期刊文献+
共找到4,917篇文章
< 1 2 246 >
每页显示 20 50 100
Diastereoselective α-Alkylation of β-Amino Esters: Preparation of Novel α-Substituted β-Amino Esters from α-Amino Acids
1
作者 ZhiHuaMA CongLIU 《Chinese Chemical Letters》 SCIE CAS CSCD 2002年第8期721-724,共4页
Enantiomerically pure a-substituted bamino esters were prepared from natural L-a-amino acids through Arndt-Eistert homologation and diastereoselective aalkylation.
关键词 DIASTEREOSELECTIVITY ALKYLATION b-amino esters. Diastereoselective aAlkylation of bAmino esters: Preparation of Novel aSubstituted bAmino esters from aAmino acids Zhi Hua MA Cong LIU Yong Hua ZHAO Wei LI Jian Bo WANG* Key Laboratory of
下载PDF
Novel Phosphonoacetic Acid Derivatives.Synthesis of N-(Ethoxycarbonylmethylphosphonyl)-α-Amino Esters and-α-Amino Phosphonic Acid Esters and Their Bioactivities
2
作者 Hui Ying LI Kang Tai REN Ru Yu CHEN(Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071) 《Chinese Chemical Letters》 SCIE CAS CSCD 1997年第12期0-0,0-0,共4页
A series of novel phosphonoacetic acid derivatives, N-(ethoxycarbonylmethy-ethoxyphosphonyl)-α-amino acid esters and α-amino phosphonates, were synthesized via the reaction of the corresponding phosphonyl chloride ... A series of novel phosphonoacetic acid derivatives, N-(ethoxycarbonylmethy-ethoxyphosphonyl)-α-amino acid esters and α-amino phosphonates, were synthesized via the reaction of the corresponding phosphonyl chloride with amino acid ester hydrochlorides or amino phosphonates in the presence of a base. The preliminary bioassay shows that some compounds show significant anti-viral activity against tobacco mosaic virus (TMV) 展开更多
关键词 Novel Phosphonoacetic acid Derivatives.Synthesis of N cm PN Amino Phosphonic acid esters and Their Bioactivities Ethoxycarbonylmethylphosphonyl Amino esters and
下载PDF
Stereospecific Synthesis of α,β- didehydro-α-amino-4-phenylbutyric Acid Esters
3
《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 1999年第S1期221-221,共1页
关键词 Stereospecific Synthesis of amino-4-phenylbutyric acid esters didehydro
下载PDF
PREPARATION OF N-t-BUTYLOXYCARBONYL-O~α-9-FLUORENYLMETHYL ESTER OF ASPARTIC ACID
4
《Chinese Chemical Letters》 SCIE CAS CSCD 1995年第8期673-674,共2页
The preparation of the a carboxyl 9-fluorenylmethyl(FM) ester of Boc-aspartic acid is described.This new protected amino acid linked to the polymeric support by βcarboxyl group offers a convenient strategy for the sy... The preparation of the a carboxyl 9-fluorenylmethyl(FM) ester of Boc-aspartic acid is described.This new protected amino acid linked to the polymeric support by βcarboxyl group offers a convenient strategy for the synthesis of head-to-tail cyclopeptides while the peptides remained attached to the polymeric support. 展开更多
关键词 acid OF PREPARATION ester FLUORENYLMETHYL ASPARTIC BUTYLOXYCARBONYL
下载PDF
Study on the Total Synthesis of 3-Oxo-9β-Acetoxyilicic Acid─The Synthesis of 9β-Acetoxy-3(4),11(13)-Dien-5αH,7αH-12-Eudesmanoic Acid Methyl Ester
5
作者 Jiong YANG Zbao Ming XIONG Yong Gang CREN and Yu Lin LI(National Laboratory of Applied Organic Chemistry and Institute of Organic Chemistry,ho University, Lanzhou 730000) 《Chinese Chemical Letters》 SCIE CAS CSCD 1997年第12期0-0,共2页
The synthesis of 99-acetoxy-3(4), 11(13)-dien-5αH 7αH-12-eudesmanoic acid methyl ester (2) was achieved from oxycarvone. The key step is the p-toluenesulfonhydrazide assisted reductiv rearrangement reaction
关键词 The Synthesis of 9 H 7 H-12-Eudesmanoic acid Methyl ester Dien-5 Study on the Total Synthesis of 3-Oxo-9 Acetoxyilicic acid Acetoxy-3
下载PDF
The Synthesis of Some Novel N-[α-(Isoflavone-7-O-) Acetyl]Amino Acid Derivatives 被引量:1
6
作者 Peng LIU Jun Biao CHANG +2 位作者 Rong Feng CHEN Qiang WANG Jing Xi XIE (Henan Institute of Chemistry, Henan Academy of Science, Zhengzhou 450002 Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050) 《Chinese Chemical Letters》 SCIE CAS CSCD 2000年第5期391-394,共4页
A series of novel N-[α-(isoflavone-7-O-)acetyl] amino acid methyl esters were prepared from the efficient and regioselective alkylation of isoflavones with chloroacetyl amino acid derivatives under mild condition.
关键词 Isoflavone analogues N-[α-(isoflavone-7-O-)acetyl] amino acid methyl ester synthesis.
下载PDF
Screening of Degrading Bacteria for Phthalic Acid Esters Under Cadmium Stress and Its Application
7
作者 ZHOU Bing-yu ZHOU Yu +2 位作者 WANG Chun-ping LIU Fen LIU Biao 《Agricultural Science & Technology》 CAS 2024年第3期50-56,共7页
In order to enrich the degrading microbial resources for phthalic acid esters(PAEs)under cadmium stress,a degrading bacterium B-7 for di(2-ethylhexyl)phthalate(DEHP)was screened from the strains stored in the laborato... In order to enrich the degrading microbial resources for phthalic acid esters(PAEs)under cadmium stress,a degrading bacterium B-7 for di(2-ethylhexyl)phthalate(DEHP)was screened from the strains stored in the laboratory by means of inorganic salt liquid medium containing DEHP and cadmium,and the characteristics of the strain were studied.Strain B-7 was Bacillus amyloliquefaciens,which had high biosafety and excellent degradability to DEHP.The optimum temperature for degradation was 25–40℃,and the optimum pH value was 6–8.Strain B-7 was cultured in inorganic salt medium(MSM)with an initial DEHP concentration of 400 mg/L and cadmium content of 10 mmol/L for 4 d,and its degradation rate of DEHP was up to 93.1%.In addition,the strain had a strong degradation ability to dimethyl phthalate(DMP),diethyl phthalate(DEP),and dibutyl phthalate(DBP).In soil contaminated by cadmium and DEHP,the synergic degradation of B-7 and indigenous microorganisms in soil significantly increased the degradation rate of DEHP,indicating that this strain had potential application value in the field of microbial remediation of soil contaminated by cadmium and PAEs. 展开更多
关键词 Phthalic acid esters CADMIUM Bacillus amyloliquefaciens Soil bioremediation
下载PDF
Recent Advances of Sensitive Electrochemical Sensing Platforms for Rapid Detection of Phthalate Acid Esters
8
作者 Xiuxiu Dong Lili Zhang +2 位作者 Meicai Ge Minfu Wu Qijian Niu 《Instrumentation》 2024年第2期9-23,共15页
As a kind of plasticizer,phthalic acid esters(PAEs)are often added to plastics to enhance elasticity,transparency,durability and prolong service life.However,it does not chemically bind to plastics and is easy to migr... As a kind of plasticizer,phthalic acid esters(PAEs)are often added to plastics to enhance elasticity,transparency,durability and prolong service life.However,it does not chemically bind to plastics and is easy to migrate to the environment.It is difficult to degrade in the environment,and it is also enriched in the human body through the food chain and respiration,which will lead to obvious adverse reactions such as decreased learning and memory function and neurobehavioral disorders.Due to the toxicity,universality and low concentration limitations of PAEs in the environment and food,it is essential to achieve rapid and sensitive detection of PAEs in soil,atmosphere,water and food.Electrochemical(EC)sensors have the advantages of simplicity,fast,low cost,portability,easy operation,high specificity and high sensitivity,so they are applied for the detection of PAEs.Although there are a large number of studies on the detection of PAEs by EC sensors,there is no review on this aspect.In this review,we introduce the detection of PAEs from classical EC sensors,electrochemiluminescence(ECL)sensors and photo-electrochemical(PEC)sensors in the past five years.This review is beneficial to understanding the construction of EC sensors and the detection mechanism of PAEs.We also propose that the development of rapid,accurate and real-time detection methods of PAEs is key to assessing risk and preventing related diseases. 展开更多
关键词 phthalate acid esters electrochemical sensor DETERMINATION
下载PDF
Free amino group-directed C(sp^(2))-H arylation ofα-amino-β-aryl esters by palladium catalysis
9
作者 Yue Gao Yu Du Weiping Su 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第2期358-360,共3页
Native amino-directed palladium-catalyzed C(sp^(3))-H activation/functionalization has been developed for modification ofα-amino acids and peptides.Herein a palladium(Ⅱ)-catalyzed C(sp^(2))-H arylation ofα-amino-β... Native amino-directed palladium-catalyzed C(sp^(3))-H activation/functionalization has been developed for modification ofα-amino acids and peptides.Herein a palladium(Ⅱ)-catalyzed C(sp^(2))-H arylation ofα-amino-β-aryl esters has been disclosed,using the native amino as the directing group.A variety of chiralα-amino-β-aryl esters can be functionalized to give the corresponding ortho-substituted mono-and di-arylated products. 展开更多
关键词 Native amino-directed Palladium catalyst C(sp^(2))-H arylation α-Amino-β-aryl ester Chiralα-amino acid
原文传递
α-甲基丙烯酸十四酯-十六烯降凝剂的合成及其降凝效果 被引量:12
10
作者 宋程鹏 汪树军 +2 位作者 刘红研 杜涛 刘宁 《石油化工》 CAS CSCD 北大核心 2009年第8期879-883,共5页
用α-甲基丙烯酸和十四醇合成了α-甲基丙烯酸十四酯(TDMA);以甲苯为溶剂、过氧化苯甲酰(BPO)为引发剂,TDMA与十六烯(HE)共聚生成了降凝剂α-甲基丙烯酸十四酯-十六烯二元共聚物(AH);对TDMA和AH进行了红外光谱表征;考察了影响AH降凝效... 用α-甲基丙烯酸和十四醇合成了α-甲基丙烯酸十四酯(TDMA);以甲苯为溶剂、过氧化苯甲酰(BPO)为引发剂,TDMA与十六烯(HE)共聚生成了降凝剂α-甲基丙烯酸十四酯-十六烯二元共聚物(AH);对TDMA和AH进行了红外光谱表征;考察了影响AH降凝效果的主要因素以及将AH与两种市售降凝剂分别复配后的降凝效果。实验结果表明,以在n(TDMA)∶n(HE)=6∶1、BPO用量(相对于单体TDMA和HE的质量分数)1.0%、甲苯用量(相对于单体TDMA和HE的质量分数)75%、聚合时间5h的条件下合成的AH为降凝剂,在AH用量(相对于基础油的质量分数)为0.5%时,AH的降凝效果最佳,可使燕山500SN、燕山200SN、河南、湖南和大庆5种基础油的凝点分别降低29,31,20,6,18℃;AH与市售降凝剂复配后,复配物对基础油的降凝效果基本优于单独使用市售降凝剂的降凝效果。 展开更多
关键词 α-甲基丙烯酸 十四醇 α-甲基丙烯酸十四酯 十六烯 α-甲基丙烯酸十四酯-十六烯二元共聚物 降凝剂 基础油
下载PDF
α-酮酸酯的合成研究进展 被引量:4
11
作者 王宇婷 张青枝 +1 位作者 张深松 封惠侠 《有机化学》 SCIE CAS CSCD 北大核心 1996年第4期310-322,共13页
α-酮酸及其酯是一类双官能团化合物,性质活泼而特殊,是重要的有机合成、药物合成及生物合成中间体。本文扼要论述了近二十年来α-酮酸酯的合成研究进展。
关键词 α-酮酸 α-酮酸酯 α-羟基酸酯 羧酸酯
下载PDF
α-酮酸、α-酮酸酯及α-酮酰胺的合成进展 被引量:8
12
作者 祝馨怡 苏桂琴 +2 位作者 张伟强 张玉华 殷元骐 《合成化学》 CAS CSCD 2001年第5期390-396,共7页
详细综述了双羰化反应和格氏试剂、草酸二乙酯一步法制备不同结构的α 酮酸、α 酮酸酯及α 酮酰胺的研究进展 ,参考文献 2
关键词 双羰化反应 格氏试剂 草酸二乙酯 α-酮酸 α-酮酸酯 α-酮酰胺 合成 药物中间体
下载PDF
Anticancer Activities of Substituted Cinnamic Acid Phenethyl Esters on Human Cancer Cell Lines 被引量:4
13
作者 李树春 李辉 +2 位作者 张法 李中军 崔景荣 《Journal of Chinese Pharmaceutical Sciences》 CAS 2003年第4期184-187,共4页
Caffeic acid phenethyl ester (CAPE) and sixteen substituted cinnamic acid phenethyl esters were prepared via conventional procedures in order to test their in vitro anticancer activities by either MTT assay or SRB... Caffeic acid phenethyl ester (CAPE) and sixteen substituted cinnamic acid phenethyl esters were prepared via conventional procedures in order to test their in vitro anticancer activities by either MTT assay or SRB assay on six different human cancer cell lines. The results indicated that in the concentration of 10 μmol·L -1 the lead compound CAPE possessed anticancer activities against human HL 60, Bel 7402, and Hela cell lines, and two other compounds possessed potent anticancer activities against Bel 7402 and Hela cell lines. 展开更多
关键词 medicinal chemistry cinnamic acid phenethyl esters chemical synthesis anticancer activity
下载PDF
Two New Phenolic Carboxylic Acid Esters from Opuntia vulgaris
14
作者 蒋建勤 叶文才 +2 位作者 陈真 楼凤昌 闵知大 《Journal of Chinese Pharmaceutical Sciences》 CAS 2002年第1期1-3,共3页
Two new phenolic carboxylic acid esters n-butyl eucomate(1) and methyl eucomate (2) and six known compounds eucomic acid(3), 3-β-acetyl-taraxerol (4), friedelin(5),lupenone(6),methyl linoleate(7) and methy... Two new phenolic carboxylic acid esters n-butyl eucomate(1) and methyl eucomate (2) and six known compounds eucomic acid(3), 3-β-acetyl-taraxerol (4), friedelin(5),lupenone(6),methyl linoleate(7) and methyl oleate(8) were isolated from the stems of Opuntia vulgaris Mill(Cactaceae). Their structures were determined on the basis of spectral methods. Compounds 3,4,6,7,8 were isolated for the first time from this plant. 展开更多
关键词 Opuntia vulgaris Phenolic carboxylic acid ester n-Butyl eucomate Methyl eucomate
下载PDF
β-(3,4-二羟基苯基)-α-羟基丙酸异丙酯/冰片酯合成研究 被引量:14
15
作者 张群正 董岩 +2 位作者 南叶飞 蔡雪刁 郑晓晖 《有机化学》 SCIE CAS CSCD 北大核心 2009年第9期1466-1469,共4页
以3,4-二羟基苯甲醛为起始原料,经苄基保护、Darzens环氧化、Lewis酸开环、NaBH4还原、催化加氢脱保护得到β-(3,4-二羟基苯基)-α-羟基丙酸异丙酯和β-(3,4-二羟基苯基)-α-羟基丙酸冰片酯,所得化合物的结构通过1HNMR、13CNMR,IR,MS证... 以3,4-二羟基苯甲醛为起始原料,经苄基保护、Darzens环氧化、Lewis酸开环、NaBH4还原、催化加氢脱保护得到β-(3,4-二羟基苯基)-α-羟基丙酸异丙酯和β-(3,4-二羟基苯基)-α-羟基丙酸冰片酯,所得化合物的结构通过1HNMR、13CNMR,IR,MS证实.该方法操作简单、毒性低、产物易于纯化. 展开更多
关键词 酯化 β-(3 4-二羟基苯基)-α-羟基丙酸异丙酯 β-(3 4-二羟基苯基)-α-羟基丙酸冰片酯 超强酸催化
下载PDF
微波催化合成α-亚麻酸植物甾醇酯技术研究 被引量:9
16
作者 刘昌盛 王明霞 +2 位作者 李江涛 钮琰星 黄凤洪 《食品科学》 EI CAS CSCD 北大核心 2008年第7期213-216,共4页
采用微波技术合成α-亚麻酸植物甾醇酯,研究了植物甾醇和α-亚麻酸不同摩尔比、催化剂添加量、微波功率、反应时间对α-亚麻酸植物甾醇酯产率的影响。正交优化α-亚麻酸甾醇酯合成的优化工艺条件为:α-亚麻酸与植物甾醇的摩尔比3.5:1,... 采用微波技术合成α-亚麻酸植物甾醇酯,研究了植物甾醇和α-亚麻酸不同摩尔比、催化剂添加量、微波功率、反应时间对α-亚麻酸植物甾醇酯产率的影响。正交优化α-亚麻酸甾醇酯合成的优化工艺条件为:α-亚麻酸与植物甾醇的摩尔比3.5:1,微波功率660W,反应30min(4min/次,加热8次),甲醇钠添加量0.75%,此时α-亚麻酸甾醇酯的产率为60.8%;产品经重结晶后产品纯度达90.2%。 展开更多
关键词 微波 α-亚麻酸 植物甾醇 α-亚麻酸植物甾醇酯
下载PDF
PW_(12)/SnO_2催化合成α-亚麻酸植物甾醇酯 被引量:7
17
作者 何则强 熊利芝 梁凯 《中国油脂》 CAS CSCD 北大核心 2010年第2期33-36,共4页
用SnO2固载磷钨杂多酸(PW12/SnO2)催化合成α-亚麻酸植物甾醇酯,研究了醇酸摩尔比、反应温度、催化剂用量、反应时间等因素对酯化率的影响。实验结果表明:PW12/SnO2是合成α-亚麻酸植物甾醇酯的优良催化剂,在植物甾醇与α-亚麻酸摩尔比... 用SnO2固载磷钨杂多酸(PW12/SnO2)催化合成α-亚麻酸植物甾醇酯,研究了醇酸摩尔比、反应温度、催化剂用量、反应时间等因素对酯化率的影响。实验结果表明:PW12/SnO2是合成α-亚麻酸植物甾醇酯的优良催化剂,在植物甾醇与α-亚麻酸摩尔比为1∶3,催化剂用量为(占总反应物料的质量分数)0.6%,温度50℃,反应时间5 h条件下,植物甾醇的酯化率为85.92%,所得产品α-亚麻酸植物甾醇酯的纯度为91.7%。 展开更多
关键词 固载杂多酸 SNO2 α-亚麻酸 植物甾醇 α-亚麻酸植物甾醇酯
下载PDF
N-[芳氧乙酰基]α-氨基膦酸二苯酯的合成 被引量:1
18
作者 刘军安 石德清 +4 位作者 盛梓良 吴宏 刘小鹏 朱鳞 鹿鹿 《合成化学》 CAS CSCD 2002年第4期329-332,共4页
通过取代芳氧乙酸与α-氨基膦酸二苯酯的缩合反应合成了 1 2个未见报道的目标化合物 ,用元素分析 ,IR,1 H NMR确定了化合物的结构。
关键词 N-[芳氧乙酰基]α-氨基膦酸二苯酯 合成 芳氧羧酸 α-氨基膦酸酯 除草剂
下载PDF
生物催化法水解制备N-BOC-L-α-氨基丁酸 被引量:4
19
作者 王宇光 叶秋娟 +1 位作者 吴冬梅 魏春 《发酵科技通讯》 CAS 2016年第3期129-132,共4页
利用实验室筛选得到的高立体选择性脂肪酶产生菌株溜曲霉(Aspergillus tamarii WYC3)不对称水解拆分N-BOC-DL-α-氨基丁酸甲酯得到N-BOC-L-α-氨基丁酸,对其反应条件进行研究,确定其最优反应条件为:0.1 mol/L p H 7.2的磷酸钾缓冲液,反... 利用实验室筛选得到的高立体选择性脂肪酶产生菌株溜曲霉(Aspergillus tamarii WYC3)不对称水解拆分N-BOC-DL-α-氨基丁酸甲酯得到N-BOC-L-α-氨基丁酸,对其反应条件进行研究,确定其最优反应条件为:0.1 mol/L p H 7.2的磷酸钾缓冲液,反应温度30℃,底物浓度52.24 mmol/L,0.1 g菌粉,V(底物)∶V(丙酮)=1∶8,200 r/min恒温水浴反应6 h,可获得产物N-BOC-L-α-氨基丁酸,此时e.e._(s)值达到99.95%,对映体选择率E值为20.11,产率为36.21%。 展开更多
关键词 N-BOC-DL-α-氨基丁酸甲酯 N-BOC-α-氨基丁酸 ASPERGILLUS tamarii WYC3 水解反应 工艺优化
下载PDF
α-酮酸酯的生物活性及合成研究进展 被引量:2
20
作者 谢媛媛 蒋筱莹 《浙江工业大学学报》 CAS 北大核心 2016年第1期78-83,共6页
α-酮酸酯及其衍生物是一种双官能团化合物,结构特殊,是有机合成及生物代谢的重要中间体,具有广泛的生物学活性,被用于各种酶抑制剂及生物碱的合成,同时它也是一类重要的医药合成中间体,在有机合成及药物研发中具有重要意义.为了促进α... α-酮酸酯及其衍生物是一种双官能团化合物,结构特殊,是有机合成及生物代谢的重要中间体,具有广泛的生物学活性,被用于各种酶抑制剂及生物碱的合成,同时它也是一类重要的医药合成中间体,在有机合成及药物研发中具有重要意义.为了促进α-酮酸酯及其衍生物的研究与发展,在此总结并综述了该类化合物的生物活性,其生物活性主要体现在对各类酶的抑制作用上,从而能够达到治疗各种疾病的目的.此外,阐述了近年来研究报道的几种简便高效的合成该类化合物的新方法,并对这些方法进行了评价,在该类化合物的合成与发展上具有一定的指导和借鉴意义. 展开更多
关键词 α-酮酸 α-酮酸酯 生物活性 酶抑制剂 合成
下载PDF
上一页 1 2 246 下一页 到第
使用帮助 返回顶部