Convenient Synthesis Research Articles

Organocatalyzed Controlled Radical Copolymerization toward Hybrid Functional Fluoropolymers Driven by Light

AbstractPhoto‐controlled polymerizations are attractive to tailor macromolecules of complex compositions with spatiotemporal regulation. In this work, with a convenient synthesis for trifluorovinyl boronic ester (TFVB), we report a light‐driven organocatalyzed copolymerization of vinyl monomers and TFVB for the first time, which enabled the controlled synthesis of a variety of hybrid fluorine/boron polymers with low dispersities and good chain‐end fidelity. The good behaviors of “ON/OFF” switch, chain‐extension polymerizations and post‐modifications further highlight the versatility and reliability of this copolymerization. Furthermore, we demonstrate that the combination of fluorine and boron could furnish copolymer electrolytes of high lithium‐ion transference number (up to 0.83), bringing new opportunities of engineering high‐performance materials for energy storage purposes.

A convenient synthesis, in silico study and crystal structure of novel sulfamidophosphonates: Interaction with SARS-CoV-2

A one-pot synthetic strategy was developed for the synthesis of novel sulfamidophosphonates via a three-component Kabachnik-Fields reaction of sulfanilamide, triethyl phosphite, and various aldehyde using ultrasound irradiation. Seven organophosphorus derivatives were synthesized with high yields through this newly developed method. The target compounds were characterized by 1H, 31P, 13C NMR, and IR. The molecular structure of 4a was obtained by X-ray diffraction on the monocrystal. Crystal belongs to the orthorhombic system with space groups Pbca. Insight into the binding mode of the synthesized compounds (ligand) into the binding sites of SARS-CoV2 (PDF code: 5R80) was provided by docking studies, performed with the help of Maestro 9.0 docking software.

One‐Pot Multicomponent Synthesis of Bis(diamino‐1,3,5‐triazines) under Microwave Irradiation

AbstractA new method for the synthesis of bis(1,3,5‐triazine‐2,4‐diamines) was developed using a one‐pot multicomponent approach. The synthesis was performed using the acid‐catalyzed reaction of cyanoguanidine with amines and aldehydes, followed by dehydrogenative aromatization of the dihydrotriazine intermediates upon heating with alkali. Two types of bis(1,3,5‐triazine‐2,4‐diamines) were prepared using either piperazine as the bifunctional amine or terephthaldehyde as the bifunctional aldehyde thus affording products with a piperazine or p‐phenylene link between two 1,3,5‐triazine rings. The microwave‐assisted method allows fast and convenient synthesis of diverse bis(1,3,5‐triazine‐2,4‐diamines).

Synthesis and biological evaluation of arene ruthenium(II) complexes containing thiophene benzhydrazone derivative ligands

A convenient synthesis of eight new ruthenium(II) thiophene benzhydrazone complexes (1–8) having the general formula [(η6-arene)Ru(L)Cl] (arene: benzene or p-cymene; L: bidentate substituted thiophenebenzhydrazone derivatives) has been described. They have been isolated as neutral mononuclear N∩O chelating ruthenium(II) complexes. When further reacted with sodium azide in methanol, these neutral ruthenium(II) thiophenebenzhydrazone complexes yielded corresponding azido ruthenium complexes (9–16). The complexes were characterized by IR, UV–Vis, NMR and ESI-MS spectral methods. The solid-state molecular structures of the representative complexes were determined using a single-crystal X-ray diffraction study and the geometry of complexes are pseudo octahedral and similar to the piano stool structures. The N∩O binding mode is through the azomethine nitrogen and the imidolate oxygen forming a five-membered chelating ring. All the complexes and the ligands were thoroughly screened out for antibacterial and antioxidant activity studies in which few of the complexes exhibited antibacterial activity against Gram-positive bacterial strains i.e., S. aureus and B. thuringiensis. Complex 7 shows the highest bacterial inhibition towards S. aureus, whereas complexes 7 and 8 show the highest inhibition towards B. thuringiensis. While for antioxidant activity study, it has been found that the antioxidant activity of the complexes is more prominent as compared to their respective ligands.

A Convenient Synthesis of Core‐shell ZSM‐5@MoO3 Catalyst for Enhanced Catalytic Properties in Methane Aromatization

AbstractA novel core‐shell ZSM‐5@MoO3 catalyst was successfully synthesized by the hydrothermal coating strategy, and its physicochemical properties and catalytic properties in methane aromatization were investigated using a physically‐blended ZSM‐5/MoO3 catalyst as a comparison. Multitechniques including XRD, SEM, TEM, EDS, N2 adsorption, ICP, IR and IG were employed to investigate the characteristics of methane aromatization reaction and the deactivation of carbon deposits. At the reaction temperature of 700 °C and a space velocity of 2400 mL g−1 h−1, methane conversion and aromatics selectivity of the core‐shell ZSM‐5@MoO3 catalyst were 11.3 % and 88.1 %, respectively, which were higher than those of the physically‐blended ZSM‐5/MoO3 catalyst by 3.1 % and 14.8 %, respectively. The special reaction pathway of core (ZSM‐5, acid sites)‐shell (MoO3, Mo sites) and the relatively close proximity between MoO3 and ZSM‐5 were mainly responsible for the excellent properties in the methane aromatization reaction. At the same time, the formation of the micro‐mesoporous property accelerated the mass‐transfer rate and inhibited the formation of carbonaceous deposition, greatly improving the stability of methane aromatization. Thanks to its core‐shell structure, ZSM‐5@MoO3 catalyst showed the excellent properties in methane aromatization.

Deuteration of Arylthianthren-5-ium Salts in CD3OD.

Deuteration of arylthianthren-5-ium triflates with CD3OD or CD3OD/CD3COCD3 in the presence of Cs2CO3 by palladium catalysis or photoirradiation allowed the convenient synthesis of deuterated arenes in good yields. The Pd-catalyzed reaction generally gave better yields than the photoinduced deuteration, but exceptions also exist. They could complement each other in some cases. These reactions featured eco-friendly conditions, simplicity, inexpensive deuterium sources, good functional group tolerance, and a range of substrates. Since arylthianthren-5-ium salts could be readily synthesized from arenes and thianthrene 5-oxide, this protocol provided a formal aromatic C-H deuteration with high selectivity, enabling efficient deuterium labeling of multifunctionalized arenes and drug molecules.

Boosting zinc storage in potassium-birnessite via organic-inorganic electrolyte strategy with slight N-methyl-2-pyrrolidone additive

The environmental-friendly and inexpensive birnessite is deemed as a potential cathode material for aqueous Zn-ion batteries (AZIBs). However, its electrochemical property is mainly enslaved to the unstable interlayer structure and side reaction aggravated by aqueous solvation. Herein, a potassium-birnessite (K0.14MnO1.96) cathode is prepared with a convenient one-pot hydrothermal synthesis, and a genuine insight into strengthening Zn2+energy storage efficiency via desolvation strategy with a low concentration of N-methyl-2-pyrrolidone (NMP) additive is proposed, which is also supported by the density functional theory (DFT) calculation. According to the result, the N-6 sample with enhanced kinetics and pseudocapacitance characteristics exhibits an optimum performance including terrific coulombic efficiency (CE) of ∼ 99.9%, impressive specific energy of 425.66 Wh kg−1, and long cyclic stability of 95.96% at 1 A g−1 after 2000 charge-discharge cycles, and specifically the cathodic by-product Zn4SO4(OH)6·4H2O as a major factor leading to properties deterioration for AZIBs is barely visible in the N-6 sample. Hence, this work opens up a simple but novel perspective of solvation barrier remission via organic-inorganic electrolyte strategy to promote aqueous zinc storage in birnessite.

Synthetic Optimizations for Gram-Scale Preparation of 1-O-Methyl d-Glycero-α-d-gluco-heptoside 7-Phosphate from d-Glucose.

Heptose phosphates-unique linkers between endotoxic lipid A and O-antigen in the bacterial membrane-are pathogen-associated molecular patterns recognized by the receptors of the innate immune system. Understanding the mechanisms of immune system activation is important for the development of therapeutic agents to combat infectious diseases and overcome antibiotic resistance. However, in practice, it is difficult to obtain a substantial amount of heptose phosphates for biological studies due to the narrow scope of the reported synthetic procedures. We have optimized and developed an inexpensive and convenient synthesis for the first performed gram-scale production of 1-O-methyl d-glycero-α-d-gluco-heptoside 7-phosphate from readily available d-glucose. Scaling up to such amounts of the product, we have increased the efficiency of the synthesis and reduced the number of steps of the classical route through the direct phosphorylation of the O6,O7-unprotected heptose. The refined method could be of practical value for further biological screening of heptose phosphate derivatives.

Ligand-enabled stereodivergence in nickel-catalyzed regioselective hydroboration of internal allenes

•Regio- and stereoselective hydroboration of internal allenes •Stereodivergent synthesis of trisubstituted alkenylboronates •Isolation and characterization of nickel-allene and nickel-olefin intermediates •In-depth mechanistic and kinetic studies Developing protocols for stereodivergent synthesis of multi-substituted alkenylboronates will simplify and unify the synthesis of Z- and E-stereoisomers of multi-substituted alkenes. Although tremendous efforts have been made to devise stereoselective approaches to access Z- or E-alkenylboronates, catalyst-controlled stereodivergence in their synthesis remains extremely rare. Herein, we demonstrate that such stereodivergence can be achieved for nickel-catalyzed hydroboration of internal allenes, which enables convenient synthesis of both stereoisomers of trisubstituted alkenylboronates from the same starting reagents. Mechanistic studies reveal that these nickel-catalyzed allene hydroboration reactions do not follow conventional hydrometallation or borylmetallation pathways with metal-hydride or metal-boryl intermediates. On the basis of the synthesis of potential nickel intermediates and their stoichiometric reactions, we propose new pathways for this nickel-catalyzed allene hydroboration, involving initial complexation of allenes to low-valent nickel catalysts followed by the stereo-determining reaction of bisphosphine-ligated nickel-allene intermediates with pinacolborane (HBpin) to form nickel-olefin compounds, which contain coordinated Z- or E-alkenylboronates. Developing protocols for stereodivergent synthesis of multi-substituted alkenylboronates will simplify and unify the synthesis of Z- and E-stereoisomers of multi-substituted alkenes. Although tremendous efforts have been made to devise stereoselective approaches to access Z- or E-alkenylboronates, catalyst-controlled stereodivergence in their synthesis remains extremely rare. Herein, we demonstrate that such stereodivergence can be achieved for nickel-catalyzed hydroboration of internal allenes, which enables convenient synthesis of both stereoisomers of trisubstituted alkenylboronates from the same starting reagents. Mechanistic studies reveal that these nickel-catalyzed allene hydroboration reactions do not follow conventional hydrometallation or borylmetallation pathways with metal-hydride or metal-boryl intermediates. On the basis of the synthesis of potential nickel intermediates and their stoichiometric reactions, we propose new pathways for this nickel-catalyzed allene hydroboration, involving initial complexation of allenes to low-valent nickel catalysts followed by the stereo-determining reaction of bisphosphine-ligated nickel-allene intermediates with pinacolborane (HBpin) to form nickel-olefin compounds, which contain coordinated Z- or E-alkenylboronates.

Dimethyl 3,7-diamino-4,8-bis((2-methoxy-2-oxoethyl)thio)benzo[1,2-b:4,5-b’]dithiophene-2,6-dicarboxylate

The convenient and multigram synthesis of a linear benzo[b]dithiophene (BDT) structure is proposed (dimethyl 3,7-diamino-4,8-bis((2-methoxy-2-oxoethyl)thio)benzo[1,2-b:4,5-b’]dithiophene-2,6-dicarboxylate). The starting materials are commercially available 2,3,5,6-tetrachloroterephthalonitrile and methyl 2-mercaptoacetate, which undergo aromatic substitution, followed by a cyclization reaction in basic conditions to form suitable BDT for potential optoelectronic applications.

Synthesis of Arylidenehydrazinyl-4-methoxyphenylthiazole Derivatives: Docking Studies, Probing Type II Diabetes Complication Management Agents.

Thiazole has been a key scaffold in antidiabetic drugs. In quest of new and more effective drugs a simple, efficient, high yielding (67-79 %) and convenient synthesis of arylidenehydrazinyl-4-methoxyphenyl)thiazoles is accomplished over two steps. The synthesis involved the condensation of aryl substituted thiosemicarbazones and 2-bromo-4-methoxyacetophenone in absolute ethanol. The structures of the resulting thiazoles are in accord with their UV/VIS, FT-IR, 1 H-, 13 C-NMR and HRMS data. All compounds were evaluated for alpha(α)-amylase inhibition potential, antiglycation, antioxidant abilities and biocompatibility. The compounds library identified 2-(2-(3,4-dichlorobenzylidene)hydrazinyl)-4-(4-methoxyphenyl)thiazole as a lead molecule against α-amylase inhibition with an IC50 of 5.75±0.02 μM. α-Amylase inhibition is also supported by molecular docking studies against α-amylase. All the obtained thiazoles also showed promising antiglycation activity with 4-(4-methoxyphenyl)-2-{2-[2-(trifluoromethyl)benzylidene]hydrazinyl}thiazole exhibiting the best inhibition (IC50 = 0.383±0.001 mg/mL) compared to control. The tested compounds are also biocompatible at the concentration used i. e., 10 μM.

Zn-Catalyzed Regioselective and Chemoselective Reduction of Aldehydes, Ketones and Imines.

An operationally convenient Zn-catalyzed synthesis of alcohols by the reduction of aldehydes, ketones, and α,β-unsaturated aldehydes/ketones is reported. It is a rare example of using mild and sustainable HBpin as a reductant for catalytic reduction of carbonyl compounds in the absence of acid or base as hydrolysis reagent. The reaction is upscalable and proceeds in high selectivity without the formation of boronate ester by-products, and tolerates sensitive functionalities, such as iodo, bromo, chloro, fluoro, nitro, trifluoromethyl, aminomethyl, alkynyl, and amide. The Zn(OAc)2/HBpin combination has been also proved to be chemoselective for the C=N reduction of imine analogs.

Three-Component Synthesis of Pyridylacetic Acid Derivatives by Arylation/Decarboxylative Substitution of Meldrum's Acids.

A convenient and simple three-component synthesis of substituted pyridylacetic acid derivatives is reported. The approach centers on the dual reactivity of Meldrum's acid derivatives, initially as nucleophiles to perform substitution on activated pyridine-N-oxides, then as electrophiles with a range of nucleophiles to trigger ring-opening and decarboxylation.

Convenient Synthesis of Ellagic Acid from Methyl Gallate and SARS-CoV-2 3CLpro Antiviral Activity

AbstractA practical synthesis of ellagic acid has been achieved from methyl gallate by a proposed synthetic route of five steps, consisting of ketal protection, regioselective bromination, bis-lactonization, C–C bond formation between the aromatic rings of the galloyl groups, and ketal deprotection, in 38% overall yield. Ellagic acid showed a slight inhibitory activity against SARS-CoV-2 3CLpro.

Preparation of 5-Selenocyanatouracil by a more convenient method and evaluation of some pharmacological properties

A convenient method for preparation of 5-Selenocyanatouracil (5-SeU), this compound gains importance because it is similar to 5-Fluorouracil which is one of the famous uracil derivatives as an anticancer drug. Some of invitro pharmacological activities such as DPPH antioxidant effects and antimicrobial activity, in addition to median lethal dose (LD50) were estimated. The study aimed to use a convenient synthesis procedure, and evaluation of in vitro pharmacological activity, also to determine the median lethal dose of 5-SeU. 5-SeU synthesis was carried out in very good yield through a direct reaction between 5-Iodouracil and freshly prepared potassium selenocyanate in refluxing aqueous solution to give light-gray crystalline. Antimicrobial measured by disc diffusion method. LD50was determine using Albino rats. 5-SeU compound was branded by FT-IR; 13C- NMR and 1H- NMR spectroscopic data. The results showed no antibacterial effects for most of test bacteria with a low inhibition effect on Staph. Aureus, and Pseudomonas aeruginosa, with moderate inhibition zone at candida culture.

Cu-Catalyzed Three-Component Cascade Synthesis of 1,3-Benzothiazines from ortho-Aminohydrazones and Bromodifluoroacetamides.

An efficient and convenient synthesis of benzo[d][1,3]thiazine has been developed by employing a copper-catalyzed transformation of readily available ketone-derived hydrazones with elemental sulfur and bromodifluoroalkylative reagents. The strategy involves an S8-catalyzed selective triple-cleavage of bromodifluoroacetamides, which acts as a C1 synthon at the 2-position of benzo[d][1,3]thiazine. A mechanism proceeding through a Cu-carbene intermediate is proposed for the C-S bond formation.

Concise Total Syntheses of Amorfrutin A and B

AbstractThe convenient and facile syntheses of amorfrutin A and amorfrutin B have been realized in five steps starting from commercially available 2,4‐dimethoxybenzoic acid with an overall yield of 32 % and 22 %, respectively. The key steps involved Ru(II)‐catalyzed olefination and straightforward C‐alkylation.

A convenient synthesis of 3-arylideneindolin-2-ones and evaluation of their photoelectrochemical properties

A convenient synthesis of 3-arylideneindolin-2-ones and evaluation of their photoelectrochemical properties

Zn catalyzed a simple and convenient method for thiourea synthesis

A straightforward and convenient synthesis of symmetrical and unsymmetrical thiourea derivatives by the reaction of primary amines and carbon disulfide in the presence of a Zn catalyst is presented. Under modest reaction conditions, a range of biologically relevant thiourea derivatives can be produced in good to outstanding yields without a lengthy work-up. A variety of primary aliphatic and aromatic amines with various substituted functional groups were transformed into thiourea derivatives. Zn-mediated symmetric thiourea creation occurs at room temperature for aliphatic amines, whereas for aromatic amines it occurs at 60°C. However, unsymmetrical thiourea for aliphatic amines occurs at 0°C. Benefits of this method include environment-friendly reaction conditions, sustainability, and enumerating tolerance of functional groups such as hydroxyl and halides. Experimental observations were rationalized by DFT calculations based on transition structures and zwitterionic intermediate stabilities.

Regioselective Synthesis of Functionalized Pyrrolo[1,2-a]pyrazine-3,6(2H,4H)-diones via Tandem Post-Ugi Cyclization and Gold(I)-Catalyzed Annulation

A convenient synthesis of less explored pyrrolo[1,2-a]pyrazine-3,6(2H,4H)-diones is described in two steps from Ugi adducts. The method involves acid-mediated cyclization of Ugi adducts to form dihydropyrazinones followed by gold(I)-catalyzed regioselective annulation. The generality of the transformation was established by reacting a variety of substituted dihydropyrazinones under the optimized reaction conditions to form densely functionalized pyrrolo[1,2-a]pyrazine-3,6(2H,4H)-diones in good-to-excellent yields. It was also observed some of the acetone-derived Ugi adducts furnish 7-acyl-pyrroloimidazolones as a byproduct during TFA-mediated cyclization via alkyne-carbonyl metathesis and condensation.