β-芳基烯酰胺化合物的新合成方法

本文报道了一条简便合成烯酰胺类化合物的方法.在酸酐或酰氯的存在下,通过钛锌试剂还原硝基芳基乙烯类化合物一步生成芳基烯酰胺类化合物,并利用此法实现了天然产物Alatamide的合成.     

A Convenient New Method for the Preparation of Diaryl Diselenide1

Diaryliodonium salts react with sodium O, O- diethyl phosphoroselenoate in ethanol-IMF at 70–80° C then hydrolyzed in basic medium and oxidized at room temperature to afford symmetric diaryl diselenides in better yields.     

新方法合成4-氰基-1-茚酮

以邻氰基氯苄和丙二酸二乙酯为原料,经缩合、碱水解、脱羧和Friedel-Crafts酰化反应合成了4-氰基-1-茚酮,总收率32.1%,其结构经1H NMR和13C NMR确证。     

新型1-芳氧基-4-氯酞嗪的合成及除草活性

新型1-芳氧基-4-氯酞嗪的合成及除草活性;芳氧基氯酞嗪;合成;除草活性     

New Efficient Synthesis of Methyl Trans-2-Aryl (or Hetaryl)-1-Benzamidocyclopropancarboxylates

Methyl trans-2-aryl(or hetaryl)-1-benzamidocyclopropancarboxylates can be easily obtained by thermal decomposition of trans-4-aryl(or hetaryl)-3-benzamido-3-carbomethoxy-Δ¹-pyrazolines synthesized by 1,3-dipolar cycloaddition of diazomethane with methyl E-3-aryl(or hetaryl)-2-benzamido-2-propenoates.     

Electrochemical Reduction of 1,4-Disubstituted Phthalazines

Electrochemical reduction in dimethylformamide of unsymmetrical 1-Cl-4-X-phthalazines and symmetrical 1,4-X₂-phthalazines (X = Cl, PhO, MeO, EtO, i-PrO) was studied by voltammetry and electrolysis-ESR. The electron trasfer on 1,4-dichlorophthalazine and unsymmetrical 1-Cl-4-X-phthalazines induces anionoid elimination of Cl and X, pyridazine ring cleavage, and phthalonitrile formation. In this previously unknown process the transfer of two electrons induces cleavage of three bonds and formation of two new bonds. The reduction of 1,4-dialkoxy(diaryloxy)phthalazines involves formation of stable radical anions which undergo no heteroring cleavage. Possible mechanisms of the processes studied were discussed. It was assumed that the same mechanism with pyridazine ring cleavage may be realized with other phthalazine derivatives and heteroannelated pyridazines containing readily leaving nucleofuge groups to nitrogens.     

1-取代异喹啉合成新方法的研究

在氯代甲酸苄酯活化下, 利用格氏试剂对异喹啉进行亲核加成, 得到1-取代-2-苄氧羰基-1,2-二氢异喹啉, 然后在Pd/C/HCO₂NH₄体系中进行芳构化, 得到1-取代异喹啉. 采用同样的方法, 一些2-取代的喹啉也能被合成.     

A New Method for the Synthesis of gem-Dihydroperoxides

The tungstic acid-catalyzed reaction of ketals with hydrogen peroxide provides a convenient and efficient method for preparing gem-dihydroperoxides.     

A New Method for the Synthesis of Oligo-peptides

It was discovered that polypeptides were formed by self-assembly of N,O-bis(trimethylsilyl)amino acids with the assistance of O-phenylene phosphorochloridate.^[1] There were three steps involved in the self organization reactions, the activation of amino acid, the elongation of peptide chain and the termination of the chain reaction,among which the activation of amino acid -the formation of imino (alkyl)acetoxyphosphoranes was the key step. The formation process of the penta-coordinated phosphorus intermediates was showed in scheme 1.^[2,3,4] Through further studies of the mechanism of self-assembly reaction, it was found that carbonyl groups of the intermediates attacked by the neuclophilic groups were direct reson of the formation of peptides. However, the peptides in the solution were very difficult to be separated and analyzed.     

合成光学活性1,1＇-联-2-萘酚的新方法

利用(一)-1,1′-联-2-萘酚[(—)-1]与(+)-1-苯基-2-丙胺[(+)-2]·Cu(Ⅱ)络合物及(+)-1,1′-联-2-萘酚[(+)-1)与(一)-1-苯基-2-丙胺[(—)-2]·Cu(Ⅱ)络合物可以生成复合物沉淀,而在cu(Ⅱ)·胺络合物作用下,溶液中的光活性1发生消旋化作用,由(士)-1以76×10~(-2)的产率立体选择地制备了(+)-1和(—)-1。当用≥50×10~(-2)ee的2进行反应时,也可获得60×10~(-2)的光活性1。     

Syntheses of 4-Aryl Chromanes: A Rearrangement Approach

4-Aryl chromanes are synthesized from 4-Aryloxy chromanes via a rearrangement methodology.     

一种确定氧化数的新方法

氧化数是元素的重要性质,在无机化学中应用广泛。长期以来,确定元素氧化数主要根据桐山良一和鲍林等建立的规则,这些规则对于氧化数概念在化学中的推广普及起了很大的作用,但在遇到结构复杂或未知化合物时有时仍然会出现问题。本文根据IUPAC的氧化数定义提出,氧化数完全取决于成键两原子之间的电子供需关系,元素的最高正氧化数受到其原子价层电子数的限制,而元素的最低负氧化数受到同周期稀有气体元素外层电子数与其价层电子数差值的限制,据此建立了确定元素氧化数的新方法,该方法既不需要考虑分子结构,也不依赖元素氧化数的习惯规定,符合氧化数概念提出的初衷,简便易行,例外情况少,不仅适合大学化学教学,也适合中学化学教学。     

烃氧基丙二酸酯的新制备方法

烃氧基丙二酸酯在有机合成中是有用的试剂^[1],一般来讲,实验室的四类制备方法都有不足之处:(1)烃氧基乙酸酯与草酸酯或碳酸酯之间的酯缩合反应^[1~3]。     

计算分布分数的新方法

基于代数法建立了一种计算溶液中型体分布分数的新方法。方法仅需对pL及相关lgK作加减和常用对数运算 ,复杂体系也仅需增加少量以 10为底的乘方运算 ,因而方法简便 ,计算结果与传统代数法基本一致     

A New Chemiluminescence Method for the Determination of Pyrogallol

Pyrogallol(Py) is a chemiluminescence(CL) reagent with a low emission efficiency. The pyrogallol structural group is also found in molecules of many important natural and synthetic confounds, such as gallic acid humic acid and pyrogallol red. Studies of the metablism of phenolic compounds requires the development of specific and sensitive methods for the determination of pyrogallol. HPLC^[1], spectrophotometry^[2] and CL^[3-7] have been used to determined polyphenols, but these methods are complicated or low sensitivity.In this paper, a new Chemiluminense(CL) analytical method for determination of Py was established.This method is more sensitive than those methods reported in the literature^[3-7].     

合成3,3''''-二吲哚基苯基甲烷的新方法

以无水乙醚为溶剂,室温下无水三氯化铝催化N-(2-氯乙基)苯甲醛亚胺与吲哚反应,合成了3,3'-二吲哚基苯基甲烷和6,12-二苯基吲哚[2,3-b]咔唑,其结构经1H NMR,IR和MS表征.     

合成2-氟腺嘌呤的新方法

从2-氨基-6-氯嘌呤出发,通过叠氮化反应合成2-氨基-6-叠氮嘌呤(3),3在希曼反应中完成氟对氨基的取代得到2-氟-6-叠氮嘌呤(4),4的叠氮基被还原为氨基制备出目标化合物2-氟腺嘌呤,总收率39.3%。     

优氯净的分析测定新方法研究

本文利用优氯净对紫外光有吸收的特性,采用紫外分光光度法对优氯净的含量进行测定.实验考察了测定过程中可能存在的各种影响因素,证明此方法是一种简便的、高效可行的优氯净的分析方法.