Direct Transformation of Esters into Heterocyclic Fluorophores

Despite the manifold use of heterocyclic fluorophores, only a fraction of the desired dye diversity can be accessed by contemporary synthetic approaches. Herein, we describe a modular method that converts various carboxylic acid esters directly into a broad spectrum of heteroanthrylium fluorophores. The double addition of heteroatom‐bridged 1,5‐bifunctional organomagnesium reagents to esters leads to the formation of acridinium, xanthylium, and SiR fluorophores after dehydrative acidic work‐up. This one‐step synthetic method provides access to organophotoredox catalysts for dual catalysis with nickel and dyes amenable to fluorescence enhancement.     

Synthesis of Cholesteryl Esters of Heterocyclic Analogs of Cinnamic Acid and Hetaroyloxycinnamic Acids by the Wittig Reaction

The reaction of cholesteryl triphenylphosphonioacetate chloride with heterocyclic aldehydes and hetaroyloxyarenecarbaldehydes in the presence of base gave the corresponding cholesteryl esters of substituted propenoic acids possessing liquid crystal properties.     

Aminohydroxypropane Esters of Hydroxyethylidenebisphosphonic Acid

Abstract

The 1-hydroxyethylidene-1,1-bisphosphonic acid (HEDP) (I) reacts with epichlorohydrine (II) and aminoepoxypropanes (III) in water. Optimum pH for the esterefication is 6–7. The reaction completes in 20–30 h on 60°C at this pH and leads to the mixture of the original HEDP with the mono- and diesters. The mixture of di-Na salts of HEDP and the monochloroester (IV) in ratio 1:1.7 was precipitated from the reaction solution on using of the epichlorohydrine (II). This mixture was used for synthesis of aminoesters (VI a,b) unavailable by direct reaction of HEDP with corresponding aminoepoxides.     

香豆素丙二酸二甲酯类化合物的合成

运用拼合原理将丙二酸酯类降糖活性化合物的药效基团丙二酸酯基与有降糖活性的香豆素拼合,设计合成3个新的了香豆素丙二酸甲酯类化合物,其结构经1H NMR,IR和MS表征。     

苯丙烯酸羟基香豆素酯类化合物的合成

咖啡酸的酚羟基不作保护,直接与氯化亚砜作用生成酰氯,再与羟基香豆素类化合物完成缩合反应合成了一系列苯丙烯酸羟基香豆素酯类化合物(1a～1j),其结构经1H NMR和元素分析表征,其中1a,1c～1e为新化合物.     

Mild Transformation of Telluro and Seleno Esters into Carboxylic Acid and Esters

Te-Butyl Telluroesters and Se-Butyl Selenoesters are hydrolyzed to carboxylic acids under very mild conditions by reaction with copper(II) chloride dihydrate. When the reaction is performed in ethanol or methanol, using anhydrous copper(II) chloride a transesterification occurred leading to the oxygenated esters in good yield.     

一硫代焦磷酸酰胺酯的合成

TEPP和OMPA都是较早发现的具有较高杀虫活性的药剂,但由于它们对温血动物毒性高而影响广泛应用^[1].许多化学家发现当焦磷酸酯中P=O上的氧原子被硫原子代替,或者烧氧基被取代氨基代替,可大大降低对温血动物的毒性而仍保持其对昆虫的毒性^[2,3].     

Some Conversions of Thiazoline Carboxylic Acid Esters

We have carried out solvolysis of the previously described ethyl esters of 3-methyl(aryl)-4-methyl-2-thioxothiazoline-5-carboxylic acids, leading to the corresponding acids without breaking down the heterocycle. We synthesized a series of novel esters from the latter by treatment with dimethyl sulfate or reactive halides. Of these, only in the case of the ethyl ester of 3,4-dimethyl-2-thioxothiazoline-5-carboxylic acid did we obtain the hydrazinolysis product (the hydrazide), from which we synthesized novel hydrazones by treatment with aldehydes and ketones.     

A Novel Synthesis of Squaric Acid Esters

A new procedure for the synthesis of the benzylic ester of the squaric acid is described. A first example of the reaction silyl ‘enol ether’ of the squaric acid with an electrophile in the presence of a fluoride source to give an O-alkylated product is described.     

New Synthesis of Substituted Cyclopropanephosphonic Acid Esters

Abstract

Aminocyclopropane phosphonic acids are considered to be “transition state analogues” of aminocyclopropanecarboxylic acids and they may serve as enzyme inhibitors¹. We attempted to synthesise aminocyclopropane derivatives by a new route². Phosphonoacetic acid allylic esters were subjected to an intramolecular, radical cyclisation in the presence of iodine, solid potassium carbonate and phase transfer catalyst.     

4－N－茄呢基氨基苯甲酸糖酯的合成

在氢氧化钠和四丁基溴化铵存在下，将化合物4－N－茄呢基氨基苯甲酸（3） 分别与O－乙酰基溴代葡萄糖、O－乙酰基溴代半乳糖、O－乙酰基溴代乳糖和O－乙 酰基溴代麦牙糖反应制得对应的糖酯4a-4d，由元素分析，IR，~1H NMR，~(13)C NMR和MS确证了四个新化合物的结构，并做了几种抗癌生理活性测试。     

聚甘油脂肪酸酯的结构鉴定

该文采用傅里叶变换离子回旋共振质谱（FT－ICR－MS）、核磁共振氢谱（1H NMR）以及气相色谱－质谱（GC－MS）技术,对聚甘油脂肪酸酯的结构进行鉴定。样品溶解后进行FT－ICR－MS测定,根据精确分子离子数据,推测出聚甘油脂肪酸酯的基本结构以及甘油的聚合度,并采用1H NMR进行了验证。将聚甘油脂肪酸酯水解后,对脂肪酸部分进行甲酯化,经正庚烷萃取,由GC－MS测定,分析脂肪酸的组成。综合以上结果最终确定了聚甘油脂肪酸酯的结构。该研究为聚合物的结构鉴定提供了一种新的思路和方法。     

Design,Synthesis, and Antioxidant/Antidiabetic Activity of Nucleic Acid Bases Bearing Fused N,S‐Heterocyclic Phosphor Esters

Reactions of unsaturated and saturated Wadsworth–Horner–Emmons reactants with N¹‐ and N³‐allyl‐2‐thiouracils, under phase‐transfer catalysis conditions, resulted in the respective N‐bridged thiazolo‐, pyrrolo‐, and thiazino‐phosphor esters. Products were obtained via the regioselective attack of the Wadsworth–Horner–Emmons reagent on the allylic‐1′‐C in tandem of double bond migration processes, followed by a series of transformations. Synthesis of pyrimidin‐1(2H, or 6H)‐yl)but‐1‐ene‐1,1‐diyldiphosphonates was also described. On the basis of the prediction results (PASS program, Moscow, Russia; free available internet version of PASS 2009.1: http://www.ibmc.msk.ru/PASS ), we further estimated the antioxidant and antidiabetic activities of the synthesized compounds. The results showed that all compounds cause moderate to good antidiabetic activities. However, the thiazolophosphonates exhibited the highest inhibitory antioxidant activity; nevertheless, the diphosphonates manifested the best protective effects against DNA damage induced by bleomycin. Biological testing confirmed the results of computational modeling.     

氨基酸卟啉锌配合物对氨基酸酯的分子识别研究(英文)

用紫外可见吸收光谱滴定方法研究了一种新型的苏氨酸卟啉锌配合物(主体)对氨基酸酯(客体)的分子识别.这种锌卟啉可以与氨基酸酯形成 1:1和 1:2的两种加合物.氨基酸酯的氨基首先与氨基酸残基的羧基作用形成 1:1的加合物,然后与锌卟啉的中央锌原子配位形成 1:2的加合物,客体分子与主体分子上的氨基酸残基之间的排斥作用以及主客体之间的色散力作用是主体分子能识别客体分子的另外两种作用。