Facile oxidative conversion of alcohols to esters using molecular iodine

A simple, efficient, and high-yield procedure for the oxidative conversion of alcohols to various types of esters and ketones, with molecular iodine and potassium carbonate was successfully carried out.     

Stereoselective synthesis of (−)-microcarpalide

A highly convergent and efficient synthesis of (−)-microcarpalide, a 10-membered lactone displaying remarkable microfilament disrupting activity is described. Ring-closing metathesis and Sharpless asymmetric dihydroxylations are the key steps. Our strategy highlights the application of novel hydroxy lactone precursors for the stereoselective synthesis of (−)-microcarpalide.     

配糖蛋白B—阳离子丙烯酸树脂微胶囊的性能研究

本文研究了配糖蛋白B-阳离子丙烯酸树脂微胶囊的形态、粒径及粒径分布,并在模拟胃液的酸性缓冲液中进行了微胶囊的溶解释放试验。结果表明该微胶囊能溶于人体的胃液中,可配制适合儿童口服的混悬剂。     

Direct organocatalytic in situ generation of novel push-pull dienamines: application in tandem Claisen-Schmidt/iso-aromatization reactions

A new, green, regioselective, one-step, tandem reaction of an aldehyde possessing a non-enolizable carbonyl function with a highly substituted cyclohex-2-enone, under amine catalysis afforded highly substituted phenols or 2-arylidenecyclohexanones, respectively. The yields and regioselectivities were good. Evidence for a pathway involving formation of novel push-pull dienamines is presented along with examples demonstrating the amenability of the process to combinatorial chemistry.     

Bond interchange reactions in functionalized triglyceride oil/poly(ethylene terephthalate) compositions

Naturally functionalized triglyceride oils are renewable resources which contain reactive chemical groups, hydroxyl in the case of castor oil, and epoxide in the case of vernonia oil. In this article, the reaction of these groups, and the ester linkages between the glycerol and acid residue portions of the oil molecule with poly(ethylene terephthalate) (PET) is investigated through a variety of means. Multiple reactions are possible in the triglyceride–PET system, some of which form a copolymer that increases miscibility, and if allowed to continue, forms a completely random copolymer mixture. Among the numerous reactions possible, PET–ester exchange with the hydroxyl or epoxide functionality of the triglyceride oils is found to be the most significant, and the effects of these and other reactions are observed and structural implications discussed. © 1993 John Wiley & Sons, Inc.     

含羟基芳基或氨基芳基的磷酰胺酯衍生物的合成

采用均相反应的方法合成了6个含羟基芳基或氨基芳基的磷酰胺酯衍生物:[(ClCH_2CH_2)_2NP(O)(OPh)(XArY)](X:O,NH;Y:m或p-OH或NH_2).用元素分析、红外光谱、氢核磁共振谱及质谱证实了它们的组成及结构.     

Non-catalytic Addition of 1,2,4-Triazole to Nucleophilic and Electrophilic Alkenes

Non-catalytic addition of 1,2,4-triazole to vinyl ethers and esters occurs on heating (65-175°C, 4-20 h) to give Markovnikov adducts (yield 30-100%). Electron-deficient alkenes (acrylonitrile, acrylic acid, 4-phenyl-3-buten-2-one) react with 1,2,4-triazole (78-190°C, 4-20 h) to give anti-Markovnikov adducts in yields of 45-83%.     

Recyclization of pyrimidinium salts into 1,2,4-triazole derivatives

The interaction of the iodomethylates of pyrimidinyl-2-acetic acid derivatives with monosubstituted hydrazines, in addition to the products of a Kost-Sagitullin rearrangement, leads also to N-substituted triazoles. The structure of the triazoles was demonstrated by NOESY NMR experiments. The structure of the reaction products was determined on the basis of the response observed in the spectra between the methyl group protons of the triazole ring and the spatially close proton of the substituent in position 1 and a conclusion was drawn on the direction of the primary attack of nucleophile in the recyclization process of the pyrimidinium salts into a 1,2,4-triazole. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1175–1179, August, 2007.     

Are the pyrazolines formed from the reaction of [60]fullerene with alkyl diazoacetates unstable?

[60]Fullerene-fused pyrazolines 1 were prepared by the reaction of C₆₀ with alky diazoacetates under the solid-state high-speed vibration milling conditions as well as in toluene solution. Pyrazolines 1 were stable in refluxing toluene and its thermolysis process in 1,2-dichlorobenzene was investigated, the decomposition rates and activation energies of pyrazolines 1 were obtained. The current work demonstrated that the liquid-phase reaction of C₆₀ with alkyl diazoacetates undergoes via 1,3-dipolar cycloaddition pathway at room temperature, or proceeds via carbene mechanism at a temperature of refluxing toluene, thus clarifies the previous ambiguity of its reaction mechanism.     

Synthesis and characterization of new epoxy and cyanate ester resins

New epoxide and cyanate ester resins with an aromatic ester backbone namely 1,3-[di-(4-glycidyloxy diphenyl-2,2^′-propane)]-isophthalate (DGDPI) and 1,4-[di-(4-cyanato diphenyl-2,2^′-propane)]-terephthalate (DCDPT) were synthesized and the intermediates were characterized by IR, 1H-/¹³C-NMR spectroscopic methods. The cured products from DGDPI and DHDPI exhibited higher T_g compared with standard epoxy system. The increase in the T_g may be due to the cyanate ester and rigid aromatic backbones present in the curing system.