吡啶酰胺在Cd(Ⅱ)存在下的醇解反应及结构表征

X-射线晶体结构分析表明,在90℃的水热条件下,N-(8-喹啉基)吡啶-3-酰胺在Cd²⁺的存在下发生醇解。醇解产物为8-氨基喹啉(HL₁)和吡啶-3-羧乙酯(HL₂),它们与Cd(Ⅱ)配位形成四方锥型化合物。该配合物为单斜晶系,空间群P2₁/c,a=18.1089(1)?,b=8.9986(1)?,c=19.3070(2)?,β=113.085(1     

Synthesis and properties of novel dialkylaminocarbenium salts

Novel dialkylaminocarbenium salts with metallocomplex counter ions were prepared by the reaction of phosgene with either DMF or tetramethylurea in the presence of metal chlorides. Reactions of organosilicon amides with phosgene gave corresponding carbenium salts, while organosilicon ureas yielded aminoiminocarbenium salts. Dialkylaminochlorocarbenium salts were reduced with hydrosilanes to give dialkylaminocarbenium, salts and can be easily hydrolyzed to afford either amides or ureas. Pathways of the reaction with water and alcohols depend on the nature of reagent and the reaction conditions. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1035–1040, May 1997.     

Alcoholysis of hydridesilanes to give silyl ethers catalyzed by rhodacarboranes closo-3,3-(Ph3P)2-3-H-3,1,2-RhC2B9H11 and closo-3,3-(η2,η3-C7H7CH2)-3,1,2-RhC2B9H11

Rhodacarboranes closo-3,3-(Ph₃P)₂-3-H-3,1,2-RhC₂B₉H₁₁ and closo-(²,³-C₇H₇CH₂)-3,1,2-RhC₂B₉H₁₁ are catalysts for the alcoholysis of hydridesilanes. Closo-3,3-(²,³-C₇H₇CH₂)-3,1,2-RhC₂B₉H₁₁ displays greater activity than closo-3,3-(Ph₃P)₂-3-H-3,1,2-RhC₂B₉H₁₁ though both rhodacarboranes catalyze the alcoholysis of hydridesilanes more efficiently than (Ph₃P)₃RhCl.A. N. Nesmeyanov Institute of Organometallic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 7, pp. 1657–1660, July, 1992.     

Application of an adiabatic precision calorimeter in the field of organic reactions

Adiabatic calorimetry is a suitable method for investigations of reactions because the generated heat remains completely in the reactor. For the investigation of organic reactions, the adiabatic precision calorimeter ACTRON 5 is used. The alcoholyses of phenyl isocyanate and 1,2-butyleneoxide were investigated. The temperature-time course was estimated by means of the nonlinear program TA-kin. Inclusion of the concentration-time course in the estimation procedure led to an increase in the reliability of the parameters. Probes were taken during isoperibolic measurements and were analysed by means of HPLC.     

(±)-金锦香酸二甲酯甲醚的合成

本文以呋喃甲酸甲酯为原料, 经羟烷基化反应, 醇解反应和O-甲基化反应合成(±)-金锦香酸二甲酯甲醚。同时, 还发现了制备2-乙烯基呋喃衍生物的新方法。     

PHOSPHORUS-CONTAINING AMINOCARBOXYLIC ACIDS. COMMUNICATION IV.1 A CONVENIENT METHOD OF PHOSPHONIC ACIDS SYNTHESIS

Abstract

The communication is concerned with the synthesis of phosphonic aminocarboxylic acids by phosphorylation of diethyl ω-halogen alkyl acetamidomalonates with tris(trimethylsilyl) phosphite, followed by alcoholysis and acid hydrolysis of the resulting intermediate esters.     

Catalytic Activity of Amines Hydrochlorides,Intramolecular Catalysis and Stereoselectivity of Phosphorylation of Hydroxylcontaining Nucleophiles with P(III)-N-Ethylanilines

Abstract

The effect of acid-base properties of amines hydrochlorides (AH) on their catalytic activity in methanolysis of P(III)-N-ethylaniline has been studied. The analysis of Bronsted correlation equation was indicative of general acid catalysis and it was thus confirmed, that general regularities had place during alcoholysis of P(III)-amines under catalysis with AH. In addition, the increasing of alcohol polarity leads to the increasing of proton transfer degree (α) from acid catalysts to phospho(III)amine substrate and to the increasing of the positive charge at the phosphorus in the transition state. Besides, the comparison of α values indicates that in more polar methanol (in comparison with tbutanol) the catalysis is more sensitive to the acidity change of used catalysts.     

Synthesis,isolation and characterization of methyl levulinate from cellulose catalyzed by extremely low concentration acid

A direct synthesis of methyl levulinate from cellulose alcoholysis in methanol medium under mild condition (180–210 °C) catalyzed by extremely low concentration sulfuric acid (≤0.01 mol/L) and the product isolation were developed in this study. Effects of different process variables towards the catalytic performance were performed as a function of reaction time. The results indicated that sulfuric acid concentration, temperature and initial cellulose concentration had significant effects on the synthesis of methyl levulinate. An optimized yield of around 50% was achieved at 210 °C for 120 min with sulfuric acid concentration of 0.01 mol/L and initial cellulose concentration below 100 g/L. The resulting product mixture was isolated by a distillation technique that combines an atmospheric distillation with a vacuum distillation where n-dodecane was added to help distill the heavy fraction. The light fraction including mainly methanol could be reused as the reaction medium without any substantial change in the yield of methyl levulinate. The chemical composition and structural of lower heavy fraction were characterized by GC/MS, FTIR, ¹H-NMR and ¹³C-NMR techniques. Methyl levulinate was found to be a major ingredient of lower heavy fraction with the content over 96%. This pathway is efficient, environmentally benign and economical for the production of pure levulinate esters from cellulose.     

Applications of Dithioacetals in Ester Synthesis

The α-oxoketene dithioacetals are simple synthetic intermediates widely utilized and implicated for the synthesis of a variety of heterocyclic compounds other than alicyclic and aromatic compounds. They act as 1,3-electrophilic three-carbon synthons. The α-oxoketene dithioacetal of pyrazolone derivatives can be efficiently converted through a base-catalyzed alcoholysis into the corresponding ester in a single one-step reaction with good yield of pure products. In this article, we summarize recent direct conversion of α-oxoketene dithioacetals to highly desirable esters. The overall process is an example of intramolecular rearrangement of bonds. Characterization and identification of all synthesized compounds were assigned through ¹H NMR and mass spectroscopy.     

Selective Synthesis of β‐Hydroxy Nitroethanol Ethers by Alcoholysis of Oxiranes

β‐Hydroxy nitroethanol ethers are prepared by selective alcoholysis of oxiranes. The best results are obtained using a clay (monmorillonite K10) or a π‐acid (TCNE) as the catalyst.