Unsaturated Imides Research Articles

Can an aromatic ring alter the reactions of a nearby unsaturated imide? A study of the rate and selectivity of nitrile oxide cycloaddition reactions of acryloyl derivatives of the Rebek imide benzoxazole

Cycloadditions of acryloyl derivatives of the Rebek imide benzoxazole are extraordinarily stereoselective, but have rates and regioselectivities that otherwise parallel those of a simple achiral model. It appears that the benzoxazole ring of these compounds completely shields the inner face of the nearby alkene, but has no measurable effect on the rate of reactions on the outer face.

ChemInform Abstract: Asymmetric 1,4 Addition of Grignard Reagents to Chiral α,β‐ Unsaturated Imides in the Presence of Lewis Acids.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Diastereoselectivity in Iodotrimethylsilane‐Promoted Conjugate Additions of Organocopper Reagents to Chiral α,β‐ Unsaturated Imides and Amides.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Michael‐Type Addition of Phthalimide Salt to Chiral α,β‐ Unsaturated Imides.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Preparation of chiral indanones and dihydrocoumarins; application to synthesis of (+)-3-(2,6-dimethoxyphenyl) pentanoic acid

Chiral β-aryl carboxylic acids, prepared by Michael addition of organocuprates to chiral unsaturated imides, are transformed into chiral 3-alkyl-4-benzoyloxyindan-1-ones via two intramolecular acylations, with intermediate formation of chiral 3-alkylindanones and corresponding dihydrocoumarins. The 3-(S)-ethyl-4-benzoyloxyindanone is transformed into(+)-3-(S)-(2,6-dimethoxyphenyl)pentanoic acid.

Additions diastéréosélectives d'alkyl, alcényl, aryl et allyl cuprates à des imides chirales insaturées

Some diastereoselective conjugate additions of cuprates to chiral unsaturated imides bearing an imidazolidinyl group (from ephedrine and urea) show an impressive stereoselectivity. The chiral (internal auxiliary dependent) group is easily broken and recycled. The steric course of these reactions seems quite general and its development promising in synthesis.

Addition diastéréosélective d'allyl cuprates à des imides chirales insaturées

Abstract Magnesium diallyl cuprate will add to unsaturated imides, synthesized from chiral imidazolidinones, with very high diastereoselectivity and good yields. Isoprenyl cuprate gives addition with lower yield and stereoselectivity. The products show total allylic inversion.

Phosphorus-containing crosslinkable polymers for fire- and heat-resistant applications

New phosphorus-containing polyimides, polyamides and polyureas with saturated and unsaturated imide pendant groups were synthesized and characterized. Their synthesis was based on the monoamic acid derived from the reaction of tris(3-aminophenyl)phosphine oxide (TAPO) with an equimolar amount of succinic/maleic/nadic/itaconic anhydride. It was reacted subsequently with an equimolar amount of pyromellitic dianhydride (PMDA) or terephthaloyl chloride or tolylene diisocyanate. The crosslinkable polymers gave a network structure by curing at 230–260°C for 2.5 hr. Their thermal behaviour was investigated by DTA and TGA. All cured resins were stable up to 302–377 and 302–375°C in nitrogen and air, respectively. The char yield at 800°C in nitrogen was 51–75%. The physical and thermal properties depended on chemical structure.

Addition diastéréosélective d'organo-cuprates à des imides chirales insaturées

Some organocuprates add to unsaturated imides synthesized from chiral imidazolidones with very high diastereoselectivity.

Rheokinetic studies of the synthesis and properties of elastomers based on the oligodiene dihydrazides and unsaturated dicarboxylic imides

Rheokinetic methods were used to investigate the synthesis of elastomers from oligoisoprene dihydrazide and maleic acid bis-imides. The effect of the bis-imide structure, temperature-time parameters and the ratio of initial compounds in the rheokinetics of synthesis of cured compositions and on their deformation-strength properties has been investigated. A crosslinking mechanism is proposed, taking account of the reaction between terminal hydrazide and maleimide functional groups, as well as homopolymerization of maleimide. The feasibility of reinforcement of the obtained elastometer by active fillers has been ascertained.

Crosslinkable polyamide–imides

AbstractA series of polyamide–imides were prepared from aromatic diamines and substituted isophthaloyl chlorides containing unsaturated imide rings. Aromatic polyamides from isophthaloyl chloride were also prepared for comparison. The polyamide‐imides gave enhanced solubility compared to the aromatic polyamides and there was no deterioration in thermal stability or Tg. The PAIs were crosslinked by heating at 280°C/4 h under nitrogen. After this heat treatment all the PAIs became insoluble and their mechanical properties increased substantially; their thermal behavior, as measured by DSC and TGA, changed as a function of their chemical structure.

Synthesis of N2, N2? -alkylenediaspartimides

1. In the reactions of diamines with unsaturated cyclic imides, in the absence of moisture, the amino groups add at the double bond of the imides with the formation of the corresponding diimides. 2. N2,N2′:N2,N2′-Diethylenebis-N1-methylaspartimide is obtained in two stereoisomeric forms. 3. Twenty-two compounds, which have not been described earlier, have been synthesized and characterized.

Influence of the structure of unsaturated imides on their polymerizability and on the polymer properties

AbstractOn the basis of the comparison between the polymerization rates, intrinsic viscosities and molecular weights of the polymers of N‐substituted maleimides and citraconimides a conclusion is drawn that the methyl group in citraconimide causes a decrease in the reactivity of its double bond. Fractions of poly‐N‐isobutylmaleimide (P‐N‐IBMI) were investigated by the methods of translational diffusion, sedimentation, and flow birefringence. In the range of molecular weights from 0.19 × 106 to 3.6 × 106 relationships are obtained between the molecular weight M of the fractions investigated, their intrinsic viscosity [η], diffusion coefficient D, and sedimentation coefficient S. The hydrodynamic data obtained indicate that macromolecules of P‐N‐IBMI exhibit high rigidity due to the presence of cycles in their main chain. A marked optical anisotropy of the P‐N‐IBMI molecules is positive and indicates that molecular chains of P‐N‐IBMI in solution have a trans conformation.

Spectrophotometric investigation of the interaction of glutathione with maleimide and N-ethylmaleimide

The spectrophotometric investigation of the interaction of glutathione with maleimide and N-ethylmaleimide gave the following results: 1. 1. Glutathione interacts with maleimide and N-ethylmaleimide even at 4·10 −6 M concentration of the reactants. 2. 2. In the solutions resulting from the interaction of glutathione with maleimide and N-ethylmaleimide at 4·10 −6 M, different substances were found when the reaction was carried out in an unbuffered, neutralised medium and when it took place in phosphate buffer. 3. 3. The substances obtained in neutralised, unbuffered solutions have not been found at higher concentrations (4·10 −5 and 4·10 −4 M). 4. 4. The substances found in unbuffered, neutral solutions at 4·10 −6 M are the precursors of the substances obrained in phosphate buffer. 5. 5. The significance of these results for the interpretation of some of the observations, encountered with the unsaturated imides in tissue cultures of chick fibroblasts, is discussed. 6. 6. The different antimitotic activities of the unsaturated imide/glutathione mixture, dependent upon the concentration at which the compounds were brought to reaction before dilution, have found no satisfactory explanation, since the spectrophotometric investigation of the equilibrium mixtures, derived from the interaction at M/50 and M/1000, gave no conclusive results.

Mitosis of chick fibroblasts in the presence of unsaturated imides and sulphydryl compounds

1. 1. In tissue cultures of chick fibroblasts thiolacetic acid abolishes the antimitotic activity of maleimide and N-ethylmaleimide, but citraconimide remains active as a mitotic inhibitor in spite of the presence of thiolacetic acid. The compound obtained from the interaction of thiourea with N-ethylmaleimide is inactive. 2. 2. Glutathione gives different results when diluted after interaction with maleimide, N-ethylmaleimide and citraconomide at M/50 and at M/1000. The solutions obtained from M/50 have decreased antimitotic activity, compared with the antimitotic activity of the original imides, whilst the dilutions prepared from M/1000 are as active as the original imides.