Presence Of Tert-butyl Hydroperoxide Research Articles

Preparation and Characterization of Poly(Methyl Methacrylate) Grafted Natural Rubber Latex Films

Poly(methyl methacrylate) (PMMA) grafted natural rubber (NR) latex was successfully prepared and solely exploited even at high MMA concentration (1.5 mol/kg-rubber) to make coherent and uniform vulcanized films without blending with other polymer to achieve excellent physical properties. High ammonia natural rubber (HANR) latex was subjected to graft-copolymerization with methyl methacrylate (MMA) monomer in the presence of tert-butyl hydroperoxide (TBHP) and tetraethylenepentamine (TEPA). High conversion, i.e., 85.12 mol%, and grafting efficiency, i.e., 92.70 mol%, were obtained at 1.5 mol/kg-rubber MMA. The resulting gross PMMA grafted NR (1.5PMMA) latex was then compounded, dipped, and vulcanized to produce thin films. The tensile strength and modulus at 300 percent (M300) of vulcanized 1.5PMMA film were superior to vulcanized HANR film by 1-fold. While elongation at break (EB) was identical to each other due to the high gel content in both vulcanized films. Besides, the vulcanized 1.5PMMA film absorbed less oil compared to HANR film. The thermal stability of vulcanized 1.5PMMA film was found to be higher than that of vulcanized HANR film. Hence, it can be deduced that controlling the graft-copolymerization of PMMA in NR latex is the key to produce coherent thin films with improved properties at higher PMMA content.

Supported Copper Nanoarchitecture for Selective Ethylbenzene Oxidation (EBO) Reaction

Copper-based (Cu-NP) were uniformly dispersed on various inorganic supports (alumina, silica, titania, and zirconia) were prepared by the reverse microemulsion technique. These nanoparticles were used for the selective oxidation of ethylbenzene (EB) to produce acetophenone (AP) as the main product in the presence of Tert-butyl hydroperoxide(TBHP) as an oxidant. This study focused on creating Cu-nanoparticles evenly dispersed on alumina using varying Cu-loadings (5%, 10%, and 15% wt.) and Brij-35 as the surfactant. The resulting catalytic material was characterized using various physicochemical techniques like XRD, FESEM, HRTEM, XPS and physisorption techniques. Various parametric studies were conducted, such as the effects of temperature, catalyst support, catalyst loading, and TBHP loading to optimize the EB conversions and AP selectivity. Among the various catalyst loadings, 15% CuO/Al2O3 (15% of the copper content) nanocomposites showed exceptional performance, with the highest EB conversion rate (99.7%) and AP selectivity (98.5%) compared to other nanocomposites. The catalyst's stability and recyclability over four cycles were attributed to the strong copper oxide-alumina interaction. These findings suggest that this nanocomposite material is a promising candidate for catalytic applications, offering high selectivity and consistent EB conversion rates.

Platinum meso-tetraphenylporphyrin (Pt(II)TPP) mediated the efficient oxidation of alkyl aromatics to ketones in the presence of tert-butyl hydroperoxide

Platinum meso-tetraphenylporphyrin (Pt(II)TPP) mediated the efficient oxidation of alkyl aromatics to ketones in the presence of tert-butyl hydroperoxide

Protection-Free, Two-step Synthesis of C5-C Functionalized Pyrimidine Nucleosides.

A simple, reliable, and efficient method for the gram-scale chemical synthesis of pyrimidine nucleosides functionalized with C5-carboxyl, nitrile, ester, amide, or amidine, starting from unprotected uridine and cytidine, is described. The protocol involves the synthesis of 5-trifluoromethyluridine and 5-trifluoromethylcytidine with Langlois reagent (CF3 SO2 Na) in the presence of tert-butyl hydroperoxide and subsequent transformation of the CF3 group to the C5-C 'carbon substituents' under alkaline conditions. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Synthesis and characterization of 5-trifluoromethyluridine (5-CF3 U) and 5-trifluoromethylcytidine (5-CF3 C) Basic Protocol 2: Conversion of 5-CF3 U and 5-CF3 C to several C5-substituted ribonucleosides.

Catalytic oxidative cyclization of α-carbonyl-γ-alkynyl sulfoxonium ylides for stereospecific synthesis of (1Z,3Z)-1,3-bismethyleneisobenzofurans

A new copper(ii)-catalyzed reaction of α-carbonyl-γ-alkynyl sulfoxonium ylides with sulfonyl hydrazides in the presence of tert-butyl hydroperoxide (TBHP) is reported, regio- and stereoselectively accessing (1Z,3Z)-1,3-bismethyleneisobenzofurans.

Synthesis of Fluoromethylated Chromones and Their Heteroatom Analogues via Sodium Fluoromethanesulfinate-Enabled Direct Fluoromethylation.

An array of biologically interesting tri/difluoromethylated chromones and their heteroatom analogues were conveniently synthesized from the reaction of chromones and their heteroatom analogues with CF3SO2Na or HCF2SO2Na in the presence of tert-butyl hydroperoxide under mild conditions. A mechanistic pathway involving the generation of the electrophilic tri/difluoromethyl radical, followed with the radical substitution of chromones and their heteroatom analogues, was postulated.

Cu(II) Promoted C(sp3 )-H Activation in Unactivated Cycloalkanes: Oxo-Alkylation of Styrenes to Synthesize β-Disubstituted Ketones.

We report the Cu(II) catalyzed synthesis of β-disubstituted ketones from styrene via oxo-alkylation with unactivated cycloalkanes as the alkylating agent in presence of tert-butylhydroperoxide (TBHP) and 1-methylimidazole as oxidant and base respectively. β-disubstituted ketones are known to be synthesized by using either expensive Ru/Ir complexes, or low-cost metal complexes (e. g., Fe, Mn) with activated species like aldehyde, acid, alcohol, or phthalimide derivatives as the alkylating agent, however, use of unactivated cycloalkanes directly as the alkylating agent remains challenging. A wide range of aliphatic C-H substrates as well as various olefinic arenes and heteroarene (35 substrates including 14 new substrates) are well-tolerated in this method. Hammett analysis shed more light on the substitution effect in the olefinic part on the overall mechanism. Furthermore, the controlled experiments, kinetic isotope effect study, and theoretical calculations (DFT) enable us to gain deeper insight of mechanistic intricacies of this new simple and atom-economic methodology.

Amino-induced cadmium metal–organic framework based on thiazole ligand as a heterogeneous catalyst for the epoxidation of alkenes

Selective epoxidation of olefins is of high interest in the chemical industry due to the many applications of epoxides. This study reports on the synthesis of Cd-MOF, [Cd(DPTTZ)(5-AIP)] (IUST-1) (where DPTTZ = 2, 5-di (pyridine-4-yl) thiazolo [5, 4-d] thiazole, 5-AIP = 5-Aminoisophthalic acid), by a reflux method, which can be considered as a fast and simple process. The morphology and structure of the synthesized IUST-1 were determined by using FE-SEM (Field Emission Scanning Electron Microscopy), EDX (Energy Dispersive Analysis of X-ray), Mapping (Elemental Mapping), CHNS (Elemental analysis), XRD (X-Ray Diffraction), FT-IR (Fourier Transform Infrared), and TGA (Thermo Gravimetric Analysis). The epoxidation of cyclooctene was investigated using the activity of catalytic IUST-1. The results showed that in the presence of tert-butyl hydroperoxide and CCl4 in a 1:2 alkene/oxidant ratio, a high epoxide yield (99.8%) was obtained. In addition, IUST-1 can be easily separated by simple filtration and recycled five times successfully with a slight decrease in activity. This compound has some advantages such as high yield, short reaction time, and ease of reuse, which make it a suitable heterogeneous catalyst for the epoxidation of cyclooctene.

Synthesis of 6β-hydroxy androgens from a 3,5-diene steroid precursor to test for cytochrome P450 3A4-catalyzed hydroxylation of androstenedione

6β-Hydroxytestosterone is a biomarker for the activity of human cytochrome P450 3A4 (P450 3A4), the major drug metabolizing cytochrome P450 enzyme. Despite its significance, efficient routes for the chemical synthesis of 6β-hydroxytestosterone are rare. In this study, 6β-hydroxytestosterone was synthesized through the oxidation of a 3,5-diene precursor under the Uemura-Doyle reaction conditions using a dirhodium catalyst in the presence of tert-butylhydroperoxide. Mechanistic studies showed that some oxygen is incorporated from molecular oxygen and CH abstraction is partially rate-limiting. This reaction was used to synthesize 6β-hydroxyandrostenedione, which was used as a standard to test the hypothesis of whether P450 3A4 catalyzes the hydroxylation of androstenedione. Upon incubation of P450 3A4 with androstenedione, a hydroxylated product was formed, which matched the retention time of synthetic 6β-hydroxyandrostenedione. This reaction can be exploited to study other biochemical processes involving compounds with a 6 β -hydroxy-3-keto-Δ4 steroid backbone.

A New Method for the Synthesis of 1-Methyl-1H-indole-3-carboxylate Derivatives, Employing Copper(II)

AbstractWe report an efficient method for synthesizing 1-methyl-1H-indole-3-carboxylates by cross-dehydrogenative coupling. However, the coupling reactions are a way to functionalize the α-carbon of iminiums from tertiary amines. The synthesis of 1-methyl-1H-indole-3-carboxylates from N,N-dimethylaniline with bromoacetates has not been reported. In the present work, we describe a novel route for synthesizing 1-methyl-1H-indole-3-carboxylates with N,N-dimethylaniline and a wide range of phenyl bromoacetate derivatives. Features such as a simple procedure and good to excellent yields (69–90%) make this method a highly efficient procedure for the preparation of indole derivatives using Cu(OAc)2·H2O as a catalyst in the presence of tert-butyl hydroperoxide.

Ultrasonic irradiation-assisted MnFe2O4 nanoparticles catalyzed solvent-free selective oxidation of benzyl alcohol to benzaldehyde at room temperature.

Magnetic nanoparticles (NPs) play a vital role in heterogeneous catalysis because of their easy separation, and effective recyclability. Herein, we report the synthesis of MnFe2O4 NPs for use as catalysts in the selective oxidation of benzyl alcohol to benzaldehyde under mild conditions. The MnFe2O4 NPs have been synthesized by precipitation method followed by hydrothermal ageing at 180 °C for 4.0 h. We have investigated the effect of chitosan and carboxymethyl cellulose on the size or morphology of the formed MnFe2O4 NPs. The X-ray diffraction study confirms the formation of pure and crystalline MnFe2O4 with varying average crystallite sizes ranging from 18 to 28 nm based on the type of additive used. The electron microscopy study reveals that the additive plays a significant role in controlling the morphology of the formed MnFe2O4 NPs. These MnFe2O4 NPs exhibit superparamagnetic behaviour at room temperature and can effectively catalyze the solvent-free selective oxidation of benzyl alcohol to benzaldehyde in the presence of tert-butyl hydroperoxide at room temperature under ultrasonic irradiation. The developed protocol can be extended to various substituted benzyl alcohols having both the electron withdrawing and electron donating groups to afford moderate to excellent yield of the products. The catalyst is magnetically retrievable, highly stable, and can be reused up to the sixth run without significant loss of catalytic activity.

Quinazoline-Assisted Acylation with Aldehydes through Pd(II)-Catalyzed C(sp2)–H Activation

An efficient quinazoline-assisted ortho-aroylation of 4-phenylquinazolines with aromatic aldehydes has been developed using Pd(OAc)2 as the catalyst in presence of tert-butyl hydroperoxide (TBHP). This work provides an efficient strategy to synthesis of arylketones, giving yields of up to 90%. Meanwhile, the reaction system exhibits good functional group tolerance and a wide substrate scope. Radical trapping and control experiments suggest that the aroylation reaction involves a benzoyl radical pathway.

Metal-free one-pot synthesis of 2-substituted benzimidazoles from N-aryl imines and TMSN3

Iodine-catalysed efficient synthesis of 2-substituted benzimidazoles has been developed under aerobic condition. The one-pot oxidative cascade reactions of anilines, aldehydes and trimethylsilyl azide (TMSN3) lead to the benzimidazoles derivatives in the presence of tert-butyl hydroperoxide (TBHP). Iodine efficiently promoted the cross-coupling strategy to achieve the desired compounds via the sequential CH functionalization and cyclization. The present method features a greener approach, readily accessible reagents, broad substrate scope, high yields of the products, shorter reaction time and mild conditions.

A Metal-Free TBHP-Triggered Cascade Cyclization of 2-Arylindoles with Alcohols: Synthesis of Hydroxyalkylated Indolo[2,1-a]isoquinoline Derivatives

AbstractA practical method for the synthesis of hydroxyalkylated indolo[2,1-a]isoquinoline derivatives through the metal-free cascade cyclization of 2-arylindoles with alcohols in the presence of tert-butyl hydroperoxide (TBHP) is disclosed. The present method features transition-metal-free conditions and exceptional functional group tolerance. A series of valuable hydroxyalkylated indolo[2,1-a]isoquinoline derivatives bearing various functional groups is synthesized in moderate to excellent yields.

Greener and Efficient Epoxidation of 1,5-Hexadiene with tert-Butyl Hydroperoxide (TBHP) as an Oxidising Reagent in the Presence of Polybenzimidazole Supported Mo(VI) Catalyst

Alkene epoxidation with TBHP as an oxidising reagent using heterogeneous Mo(VI) catalyst is an environmentally friendly process since it eliminates acid waste and chlorinated by-products often associated with the conventional industrial method that uses stoichiometric peracid such as peracetic acid and m-chloroperbenzoic acid. Polybenzimidazole supported Mo(VI) complex, i.e., PBI.Mo has been successfully prepared, characterised and assessed for the epoxidation of 1,5-hexadiene in the presence of tert-butyl hydroperoxide (TBHP) as an oxidising reagent. A quadratic polynomial model has been developed, demonstrating the yield of 1,2-epoxy-5-hexene in four independent variables. The effects of different parameters such as reaction temperature, feed mole ratio of 1,5-hexadiene to TBHP, catalyst loading, and reaction time were studied. Response surface methodology (RSM) using Box-Behnken Design (BBD) was employed to study the interaction effect of different variables on the reaction response. This study presents the optimization of 1,5-hexadiene epoxidation in a batch reactor using TBHP as an oxidant and a polymer-supported Mo(VI) catalyst.

Manganese(II) coordination compounds of thiazole-hydrazone based NNN-donor ligands: Synthesis, characterization and catalytic activity

The reaction of Mn(OAc)2·4H2O with (E)-2-(2-(pyridin-2-ylmethylene)hydrazinyl)benzo[d]thiazole (HL1) and (E)-2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)benzo[d]thiazole (HL2), in methanol resulted in the formation of [Mn(L1)2]∙2CH3OH (1) and [Mn(L2)2] (2) as neutral mononuclear Mn(II) coordination compounds. These compounds were characterized by spectroscopic methods and their molecular structures were determined by single crystal X-ray diffraction analysis. In these compounds, the ligands are coordinated to the Mn(II) core via the nitrogen atoms of thiazole ring, pyridine ring and imine moiety and act as tridentate mononegative NNN-donor ligand. The manganese(II) coordination compounds were also used as catalyst for olefin oxidation in the presence of tert-butylhydroperoxide (TBHP) or H2O2 as oxidant. Under similar experimental conditions with equal loading of Mn(II) coordination compounds, the presence of TBHP resulted in higher oxidation conversion than H2O2.

TBAI-catalyzed C–N bond formation through oxidative coupling of benzyl bromides with amines: a new avenue to the synthesis of amides

A new green approach for the synthesis of amide through TBAI-catalyzed oxidative coupling of benzyl bromides with amine was developed in the presence of tert-butyl hydroperoxide (TBHP) as an oxidant. Various electron-donating and withdrawing groups containing benzyl bromides and various amines, were subjected to the reaction and transformed to the corresponding amide in good to excellent yields.

Catalytic asymmetric oxidative sulfenylation of β-ketocarbonyls using a chiral primary amine

Enantioselective oxidative construction of a C(sp3)–S bond has been achieved using a chiral primary amine catalyst in the presence oftert-butyl hydroperoxide and a catalytic amount of tetrabutylammonium iodide.

Selective Mild Oxidation of Anilines into Nitroarenes by Catalytic Activation of Mesoporous Frameworks Linked with Gold-Loaded Mn3 O4 Nanoparticles.

This work reports the synthesis and catalytic application of mesoporous Au-loaded Mn3 O4 nanoparticle assemblies (MNAs) with different Au contents, i. e., 0.2, 0.5 and 1 wt %, towards the selective oxidation of anilines into the corresponding nitroarenes. Among common oxidants, as well as several supported gold nanoparticle platforms, Au/Mn3 O4 MNAs containing 0.5 wt % Au with an average particle size of 3-4 nm show the best catalytic performance in the presence of tert-butyl hydroperoxide (TBHP) as a mild oxidant. In all cases, the corresponding nitroarenes were isolated in high to excellent yields (85-97 %) and selectivity (>98 %) from acetonitrile or greener solvents, such as ethyl acetate, after simple flash chromatography purification. The 0.5 % Au/Mn3 O4 catalyst can be isolated and reused four times without a significant loss of its activity and can be applied successfully to a lab-scale reaction of p-toluidine (1 mmol) leading to the p-nitrotulene in 83 % yield. The presence of AuNPs on the Mn3 O4 surface enhances the catalytic activity for the formation of the desired nitroarene. A reasonable mechanism was proposed including the plausible formation of two intermediates, the corresponding N-aryl hydroxylamine and the nitrosoarene.

Copper (II) Supported on a Post-Modified Magnetic Pectin Fe3O4@Pectin~Imidazole~SO3H-Cu(II): An Efficient Biopolymer-Based Catalyst for Selective Oxidation of Alcohols with Aqueous TBHP

Designing a catalyst that combines the activity, selectivity, simple recovery, and follows the green chemistry instructions is of great importance. In the present study, Fe3O4@Pectin~Imidazole~SO3H-Cu(II) was synthesized as an efficient and biopolymer-based magnetic catalyst for the oxidation of benzyl alcohols to aldehydes using tert-butyl hydroperoxide (TBHP) as an oxidant under solvent-free conditions. The catalyst was characterized using Fourier Transform Infrared Spectroscopy (FT-IR), Powder X-Ray Diffraction (XRD), Vibrating Sample Magnetometer (VSM), Field Emission scanning electron microscopy (FE-SEM), Energy dispersive spectroscopy (EDX), Transmission electron microscopy (TEM), and inductively coupled plasma (ICP) atomic emission spectroscopy. The results indicated that our catalyst was quite active in oxidizing the benzyl alcohols to their corresponding aldehydes in the presence of TBHP. The efficiency with low catalyst loading, convenient work-up, isolation of pure products, use of inexpensive metal instead of precious metals, solvent-free condition, use of eco-friendly support, and also the sustainability of catalyst up to at least 5 consecutive runs without a special drop-in activity are some of the remarkable advantages of this protocol.