有机锗氨基酸酯类系列化合物的快原子轰击质谱规律

为增强有机锗化合物的生物活性，合成了一系列有机锗氨基酸酯类倍半氧化物，并重点研究了它们的快原子轰击质谱（ＦＡＢＭＳ）。研究结果表明：该系列化合物的各碎片离子峰与其组成及结构均有很好的对应关系及很强的规律性     

EPA甲酯和DHA甲酯标准样品的制备和结构解析

从鱼油中分离制备得到二十碳五烯酸（EPA）甲酯和二十二碳六烯酸（DHA）甲酯,采用红外光谱、质谱、核磁共振波谱等手段对EPA甲酯和DHA甲酯的结构进行表征,提供了不饱和脂肪酸甲酯标准物质研制基础。样品的红外光谱（IR）、质谱（MS）、核磁共振谱图（1HNMR、13CNMR）所给出的结构信息与EPA甲酯和DHA甲酯的化学结构式相符,并通过DEPT谱和I3C-1H COSY化学位移相关谱（HMBC）对各共振峰进行了指认,样品的谱图数据与文献报道基本一致。     

Hydride Transfer Reactions of Aminomethylphosphines and Bis(Amino)Methanes with Diphenylboric Acid Ester in the Presence of Carbonyl Compounds

Abstract

The interaction of diethylaminomethylphosphines and diphenylboric acid isobutyl ester proceeds only in the presence of active carbonyl compounds, namely alkyl aldehydes, followed by the formation of 1,3,2,5-dioxaborataphosphoniarinanes with the second molecule of the carbonyl compound. Reactions don't take place in the presence of ketones and aromatic aldehydes. Bis(N,N-diethylamino)methane reacts analogously to give corresponding N,B-containing zwitter-iones.     

New Reagents for the Reductive Quenching of Ozonolysis Reactions

3,3′-Thiodipropionic acid and its salts were found to be effective reductive quench reagents in the ozonolysis of olefins. They were as effective as methyl sulfide without its drawbacks. A polymer-bound form of 3,3′-thiodipropionic acid was also effective.     

Sulfonyl Hydrazones of Cyclic Amides and Quaternary Azo Sulfones of Heterocycles as Reagents in Azo Chemistry

Sulfonyl hydrazones of cyclic amides undergo oxidative coupling with phenols and reactive methylene components. The reaction proceeds via the azo sulfones, which may be used as such, and which, as ambident cations, enter into many reactions with nucleophiles and extend the scope of oxidative coupling. The reaction with phenols is a two-step process, in which the limiting cases k₁ ? k₂, k₁ ≈ k₂, and k₁ ? k₂ can be realized by slight variation of the reactants.     

New Way for the Preparation of 4-Phenyl-2-oxobutyric Acid Ethyl Ester

New way for the preparation of 4-phenyl-2-oxobutyric acid ethyl ester 1 has been elaborated. The four-steps synthesis from ethyl pyruvate involves the consecutive condensation of ethyl pyruvate with benzaldehyde, hydrogenation of benzylidenepyruvic acid sodium salt 2a to 4-phenyl-2-hydroxybutyric acid 3 on Ni catalysts, esterification of 3 and oxidation of the ester to 1 with CrO₃.     

手性糖基锌卟啉对手性氨基酸甲酯的分子识别

合成了手性四糖基取代锌卟啉(Zn-A)的三种阻转异构体αβαβ-Zn-A、ααββ-Zn-A和αααβ-Zn-A以及一种单糖基取代锌卟啉(Zn-B), 并通过可见光谱滴定法和圆二色(CD)光谱滴定法研究了它们对手性氨基酸甲酯(L/D-LeuOMe, L/D-ThrOMe, L/D-ValOMe和L/D-PheOMe)客体的分子识别行为. 研究发现, 三种锌卟啉对L型氨基酸甲酯的缔合常数均要高于D型, 其中ααββ-Zn-A的对映体选择性(K_L/K_D)最高可达4.75, 可用于L型氨基酸甲酯的选择性识别. 不同的Zn-A 阻转异构体对手性氨基酸甲酯的缔合常数给出相同的顺序:K^θ(LeuOMe) > K^θ(ValOMe) > K^θ(ThrOMe) > K^θ(PheOMe);主体Zn-B对手性氨基酸分子的缔合常数顺序为K^θ(PheOMe) > K^θ(LeuOMe) > K^θ(ValOMe) > K^θ(ThrOMe). 同时, 以咪唑为探针分子研究了非手性分子对Zn-A构象的影响, 发现非手性分子咪唑与手性主体结合后, 也可对主体的构象产生影响. Zn-A的三种阻转异构体与氨基酸甲酯和咪唑类客体的缔合常数关系均为K^θ(ααββ-Zn-A) > K^θ(αβαβ-Zn-A) > K^θ(αααβ-Zn-A).     

手性锌卟啉与氨基酸酯的分子识别性能

通过紫外-可见光谱滴定法, 研究了手性锌卟啉配合物[p-(L-Leu)C2O-TPPZn]与手性氨基酸酯客体在CHCl3中的分子识别行为. 实验结果表明, D型氨基酸酯的缔合常数比L型的大, 且缔合常数按K(AlaOCH3)相似文献   

Lewis酸诱导芳基三氮烯为底物的Stille偶联反应研究

首次以芳基三氮烯为新型亲电底物进行Stille偶联反应研究.反应在室温、氩气保护下进行.溶剂、两底物物质的量比、催化剂用量等影响收率的因素被优化,取得最佳的优化条件,获得较好的收率.芳基三氮烯通过助催化剂路易斯酸迁移到钯化合物,偶联反应由钯催化剂催化完成.产物纯化通过硅胶柱层析完成,结构被1H NMR,13C NMR确定.     

反应性马来酸十二酯在苯丙乳液制备中的应用

马来酸酐与月桂醇反应合成了马来酸十二酯(1),以1为反应型乳化剂制备了苯丙乳液(2和2′).对2和2′的结构与性能进行了初步研究,探讨了聚合工艺、反应时间、单体转化率、温度等对2′性能的影响.制备2′的最佳反应条件为:w(1)=2.5%,用水量50%-60%,采用预乳化法,于75℃～80℃反应6 h,单体转化率96.2...     

3,5-二硝基苯甲酸淀粉酯的合成及应用

高分子吸附剂;3;5-二硝基苯甲酸淀粉酯的合成及应用     

1,2-联烯亚砜和1,2-联烯砜的反应

1,2-联烯亚砜和1,2-联烯砜是重要的含硫联烯化合物.综述了1,2-联烯亚砜和1,2-联烯砜的亲核加成、亲电加成、Diels-Alder反应、1,3-偶极加成、[2+2]环加成等反应以及在天然产物中的应用.     

Preparation of Solid,Substituted Allylic Zinc Reagents and Their Reactions with Electrophiles

The treatment of various allylic chlorides or bromides with zinc dust in the presence of lithium chloride and magnesium pivalate (Mg(OCOtBu)₂) in THF affords allylic zinc reagents which, after evaporation of the solvent, produce solid zinc reagents that display excellent thermal stability. These allylic reagents undergo Pd‐catalyzed cross‐coupling reactions with PEPPSI‐IPent, as well as highly regioselective and diastereoselective additions to aryl ketones and aldehydes. Acylation with various acid chlorides regioselectively produces the corresponding homoallylic ketones, with the new C? C bond always being formed on the most hindered carbon of the allylic system.     

脱氧胆酸类分子钳对氨基酸甲酯的手性识别

紫外光谱法;脱氧胆酸类分子钳对氨基酸甲酯的手性识别     

ω-苯基-(2S)-N-叔丁氧羰基氨基酸乙酯的制备

格氏试剂和N-叔丁氧羰基焦谷氨酸乙酯反应生成中间体ω-苯基-δ-氧代-(2S)-N-叔丁氧羰基氨基酸乙酯, 分别用对甲基苯磺酰肼和醋酸硼氢化钠结合的一锅法还原或Pd/C催化氢化还原中间体得到ω-苯基-(2S)-N-叔丁氧羰基氨基酸乙酯.