonium thiocyanate using electrosynthesis in the presence of sodium bromide both as an electrolyte and as a brominating agent at room temperature in isopropyl alcohol (i-PrOH) as a solvent. The reaction of ammonium thiocyanate via C–H thiolation routes, using various aniline derivatives, resulted in a simple, green, and bromine-free synthesis of 2-amino benzothiazole in moderate to good yields under mild reaction conditions. Riluzole drug can be produced using the same procedure in moderate yields.

An efficient synthesis of 4-Thiocyanato anilines using benzyltrimethylammonium dichloroiodate and ammonium thiocyanate in DMSO:H2O

Treatment of a variety of 2(3)- mono-substituted anilines with benzyltrimethylammonium dichloroiodate (1.2 equiv) and ammonium thiocyanate (1.2 equiv) in DMSO:H2O (9:1) at 70 °C gave the corresponding 4-thiocyanato-2(3)-substituted anilines in excellent isolated yields (60–99%; ave. yield for all anilines = 90%). The reaction worked well for substrates with 2-halo, 2-alkoxy, 2-aryloxy, 2-alkyl, 2-dialkylamino, 2-N-sulfonylamino, 2-alkyn-1-yl, 2-cyano, 2-acyl, 2-sulfonyl, and 2-heteroaryl substitution. 3-Substituted, 3,5- or 2,6-disubstituted anilines and substituted phenols were also well tolerated. 4-Substituted anilines gave the corresponding 2-aminobenzothiazole products, whereas 4-, 5-, 6-, or 7-substituted indoles were not reactive. Regioselective thiocyanation of 2-quinoline, 3-amino-1-methylpyrazole, 2-amino-4-phenylthiazole, and 2-phenylimidazo[1,2-a] pyridine was achieved in 93–99% yield, thus demonstrating the broad-substrate scope for this thiocyanation reaction.