Use of microwave irradiation for sugar and nucleoside phosphonates synthesis

Sugar and nucleoside phosphonates have been prepared using a microwave-assisted reaction. The comparison of thermal and microwave experimental conditions of the Michaelis-Arbuzov reaction is reported.     

3-取代-3-苯基-1-茚酮类化合物的合成

以3-苯基-1-茚酮（1）为原料,THF为溶剂,二异丙基氨基锂（LDA）为碱,与碘代烷（RI）经亲核取代反应合成了4个3-取代-3-苯基-1-茚酮类化合物（3a~3d),其中3b~3d为新化合物,其结构经¹H NMR, ¹³C NMR 和EI-GC-MS表征。在最佳反应条件［1 1.0 eq., LDA/RI=2.1/1.5（当量比）,于0 ℃~rt反应5 h］下,3a~3d收率为70％～80％。     

基于核苷类化合物HILIC-ESI-TOF/MS分析的海洋动物药指纹图谱方法

探讨了核苷类化合物指纹图谱用于不同海洋动物药真伪鉴别的可行性, 为贵重动物药的鉴别提供了一种新方法. 采用亲水色谱-电喷雾飞行时间质谱(HILIC-ESI-TOF/MS)对不同海洋动物药中的16种核苷类化合物进行分析, 构建了基于16种核苷类化合物的特征指纹图谱, 结合相似度分析和聚类分析, 用于不同海洋动物药的鉴别. 结果表明, 基于核苷类化合物HILIC-ESI-TOF/MS分析的指纹图谱能反映不同海洋动物药各自的固有特征, 结合相似度分析和聚类分析可实现对不同海洋动物药的正确区分. 说明核苷类化合物指纹图谱有望成为动物药鉴别的新方法.     

Highly regio- and diastereoselective halohydroxylation of olefins: a facile synthesis of vicinal halohydrins

An efficient method for the synthesis of vicinal chlorohydrin or bromohydrin derivatives has been developed on the basis of direct halohydroxylation of various olefins with electrondonating or withdrawing substituent. The reactions were carried out under mild conditions in the presence of N-tosyl-l-threonine (NTsLT) as an acidic additive using chloramine T trihydrate, 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) or N-bromoacetamide (AcNHBr) as the halogen source, respectively, affording the corresponding vicinal halohydrins in good to high yields with excellent regio- and stereoselectivities.     

Modular and stereoselective formal synthesis of MeBmt, an unusual amino acid constituent of cyclosporin A

A convergent, flexible and stereoselective formal synthesis of MeBmt, the nonproteinogenic amino acid constituent of cyclosporin A is disclosed. The sulfinyl moiety has been exploited as the internal nucleophile to stereo- and regioselectively functionalize an allylic carbamate.     

Bromohydrin reactions of Grieco’s bicyclic lactone

The bromohydrin reaction in Grieco’s bicyclic lactone 1 was reinvestigated. Two regioisomeric bromohydrins were obtained (2 and 8), and their configurations were unambiguously determined by X-ray diffraction analyses.     

A highly regio- and chemoselective synthesis of vicinal bromohydrins by ring opening of terminal epoxides with dibromoborane-dimethyl sulfide

Dibromoborane-dimethyl sulfide (BHBr₂-SMe₂) displays high degrees of chemo- and regioselectivity during the brominative cleavage of the epoxy group into vicinal bromohydrins in the presence of alkene, alkyne, allene, ether, acetal and acetonide, besides its hydroborating ability. Several reducible functional groups, such as chloride, aldehyde, ketone, azide, ester, nitrile and tert-amino ester, have been successfully accommodated during the epoxide opening process.     

A New Synthetic Approach to Elvucitabine

A new synthetic approach to elvucitabine started from L-xylose via the reactions of 10 steps in an overall yield of 20% was developed. The key steps included trimethylsilyl trifluoromethanesulfonate(TMSOTf)-mediated stereocontrolled β-glycosidation and exquisite choice of chloroacetyl group for the protection of hydroxyl groups as well as the corresponding deprotection under notably mild conditions. The structure of elvucitabine, in particular, the stereochemistry thereof, was unambiguously determined by comparison of the physical properties, such as ¹H NMR data and the specific rotation, of the synthesized sample with those reported.     

Stereoselective Borane Reduction of Acetophenone using 1,3,2-Oxazaborolidine Derived from (R)-4-(Diphenylhydroxymethyl)-1,3-Thiazolidine

A new chiral 1, 3, 2-oxazaborolidine derived from (R)-4-(diphenylhydroxymethyl)-l, 3-thiazolidine has been synthesized and its efficiency in the asymmetric reduction of acetophenone by borane has been investigated. It gives (R)-l-phenylethanol with high enantiomeric excess     

New Hydrazinium Azide Compounds

The synthesis and characterization of several azide salts of organic hydrazinium derivatives is reported. The crystal structures of N‐amino‐1‐azoniacycloheptane azide, morpholinium azide, N,N‐dibenzylhydrazine and phenylhydrazinium azide phenylhydrazinate were determined. The thermal, shock and friction sensitivity of these compounds was investigated. For several compounds the products formed in the explosive decomposition were determined.     

New Syntheses of Diazo Compounds

Diazo compounds (R¹R²C?N₂) are known as versatile and useful substrates for an array of chemical transformations and, therefore, diazo chemistry is still far from losing anything of its long‐standing fascination. In addition to many studies on the subsequent chemistry of the diazo group, the inventory of methods for the preparation of diazo compounds is continuously supplemented by new methods and novel variations of established procedures. Several of these synthetic approaches take into account the lability and remarkable chemical reactivity of certain classes of diazo compounds, and environmentally more benign procedures also continue to be developed.     

人工神经网络法预测核苷及核酸碱基的疏水分配系数

用人工神经网络方法预测核苷及核酸碱基一类化合物的ｌｇＰ值,预测精度显著优于ＢｌｇＰ法和ＡｌｇＰ法,根据预测结果讨论了分子内氢健及分子构象柔顺性对这类化合物疏水性的影响。     

Synthesis of Carboxylactones and New Heterocyclic Compounds

The Michael reaction of 2‐ethoxycarbonyl‐4‐alkoxymethylbutanolides with methyl acrylate affords esterolactones in high yields. Alkaline hydrolysis of the latter resulted in carboxylactones that were transformed into ethyl α‐bromolactonoesters. The reactions of the latter with thiourea and arylthioureas result in heterocyclic compounds of an original structure joint with a butanolide ring.     

几种新的四苯(基)苯基有机硅化合物的研究

本工作以双乙烯基四甲基二硅氧烷、乙烯基甲基二氯硅烷、乙烯基七甲基环四硅氧烷分别与四苯基环戊二烯酮通过Diels-Alder反应合成了相应的四种四苯(基)苯基有机硅化合物(Ⅰ-Ⅳ)。并由化合物Ⅲ又制成了三种化合物Ⅴ一Ⅶ。对这些新化合物的组成、结构作了相应的分析、测试和鉴定。还对有些Diels-Alder反应做了改进,从封管反应改为常压反应后,效果更佳。     

Synthesis and Reactivity of New Organophosphorus Compounds

Abstract

Synthesis of functionally substituted organophosphorus compounds on the basis of reactions of the tri-n-butylphosphine/carbon disulfide, tri-n-butylphosphine/phenylisothiocyanate, tris(dimethylamino)phosphine/phenylisothiocyanate adducts with a wide range of different dipolarophiles are reported. The development of application of S-Li tri-n-butylphosphonio-dithioformiate derivatives to the synthesis of new types of organophosphorus compounds are reported.     

Synthesis of Some New Fused/Spiroheterocyclic Compounds Incorporating Quinone Compounds

A series of fused and spiro pyrazolones, isoxazolines, pyrimidines, β‐lactams, and thiazolidinones incorporating 4‐amino‐2‐methyl‐5,10‐dioxo‐1,5,10,11‐tetrahydrobenz[g]quinoline 3‐carbonitrile 1 and 4‐amino‐2‐methyl‐5,6,11‐trioxo‐1,4,4a,5,6,11,12,12a‐octahydro‐1,12‐diazanaphthacene 3‐carbonitrile 2. 7,8a‐c, 15,16a‐c, 19,20a‐d, 21,22a‐d , have been synthesised by cyclocondensation addition reaction and cycloaddition reaction of hydrazines, hydroxylamine, urea, thiourea, monochloroacetyl chloride and mercaptoacetic acid with the synthesised 15,16a‐c and 17,18a‐c .     

新型吡唑联吡咯类杂环化合物的合成及杀菌活性

为寻找具有更高生物活性、更环保的新农药杀菌剂,基于杀菌剂氟咯菌腈设计并合成了10个新型吡唑联吡咯类杂环化合物,以吡唑环代替氟咯菌腈上原有的苯环,以期提高其杀菌活性.采用1H NMR,FTIR,单晶X射线衍射、元素分析和熔点测定等测试手段对目标化合物及其中间体的结构进行了表征与确认,并通过挥发法培养得到了6个目标化合物的单晶.还对其中6个化合物进行了生物活性测试,测试结果表明各化合物对水稻纹枯病、黄瓜灰霉病、黄瓜霜霉病均表现出一定的抑菌效果,可作为先导化合物对其结构进行深入的研究,为新农药杀菌剂的开发提供了理论支持.     

Synthesis and Antitussive Effect of New Hydantoin Compounds

A series of new hydantoin compounds was synthesized with 3-bromo phenylacetic acid and 3,4-dimethylbromobenzene as starting material, 7-bromo-2-tetralone and 2-bromo-5,6,8,9-tetrahydro-7-benzocyclo- heptenone as intermediate and Ullmann reaction, Suzuki reaction and Bucherer-Berg's reaction as key steps. The structures of the key intermediate and target compounds were confirmed by ¹H NMR, ¹³C NMR, IR and MS. Bioactivity research showed that target compounds 6a, 6c, 6d, 6e and 15i had significant antitussive effect on the ammonia-induced cough of mice.