Synthesis on N-Alkylated Maleimides

A two step synthesis of N-alkylated maleimides is presented. This method allows for the use of widely available starting materials and produces maleimides in high purity and yields. The maleimide precursors are of interest for potential thermo- and photo-setting polymerization processes.     

蒂巴茵衍生物的合成研究

The reaction of 7α-acetyl-6,14-endoethano-6,7,8,14-tetrahydrothebaine with 2-（thien-2-yl）ethylmagnesium bromide was investigated. The tertiary alcohol derivative 7α-[R-l-hydroxyl-l-methyl-3-（thien-2-yl）propyl]）-6,14- endoethano-6,7,8,14-tetrahydrothebaine （3） and a by-product 4 were isolated. The structure of 4 was elucidated by X-ray analysis. The Grignard reaction shows high degree of stereoselectivity according with Cram rule. The crystal structure of 4 indicates that dihydrofuran ring was opened to form a phenolic hydroxyl group and a three-membered ring structure. It maintains the main rigid structure of morphine and contains a C（6）-C（14） enthano bridge. The 1-hydroxyl-1-methyl-3-（thien-2-yl）propyl group at C（7） position adopted S-configuration.     

New Poly(4-Chloro)Maleimides. I. Synthesis and Characterization of Poly[Ether-Ester-(4-Chloro)Maleimides]

Abstract

New poly[N-(ester)-3-(ether)-4-(chloro)]maleimides were synthesized by the reaction of N-(4-chlorocarbonylphenyl)-3,4-dichloromaleimide (3) with various bisphenols such as hydroquinone (8a), 2,2-bis-(4-hydroxyphenyl)propane (8b), 4,4′ -(hexafluoroisopropylidene)diphenol (8c), and 2,5-bis(4-hydroxybenzylidene)cyclopentanone (8d). The structures of the resulted polymers were confirmed by IR and elemental analyses. A series of model compounds (4–7) was synthesized to facilitate confirmation of the structure of the polymers. The polymer containing hydroquinone units (9a) exhibited LC behavior in the melt, as observed by PLM measurements.     

Synthesis of Thione-Propiolic Acid Adducts

Abstract

Reaction of adamantane-2-thione with propiolic acid gave a novel type of cycloadducts, spiro[adamantane-2,2′-(1,3)-oxathiin]6-one, quantitatively. Thiocamphor and thiofenchone also reacted with propiolic acid to give the corresponding adducts stereoselectively. The observation of second-order reaction kinetics and highly stereoselective addition strongly support a cycloaddition mechanism for the thermal addition. The reaction of selenoketones with propiolic acid afforded a similar cylcoadduct. This is the first example of the reaction of monomeric thiones or selones with acetylenic acids.     

Facile and Stereoselective Synthesis of N-Substituted Benzotriazole with Baylis-Hillman Adducts

Benzotriazole derivatives are a class of useful intermediates in organic synthesis because of the easy introduction and elimination of the auxiliary benzotriazole. The syntheses and application of benzotriazole derivatives have been much developed, especi…     

Synthesis of N-Substituted Maleimides as Potential Antineoplastic Sulfhydryl Agents

For a purpose of antineoplastic screening, a series of sulfhydryl-binding agents, N-substituted maleimides was prepared. These compounds were obtained by dehydration of the corresponding maleamic acids under suitable conditions in which the formation of maleisoimide by-products was prevented, IR and UV spectra, as well as the elemental analyses confirmed the structural assignment of our products, A brief discussion on the preparation of N-(2,4-dinitrophenylamino)maleimide was also given.     

大黄酸-缬氨酸加合物的合成及初步抗肿瘤活性

以大黄酸为原料,经酯化、烷基化、水解及缩合等反应步骤合成了12个大黄酸-缬氨酸加合物.目标化合物经1H NMR,~(13)C NMR和HRMS进行了结构确证.以顺铂和阿霉素为阳性对照药,采用四甲基偶氮唑盐(MTT)法考察了目标化合物的体外抗肿瘤(Hela,MCF-7,HepG2,KB和HEK293T等5株细胞)活性.结果表明,化合物5l显示出较好的抗肿瘤活性,其IC50值在1.6~9.4μmol/L之间.作用机制研究结果表明,化合物5l能够与DNA发生较强的结合作用.     

Efficient Method for the Synthesis of Functionalized Basic Maleimides

A three‐step procedure involving Diels–Alder condensation of maleic anhydride with furane, formation of N‐substituted imide upon reaction with appropriate diamine, and a final retro Diels–Alder regeneration of the maleic carbon–carbon double bond is proposed for an unequivocal synthesis of N‐substituted basic maleimides. The novel method is characterized by mild reaction conditions, easy work‐up, high yields, and no need for additional catalysis.     

Synthesis and Transformations of NH-Sulfoximines

Recent years have seen a marked increase in the occurrence of sulfoximines in the chemical sciences, often presented as valuable motifs for medicinal chemistry. This has been prompted by both pioneering works taking sulfoximine containing compounds into clinical trials and the concurrent development of powerful synthetic methods. This review covers recent developments in the synthesis of sulfoximines concentrating on developments since 2015. This includes extensive developments in both S−N and S−C bond formations. Flow chemistry processes for sulfoximine synthesis are also covered. Finally, subsequent transformations of sulfoximines, particularly in N-functionalization are reviewed, including N−S, N−P, N−C bond forming processes and cyclization reactions.     

Mechanochemical Synthesis of Urea Adducts with Long Chain Alkyl Derivatives

The adducts of urea and solid alkyl derivatives can beobtained mechanochemically in good yields. Theproducts synthesized by grinding the solid reagentshave identical IR spectra and XRD powder patterns tothose obtained by crystallization from ethanolicsolutions.     

Intramolecular Tetrylene Lewis Adducts: Synthesis and Reactivity

A series of benzyl(diphenylphosphino) and o‐phenyl(diphenlyphosphino) substituted germylenes and plumbylenes were synthesized by nucleophilic substitution between the respective lithium reagent and tetrylene halide. The Lewis pairs were characterized by X‐ray crystallography and NMR spectroscopy. The reactivity of the tetrylenes was investigated with respect to azide addition. In the germylene case, the germaniumimide was formed as the kinetically controlled product, which rearranges upon heating to give the phosphinimide. The stannylene and plumbylene derivatives react with adamantylazide to give the azide adducts. 1‐Pentene reacts diastereoselectively with the phosphagermirane to give a cyclic addition product. Trimethysilylacetylene shows an addition with the benzylphosphino‐substituted germylene and plumbylene to give the cycloheteropentene molecules. The addition product between phenylacetylene and the four membered Ge‐P adduct shows after addition at room temperature a 1,4‐phenylmigration to give a cyclic phosphine. Alkylnitrene insertion into a Ge?C bond of the alkyne addition product of the phosphagermirane was found in reaction with adamantylazide.     

Lithium Diisopropylamide‐Mediated Carbolithiation Reactions of Vinylidenecyclopropanes and Further Transformations of the Adducts

Synthetic methods : Lithium diisopropylamide‐mediated highly selective carbolithiation reactions of vinylidenecyclopropanes are described and further transformations of these adducts were performed in the presence of Lewis or Brønsted acids (see scheme for sample reactions).

     

Quantum-Chemical Study of Adducts of Silicon Halides with Nitrogen-containing Donors: IV. Adducts with Pyridine

The structural and thermodynamic characteristics of SiX₄·Py and SiX₄·2Py adducts (X = H, F, Cl, Br) were calculated by ab initio and DFT methods (RHF and B3LYP). The resulting data were used to estimate for the first time the enthalpies of sublimation of trans-SiX₄·2Py complexes. The distortion energies of the donor and acceptor fragments and the energies of the Si-N bonds in the 1:1 and 1:2 halide complexes were calculated. The high distortion energy makes thermodynamically unfavorable equatorial monopyridine adducts with Si-N bond energies of 150-200 kJ/mol. In trans 1:2 complexes, pyridine acts as a weaker donor than ammonia with respect to silicon tetrahalides.     

Synthesis and Transformations of Norbornyl Acrylates

A simple and more environmentally friendly procedure than that traditionally used was developed for preparation of esters consisting in acrylic acid addition to bicyclo[2.2.1]hept-2-ene and its 5-alkyl derivatives. The acrylates obtained were subjected to hydrogenetion followed by hydrolysis of propionic acid esters. A number of new compounds was obtained; some among them possess a pleasant odor.     

Quantum-Chemical Study of the Adducts of Silicon Halides with Nitrogen-containing Donors: I. Adducts with Ammonia

Ab initio and DFT methods (RHF and B₃LYP) were used to calculate the structural and thermodynamic characteristics of adducts SiX₄·NH₃ and SiX₄·2NH₃ (X = H, F, Cl, Br). With the resulting data, the enthalpies and entropies of sublimation of SiF₄·2NH₃ were estimated for the first time. The effect of the nature of heteroatom X on the Si-N and Si-X bond lengths and atomic charges in the adducts and their dissociation enthalpies was analyzed. The hydride system was shown to differ from the halide systems, and the adducts with X = F have some peculiar features compared with those with X = Cl, Br. The Si-X bond is found to be sensitive to the charge redistribution produced by complex formation.     

蒂巴因与牛血清蛋白的相互作用

用荧光光谱和紫外-可见吸收光谱研究了中性条件下蒂巴因与牛血清白蛋白(BSA)结合反应的光谱行为,发现蒂巴因对BSA有较强的荧光猝灭作用,且蒂巴因的紫外吸收光谱和BSA的荧光发射光谱有一定程度的重叠,据此求得了其结合反应的结合位点数为1,结合常数为3.76×105,作用距离2.95 nm,并通过求算的基本热力学参数推测1分子的蒂巴因与1分子的蛋白质的212位色氨酸以静电作用力结合.     

Maleimides As a Building Block for the Synthesis of High Performance Polymers

Maleimides are gaining a great deal of attention in both scientific and industrial communities since they can be used in high performance macromolecular systems: thermosets with high temperature stability, self-healing systems, or in click chemistry reactions. After an introduction, this review reports in the first part the different routes to synthesize maleimides. In the second part, this review focuses on the use of maleimides in polymer synthesis, first through nucleophilic reactions, second via cycloaddition to yield remendable systems, and then via radical polymerization. Finally, the industrial availability of maleimides is discussed.     

Quantum-Chemical Study of Adducts of Silicon Halides with Nitrogen-Containing Donors: V. Adducts with 2,2'-Bipyridine and 1,10-Phenanthroline

Structural and thermodynamic characteristics of adducts of silicon tetrahalides with 2,2'-bipyridine and 1,10-phenanthroline were calculated by the DFT B3LYP method. The enthalpies of sublimation of SiCl₄·2,2'-bipyridine, reconstruction energies for donor and acceptor fragments, and energies of Si-N bonds in the complexes under consideration were estimated using the data obtained. These characteristics were compared with similar data for pyridine complexes. The chelate effect on the energy of Si-N bonds upon replacement of pyridine by 2,2'-bipyridine and 1,10-phenanthroline was discussed. The significant reconstruction of the bidentate donor upon the complex formation levels off the chelate effect.