Preparation,Properties and Reactions of Polychloroamine Derivatives

Highly chlorinated amine derivatives can be prepared by the high-temperature chlorination of amines and amine derivatives. Essential for the success of this reaction is an adequate temperature control suited to the constitution of the amines. In many cases the chlorination products achieve stability by cleavage reactions with formation of the imidic acid chloride or isocyanide dichloride grouping. Cyclic compounds are formed under special conditions. The chlorination process described can be used to obtain e.g. polychloroaryl and polychloroalkyl isocyanide dichlorides, polychloroaryl and polychloroalkyl imidic acid chlorides, and polychloroheterocyclic compounds.     

Preparation,Reactions, and NMR Studies of 4-Methyl-4-Phospha-Tetracyclo [3.3.0.02,8.03,8] Octane 4-Oxide and Derivatives

Abstract

The title compound which we¹ and others² have previously synthesized has now been extensively investigated. The tetracyclic phosphonium chloride 1 was prepared by treatment of norbornadiene with CH₃PCl₂ at 65–80°C for one week. Treatment of 1 with AICl₃/CH₂CI₂ gave 2. Direct or “Inverse” addition at water to 2 dictated the stereochemistry of the oxide 3. Stereoassignments of 3 were made based on lanthanide shift ?¹H and ¹³C nmr studies studies. Extensive 2-D nmr studies (HETCOR, COSY) and triple irradiation experiments enabled chemical shift and coupling constant assignments.     

Synthesis and Reactions of Some 1-Thiapyran-4-One Derivatives

The preparation of some 3,5-diarylidene-1-thipyran-4-one derivatives (Ia-e) was described. Oxidation of Ia, b and Ie with hydrogen peroxide gave the corresponding dioxides (IIa-c). Reaction of the 1-thiapyran-4-one derivatives with bromine, Grignard reagents, and amines were studied. Structural assignments are supported by spectral (UV, IR, and ¹HNMR) data.     

Reactions of 2-Deoxy-4, 5-O-Isopropylidene-D-Erythro- and D-Threo-Pent-1-Enose Derivatives

ABSTRACT

The reactivity of the title compounds has been studied toward different nucleophiles and electrophiles. Unlike other ketene dithioacetals, compounds 3-5 did not add nucleophiles to the double bond. Instead, in the presence of Lewis acids they underwent substitution reaction at position 3. If the nucleophile was not strong enough, formation of 6 and 7 were observed. With 2,3,4,6-tetra-O-acetyl-1-thio-β-D-glucopyranose (18), a 3:1 mixture of 11 and 12 was formed from 4. These observations may be interpreted in terms of easy formation of the allylic carbocation I which gives diastereomers with nucleophiles. However, this allylic ether-like behaviour was ruled out by the fact that compounds 9 and 10 did not undergo [2,3] sigmatropic rearrangement with lithium diisopropylamide. With N-bromosuccinimide compound 3 gave the 2-bromo derivative 8. Compounds 3 and 8 resisted common mercury salt assisted demercaptalization procedures.     

Preparation and Reactions of Permethylated Cyclooligosilane Alkali Metal Derivatives

Abstract

A simple way for the synthesis of potassium undecametylcyclohexasilane is described and discussed.     

合成二茂钛衍生物的超分子界面催化反应研究

设计了一种超分子催化合成二茂钛衍生物的反应模型,并通过水溶性β-环糊精聚合物(WS-β-CDP)催化两相法合成二茂钛衍生物的反应得到了证实.利用荧光光谱和电子吸收光谱对反应过程进行了在线监测,发现WS-β-CDP可作为超分子微反应器,优先与配体可逆地形成超分子配合物,将配体激活,并在两相界面与二氯二茂钛发生反应,形成目标产物;之后,产物脱离空腔留在了有机相,而下一个配体则进入反应器继续反应.同时发现,体系中WS-β-CDP的存在对提高二茂钛物种的稳定性非常有利,并使其安全pH值提高至10.60.     

Stereochemistry of Asymmetric Kabachnik-Fields and Pudovik Reactions

Abstract

Kabachnik-Fields and Pudovik reactions were studied with the use of chiral initial reagents. In all cases the products of these reactions represent a mixture of diastereomers.     

Reactions with Stilbenes and Related Derivatives. Part I. Reactions of 1, 2-Dihalogeno-1, 2-bis-(4-methoxyphenyl)ethanes with Alcohols

The reaction of 1, 2-dibromo-1, 2-bis(4-methoxyphenyl)ethane with alcohols was associated with rearrangement to give the corresponding bis(4-methoxyphenyl)acetals. In boiling ethylene glycol 4,4′-dimethoxy-deoxybenzoin was also obtained due to an aldehyde-ketone rearrangement. 4,4′-Dimethoxybenzophenone was also formed being apparently derived from the acetals. The mechanism of formation of the acetals has been discussed.     

1,5-苯并硫氮杂氯代β-内酰胺衍生物的合成、光谱及立体化学

苯并硫氮杂是一类具有重要生理活性的七元杂环化合物，近年来，通过亚胺双键（ＣＮ）的环加成反应向此类化合物分子中引入新的环系引起了人们的关注［１～４］．这项工作对于合成新的杂类化合物从而筛选出具有特殊生理活性的物质有着重要意义．本文通过１，５－苯并...     

Synthesis and Stereochemistry of C-Functional Derivatives of Phosphabicyclodecane

Abstract

Methods for synthesis of new phosphabicyclodecanes with substitution in a heterocycle were worked out. Configurations of individual stereoisomers of P (III) phosphabicyclodecanones, their oxides, sulfides and selenides were established by ¹H, ¹³C, ³¹P NMR spectroscopy and X-ray analysis. The results show that electron-acceptor groups (C=O, P=X) enhance mobility of hydrogen atoms in the heterocycle which leads to the increasing ability of phosphabicyclodecanones for deuteration (in a-position to C4, P=X), participation in aminomethylation reaction and to the capability to react with electrophiles. The isomerization of 5-oxo- and 5-hydroxyderivatives of P (IV) phosphahicyclodecane in presence of acid and basic catalysts was detected and studied. The mechanism of ketoenolic and thiophosphoryl-merkaptoilide (selenophosphoryl-selenoloilide) ternary prototropic tautomerism is proposed. By varying the temperature and the nature of the solvent and catalyst, it is possible to alter the direction and depth of isomeric transformations. As the result of the studies of Stereochemical directivity of reactions of nucleophile addition to double C=O and C=C bonds and of electrophile substitution in phosphabicyclodecanones, the functioning possibilities of such compounds were determined. Polyfunctional derivatives of phosphabicyclodecane, which are of interest for fine organic synthesis of new organophosphorus compounds were obtained.     

Stereochemistry of the Reactions of Cyclic Ketones with Lithium Aluminum Hydride and Methyllithium. IV. The Stereochemistry of the Reactions in 2,2-Dimethyl-4-t-Butylcyclohexanone Systems

Previous publication showed that the stereochemistry of lithium aluminum hydride reduction of cyclic ketones can be evaluated by the use of an empirical equation, . This paper reports further test of this relationship in the new system of 2,2-dimethyl-4-t-butyl-cyclohexanone. Lithium aluminum hydride reduction of this ketone yields 95.6% trans-alcohol (lit., 95.9%) corresponding to D?(D?G*)_H of 1.67 Kcal/mol. With methyllithium, the ketone formed 77.5% of trans-alcohol (D?(D?G*)_D?fs = 0.67 Kcal/mol). These data give a calculated D?G* = 0.74 Kcal/mol which agrees well with the literature value of 0.87 or 0.28 Kcal/mol. Structural assignments of 2,2-dimethyl-4-t-butylyclohexanone, 1,2,2-trimethyl-cis- and trans-4-t-butylcyclohexanols by pmr spectroscopic method are also given.     

Synthesis and Stereochemistry of New N-Substituted Cytisine Derivatives

A series of new N-substituted cytisine derivatives was synthesized. The ¹ H and ¹³ C NMR spectra of certain compounds exhibit a doubled set of signals. This is explained by formation of diastereomeric pairs in compounds containing an asymmetric center in the substituents. The signal splitting in -COHC=CHCO ₂ H and HC=O (formyl) derivatives is explained by the existence of Z and E invertomers. Their stereochemical features are discussed. Amide conjugation is confirmed by temperature experiments.     

1，3，4，6－四硫代戊搭烯－2，5－二酮制备含硫取代基的四硫富瓦烯的研究

以１，３，４，６－四硫代戊搭烯－２，５－二酮为原料，经偶联、醇解、烃化或醇解、烃化、偶联等步骤，制得四甲硫基四硫富瓦烯、四乙硫基四硫富瓦烃、二喹喔啉硫醚、４－甲硫基－５－甲氧甲酰硫基－１，３－二硫环戊烯－２－酮、四甲硫基乙烯和４，４＇－二甲硫基－５，５＇－二甲氧甲酰硫基四硫富瓦烯及它的异构体混合物．提出了１，３，４，６－四硫代戊搭烯－２，５－二酮醇解机理．讨论了未得到某些预期产物的原因．报道了３种四硫富瓦烯衍生物的循环伏安图及电化学性质．     

Stereochemistry of Macrocyclization of cis-4-Cyclohexene-1,2-dicarboxylic Acid with Dihalogen Derivatives

Stereochemistry of [2+2]- and [1+1]-macrocylization of cis-4-cyclohexene-1,2-dicarboxylic acid with 1,2-dibromoethane, 1,3-dichloro-2-propanol, and 1,5-dichloro-3-oxapentane was studied. The reaction of cis-4-cyclohexene-1,2-dicarboxylic acid with 1,2-dibromoethane according to the [2+2]-cyclization scheme gave a mixture of stereoisomeric macroheterocycles with cis,syn,cis- and cis,anti,cis-junction of the polyether and cyclohexene rings. In the reaction of cis-4-cyclohexene-1,2-dicarboxylic acid with 1,5-dichloro-3-oxapentane, a mixture of crown compounds with cis,anti,cis- and cis-junction of the polyether and cyclohexene rings was obtained. The structure of the products was established on the basis of their chemical transformations and spectral data.     

Synthesis of 4-Phenoxytetrahydro-1,3,4λ5-thiazaphosphol-2-one 4-Sulfide

Russian Journal of General Chemistry -     

Synthesis and Stereochemistry of Some New 1,3-Oxathiane Derivatives

Summary. The synthesis and stereochemistry of some new 2,5-substituted 1,3-oxathiane derivatives are reported. The anancomeric or flexible structure of the derivatives and some peculiar cases of prochirality are revealed by NMR investigations.