Maleic Anhydride Derivatives Research Articles

Diels–Alder reactions between maleic anhydride and furan derivatives in supercritical CO2

A comparative analysis of the reactions between maleic anhydride and furan derivatives is presented in near and supercritical carbon dioxide and traditional organic solvents. Reaction kinetics were monitored by UV-vis absorbance spectroscopy in conjunction with an optimization technique which greatly simplified the experimental approach. In all of the reactions studied, supercritical carbon dioxide proved to facilitate a rate enhancement over conventional organic solvents. The reaction between maleic anhydride and furfuryl alcohol at 69 bar and 35 °C was found to proceed 10 times faster in CO2 compared to reactions carried out in diethyl ether. All kinetic results were obtained from reactions undertaken in true homogeneous one phase fluid systems. The results achieved further indicate the potential of using carbon dioxide as a medium to carry out such chemical transformations through more environmentally acceptable processes.

A Comparative Study of the Spectral and Kinetic Properties of Photochromic Dihetarylethenes Based on Maleic Anhydride and Maleimide

A comparative spectral-kinetic study of the photochromism of a number of new thermally irreversible 1,2-diarylethenes, considered as possible candidates for 3D optical data storage, is performed. The diarylethenes studied contain as bridges either maleic anhydride or maleimide derivatives. A relation between the structure of the bridges and substituents of these compounds and their photochromic properties is established.

One Pot Synthesis of Photochromic Maleic Anhydride Derivatives

Abstract Photochromic 2-aryl-3-(1-propenyl)maleic anhydride derivatives were synthesized by one pot synthesis and their photochromic performance was examined in solution.

Use of reactive surfactants in basalt fiber reinforced polypropylene composites

AbstractBasalt fibers, similarly to other silicate fibers, can be introduced into both thermoplastic and thermosetting polymer matrices. In this work some basalt fiber reinforced polypropylene composites were investigated. The fiber‐matrix adhesion was improved by commercial and non‐commercial maleic anhydride derivatives. The latter types, called reactive surfactants, were prepared in laboratory scale and the progress of the syntheses was determined by Raman microscopy. The additives allowed performing reactive interface modification during the compounding process. Due to the interface modification with the additives in low concentration the mechanical properties improved. The boundary layers on the surface of the reinforcing fibers were observed using scanning electron microscopy (SEM).

Endosomolysis by masking of a membrane-active agent (EMMA) for cytoplasmic release of macromolecules.

Endosomolysis, a critical barrier to efficient delivery of macromolecules such as nucleic acids, has been breached using a novel approach: endosomolysis by masking of a membrane-active agent (EMMA). To demonstrate the concept of EMMA, a cationic membrane-active peptide, melittin, was reversibly inhibited using a maleic anhydride derivative. At neutral pH, the lysines of melittin are covalently acylated with the anhydride, thereby inhibiting melittin's membrane disruption activity. Under acidic conditions such as those present within endosomes, the amide bond of the maleamate is cleaved, thus unmasking melittin. The active melittin can then disrupt the endosomal membrane resulting in release of biologically active molecules into the cytoplasm. This approach avoids cellular toxicity by restricting melittin's activity until it reaches the endosomal compartment. The utility of this approach was demonstrated by delivery phosphorodiamidate morpholino oligonucleotides (PMOs).

Chain End Functionalization in Nitroxide-Mediated “Living” Free Radical Polymerizations

A novel method for the functionalization of vinyl polymers prepared by nitroxide-mediated living free radical procedures is reported. This strategy is based on the controlled monoaddition of maleic anhydride and maleimide derivatives to the alkoxyamine chain end followed by elimination of the mediating nitroxide radical. This allows the introduction of a wide variety of functional groups with high efficiency, while at the same time permitting the alkoxyamine functional group to be removed and the thermal stability of the polymer chain to be increased.

A Facile Synthesis of a (±)-2,3-Disubstituted Maleic Anhydride Segment of Tautomycin

A convenient method for construction of a (±)-2,3-disubstituted maleic anhydride segment of antibiotic tautomycin is reported. The key steps involved in the synthesis are chemoselective condensation of diethyl malonate with 2-(bromomethyl)-3-methylmaleic anhydride (3) and regioselective NBS-bromination of the maleic anhydride derivative 7.

ChemInform Abstract: A Novel Maleic Anhydride Derivative from the Fungus Talaromyces sp. No. 10092.

A new maleic anhydride derivative 1 (FR222398) was isolated from fermentations with the fungus Talaromyces sp. No. 10092. The structure of 1 was determined based on spectroscopic analysis and chemical conversion. The sodium salt of 1 exhibited a dispersant activity toward kaolin suspension.

A Novel Maleic Anhydride Derivative from the Fungus Talaromyces sp. No. 10092

Abstract A new maleic anhydride derivative 1 (FR222398) was isolated from fermentations with the fungus Talaromyces sp. No. 10092. The structure of 1 was determined based on spectroscopic analysis and chemical conversion. The sodium salt of 1 exhibited a dispersant activity toward kaolin suspension.

Investigation of the radical copolymerization and terpolymerization of maleic anhydride and norbornenes by anin situ1H NMR analysis of kinetics and by the mercury method: Evidence for the lack of charge-transfer-complex propagation

The radical copolymerization of electron-deficient maleic anhydride (MA) and electron-rich norbornene (NB) derivatives with 2,2′-azobis(isobutyronitrile) (AIBN) in dioxane-d8 has been monitored in situ by 1H NMR spectroscopy with free induction decays recorded every 30 min at 60, 70, or 84 °C. The ratios of the monomer pairs were varied in some cases. The NB derivatives employed in this study included bicyclo[2.2.1]hept-2-ene (NB), t-butyl 5-norbornene-2-carboxylate, methyl 5-norbornene-2-methyl-2-carboxylate, and ethyl tetracyclo[4.4.0.12,5.17,10]dodec-3-ene-8-carboxylate. Decomposition of AIBN, consumption of the monomers, feed ratios, endo/exo ratios, copolymer compositions, and copolymer yields were studied as a function of polymerization time. Furthermore, a homopolymerizable third monomer (t-butyl methacrylate, methacrylic acid, t-butyl acrylate, or acrylic acid) was added to the NB/MA 1/1 system, revealing that the methacrylic monomer polymerizes rapidly in the early stage and that the ratio of MA to NB in the terpolymer strongly deviates from 1/1. In contrast, however, the acrylic monomers are more uniformly incorporated into the polymer. Nevertheless, these studies indicate that MA and NB do not always behave as a pair in radical polymerization and disproves the commonly believed charge-transfer mechanism. Electron-deficient fumaronitrile was also included in the kinetics study. To further understand the copolymerization mechanism, MA and NB were competitively reacted with a cyclohexyl radical generated by the treatment of cyclohexylmercuric chloride with sodium borohydride (mercury method). A gas chromatographic analysis of the reaction mixtures has revealed that a cyclohexyl radical reacts with MA almost exclusively in competition and that the cyclohexyl adduct of MA essentially accounts for all the products in a mass balance experiment, eliminating a possibility of the formation of an adduct involving the MA–NB charge-transfer complex. Thus, the participation of a charge-transfer complex in the copolymerization of MA and NB cannot be important. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3521–3542, 2000

Chiral Phosphito−Thioether Complexes of Palladium(0). Comments on the Pd, Rh, and Ir Regio- and-Enantioselective Allylic Alkylations of PhCHCHCH(OAc)R, R = H, Me, Et

The new chiral auxiliary (R)-2-ethylthio-1-(phenylethyl)-(R)-binaphthyl phosphite, 1, and three stable Pd(0) olefin complexes containing this chelate, 2−4, have been synthesized. The structure of the maleic anhydride complex 3 has been determined by X-ray diffraction methods. Solution details for 2−4 and aspects of their dynamics have been elucidated via 2-D NMR spectroscopy. The fumaronitrile complex 2 exchanges intramolecularly, whereas the maleic anhydride and pentenedione derivatives, 3 and 4, respectively, exchange intermolecularly. Ligand 1 has been used as auxiliary in the Pd, Rh, and Ir regio- and enantioselective allylic alkylation reactions of PhCHCHCH(OAc)R, R = H, Me, Et, with the anion of dimethyl malonate. Modest to good selectivities are reported.

1 H and 13 C NMR spectra for a series of arylmaleamic acids, arylmaleimides, arylsuccinamic acids and arylsuccinimides

The 1H and 13C NMR spectra of 17 succinic anhydride derivatives and 25 maleic anhydride derivatives were completely assigned using one- and two-dimensional NMR techniques. Copyright © 1999 John Wiley & Sons, Ltd.

(2 + 2) Photosensitized cycloadditions of maleic anhydride derivatives to selenophene and tellurophene derivatives

The photoadditions of 2,3-dimethylmaleic anhydride to selenophene (C. Rivas, D. Pacheco, F. Vargas, J. Heterocycl. Chem. 17 (1980) 1151) and selenophthene (D. Pacheco, C. Rivas, F. Vargas, J. Heterocycl. Chem. 20 (1983) 1465) and of 2,3-dimethylmaleimide to selenophene and 3,4-dimethylselenophene (C. Rivas, F. Vargas, A. Torrealba, D. Pacheco, R. Machado, G. Aguiar, Monatsh. Chem. 125 (1994) 1153) in benzophenone-photosensitized reactions have been carried out successfully in this laboratory. This reaction has been extended to other methyl-substituted selenophenes and, during the course of this investigation, it was observed that the compounds under study showed a somewhat different behaviour from those mentioned above. The new photoproducts obtained are reported and an attempt is made to give a general view of the photochemical behaviour of methyl selenophenes. Furthermore, tellurophene and benzo(b)tellurophene were also tested as substrates for these (2 + 2) cycloaddition reactions

Cycloaddition Reactions of Dicarbonyl(η5-cyclopentadienyl)(η1-indenyl)iron

[3 + 2]-Cycloaddition reactions of the title compound with maleic anhydride and tetracyanoethylene form benzonorbornene derivatives. Dimethyl fumarate, dimethyl acetylenedicarboxylate, and diethyl azodicarboxylate do not react analogously. The reduced reactivity of indenyl−Fp compared to cyclopentadienyl−Fp supports the proposal that the latter reacts with electron-deficient alkenes by [4 + 2]-cycloaddition rather than [3 + 2]-cycloaddition.

Bis-esters from maleic anhydrides under neutral conditions: Protection of the anhydride of the natural product cornexistin

Trimethylsilyldiazomethane converts maleic anhydride derivatives in alcoholic THF to bisesters. The highly acid and base sensitive natural product cornexistin was converted to its bis-methyl ester in 70–75% yield and to the mixed benzyl/methyl ester in 61% yield. The mixed ester can be converted back to cornexistin via transfer hydrogenation.

Electro-organic reactions. Part 41. Diels-Alder reactions of o-quinodimethanes from the cathodic reduction of α, α′-dibromo-1,2-dialkylbenzenes

Cathodic reduction of α, α′-dibromo-1,2-dialkylbenzenes in DMF containing Et 4N + Br − as supporting electrolyte, in the presence of dienophiles ( e.g. maleic anhydride derivatives), yielded Diels-Alder adducts of o-quinodimethanes. Selective reduction of the benzylic dibromides was often possible even when their irreversible cyclic voltammetric reduction peak potentials were more negative than the E o values for the anhydrides. This might be a consequence of redox catalysis, with the anhydrides having a dual role as mediators and dienophiles.

Determination of Urinary Oxalate Using Banana Oxalate Oxidase: Comparison with Immobilized Enzyme

Abstract Oxalate oxidase, isolated from banana fruit peel, is immobilized on various supports and the efficacies of these derivatives in determining urinary oxalate are compared. Banana oxalate oxidase, when complexed with its antiserum, is found to have higher specific activity, greater stability, broader range of pH profile and higher resistance to thermal inactivation. Oxalate oxidase, when immobilized in acrylamide membrane strip, is found to be stable and easy to use in the determination of urinary oxalate. These two preparations compare well with that of soluble enzyme in sensitivity, accuracy and reliability. However, both hydrazide bead-linked oxalate oxidase and ethylene maleic anhydride derivative of oxalate oxidase are found to be unsuitable for the determination of urinary oxalate.

Langmuir‐Blodgett films of liquid‐crystalline polymer with cholesterol side‐groups as electron resists

Langmuir-Blodgett (LB) films are often compared to liquid crystals. The common feature of their structure two-dimensional order makes these materials similar I ) . So it seems very attractive to fabricate LB films of liquid crystals with their virtue to form well-ordered two-dimensional layers. On the other hand, in recent years, the growing interest in LB films of polymers also has been shown2-’). Such films have received considerable attention due to their stability a t high temperature, chemical resistance, good mechanical and dielectric properties. At the same time there exists a class of materials, that exhibits both liquid-crystal and polymer properties. These are comb-like liquid-crystalline polymers. Earlier, LB films of the copolymers of maleic anhydride derivatives with mesogenic vinyl monomers and mesogenic maleic anhydride derivatives with styrene have been created, in order to use them as insulating layers, lithographic resists and optical waveguides in opto-electronic devicess-lO). In ref. I t ) LB films of polysiloxane with mesogenic chromophoric side fragments are described. This paper is devoted to the investigation of the possibility of cholesteric liquid-crystalline LB monoand multilayer creation and to the application of these films for obtaining negative electron resists. The polymer used was poly{l-[ lO-(IOa-cholest-5-en-3/3-yloxycarbonyl)decyloxycarbonyl]ethylene) [poly(cholesteryl 1 1 -acr yloxyundecanoate)] with a molecular weight of about lo5:

Intrinsically photosensitive polyimides: Approaches to fluorinated homologs

AbstractCyclobutane tetracarboxylic acid dianhydrides, which were prepared via photodimerization of maleic anhydride or methylmaleic anhydride, gave high molecular weight film‐forming polyimides with oxydianiline. The resulting polyimides were found to be photosensitive, presumably because of retrocyclization of the cyclobutane ring. Despite the presence of the cyclobutane ring, the polyimides show good thermal stability. In an effort to enhance the thermal stability and lower the dielectric constant of these polyimides, an approach was made to prepare the fluorinated analogs of the cyclobutane dianhydride monomers via the preparation and photodimerization of fluorinated maleic anhydride derivatives. Thus, both fluoromaleic and difluoromaleic anhydrides were photolyzed to give the target monomers. The proposed application of these monomers, however, has yielded disappointing results due to complications in their synthesis and attempted polymerization.

Esters of α‐sulfomaleic anhydride as powerful electrophiles for polyolefin functionalization

AbstractNew electrophilic derivatives of maleic anhydride were synthesized to test their reactivity in ene reactions with the terminal double bond of hydrocarbon polymers. The methyl ester and new ethyl ester of sulfomaleic anhydride (SMA) were reacted with 2,2,4‐trimethyl‐1‐pentene 3, which is a model compound for the end group of the hydrocarbon polymers. The SMA esters were more oleophilic than SMA itself, but many side reactions occurred. Higher alkyl esters of SMA could not be synthesized. Two silyl esters of SMA, trimethylsilyl and t‐butyldiphenylsilyl, were also synthesized and reacted with 3; ene reactions proceeded well in bulk, but the ene adducts decomposed upon heating. The powerful dienophilic character of these SMA esters was demonstrated by a series of [4 + 2] cycloadditions.