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排序方式: 共有481条查询结果,搜索用时 46 毫秒
31.
利用改进的Sonogashira反应一锅法合成了一例未见报道的叁键桥联的联吡啶类化合物L[2,6-二(3'-吡啶乙炔基)-4-甲基苯胺],与常规的分步合成方法相比,新方法不需脱除保护,从而简化了反应步骤,提高了产率.对所合成的化合物利用红外、核磁、元素分析等确定了其结构,并进一步利用X射线单晶衍射法测得了该化合物的单晶结构.单晶分析显示该化合物结晶于正交晶系、Pca21空间群中,a=10.178A,b=10.972A,c=28.949 A;a=β=γ=90°,Z=8.该化合物在配位化学方面具有潜在的应用前景.我们测定了其固态下的荧光性质,显示其能够发出较强的蓝色光. 相似文献
32.
以硅胶固载硫酸镧作为催化剂,由芳香醛、β-酮酸酯和脲(硫脲)合成了相应的3,4-二氢嘧啶-2(1H)-酮化合物,考察了苯甲醛、乙酰乙酸乙酯、脲三组分发生Biginelli反应时的催化剂用量、反应物物质的量比、反应时间及催化剂重复使用对反应收率的影响;并利用核磁共振谱(1H NMR)和红外光谱(IR)表征了合成产物的结构... 相似文献
33.
新型5-溴嘧啶衍生物的选择性合成 总被引:1,自引:0,他引:1
对甲苯磺酰氯与三甘醇单甲酯完成酯化反应,再与对溴苯酚缩合制得对溴苯基三甘醇单甲醚(3);3与硼酸甲酯完成取代反应、酸解后在Pd(PPh3)4催化下与5-溴-2-碘嘧啶(5)在甲苯中通过Suzuki偶联反应选择性地合成了5-溴-2-对(甲基三甘醇基)苯基嘧啶(1a),收率73%。以1-十二烯和5为主要原料,通过Suzuki偶联反应,一锅法选择性地合成了5-溴-2-十二烷基嘧啶(1b),收率82%。1a和1b未见文献报道,其结构经1HNMR,13C NMR和MS表征。 相似文献
34.
Abhisek Kar Dr. Jamsad Mannuthodikayil Sameer Singh Anamika Biswas Puneet Dubey Dr. Amit Das Dr. Kalyaneswar Mandal 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(35):14906-14911
We report an operationally simple method to facilitate chemical protein synthesis by fully convergent and one-pot native chemical ligations utilizing the fluorenylmethyloxycarbonyl (Fmoc) moiety as an N-masking group of the N-terminal cysteine of the middle peptide thioester segment(s). The Fmoc group is stable to the harsh oxidative conditions frequently used to generate peptide thioesters from peptide hydrazide or o-aminoanilide. The ready availability of Fmoc-Cys(Trt)-OH, which is routinely used in Fmoc solid-phase peptide synthesis, where the Fmoc group is pre-installed on cysteine residue, minimizes additional steps required for the temporary protection of the N-terminal cysteinyl peptides. The Fmoc group is readily removed after ligation by short exposure (<7 min) to 20 % piperidine at pH 11 in aqueous conditions at room temperature. Subsequent native chemical ligation reactions can be performed in presence of piperidine in the same solution at pH 7. 相似文献
35.
以甲醇为溶剂,以醛、胺、硫代乙酸和3-(二甲氨基)-2-异氰基丙烯酸甲酯为原料,经四组份一锅法反应合成了9个新型的2-取代噻唑-4-甲酸衍生物,产率25%~54%,纯度90.3%~100%,其结构经1H NMR,13C NMR和LC-MS表征。 相似文献
36.
A green and efficient method for direct preparation of 3-cyanopyridine from aromatic aldehydes is reported. A series of novel 4-aryl-2-amino-6-(naphthalene-1-yl)-3-cyanopyridine derivates were successfully prepared by one-pot synthesis of three-component domino reactions including aromatic aldehydes, 1-acetylnaphthalene, and dicyanomethane in the presence of ammonium acetate in a solution of ethanol under microwave irradiation. This synthetic method for these compounds possesses many advantages including greater yield and shorter reaction times compared with traditional methods. The structures of these compounds were confirmed by means of high-resolution mass spectrometry, 1H NMR, 13C NMR, and infrared. Moreover, the results of their fluorescent spectra showed that these compounds have good fluorescence intensity excited by the visible light wavelength of 416 nm. 相似文献
37.
An efficient one-pot synthesis of 3-amino-7-azaindoles was developed, starting from ethyl (3-cyanopyridin-2-yl)carbamate and α -bromoketones by microwave-assisted Thorpe–Ziegler cyclization in the presence of a base. This method features excellent yields, short reaction time (10min), and high functional group compatibility.
[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.] 相似文献
38.
在SDS-PVP水溶液中采用N2H48226;H2O还原CuSO4, 在pH (10±0.5), (40±1.0) ℃条件下反应55 min得到橙色Cu2O溶胶, 离心分离产物经XRD鉴定为Cu2O立方晶系晶体; SEM和TEM表明该法获得的晶体为形状规整、粒径分布窄的Cu2O中空亚微球, 并证实系由大量10 nm量级的原级Cu2O纳米晶粒组装而成. 根据实验事实推断, SDS-PVP项链状软团簇提供了“双重软模板”功能, 借助独特的“模板诱导两级组装”作用一锅法合成了Cu2O中空亚微球. Cu2O中空亚微球生长的可能途径为: 首先, 项链状软团簇中的SDS束缚胶束作为第一重软模板, 诱导一级组装10 nm量级的原级Cu2O纳米晶粒; 然后, 软团簇中立体桥联SDS束缚胶束的PVP链节作为第二重软模板, 诱导一定空间范围内的原级Cu2O纳米晶粒长大并进一步聚集/二级组装, 经一锅法合成得到次级Cu2O中空亚微球. 实验结果证明该一锅法温和、简便、快捷, Cu2O中空亚微球的粒径分布窄. 相似文献
39.
BALALAIE Saeed CHADEGANI Fatemeh DARVICHE Fatemeh BIJANZADEH Harnid Reza 《中国化学》2009,27(10):1953-1956
A new and efficient method for the synthesis of 1,8‐dioxo‐9‐aryl‐decahydroacridine derivatives was developed via a one‐pot three component reaction of dimedone, aromatic aldehydes and ammonium acetate in the presence of ammonium chloride, or Zn(OAc)2·2H2O or L‐proline separately in water in the short period of time and high yields. 相似文献
40.
Wangyu Li Mingteng Xiong Xiao Liang Dungai Wang Heping Zhu Prof. Dr. Yuanjiang Pan 《ChemistryOpen》2022,11(1):e202100268
An electro-oxidative cyclization pathway in which hydrazones are selected as starting materials to generate amphiphiles by reacting with benzylamines and benzamides was reported. This strategy successfully prepared a series of 1,2,4-triazoles in satisfactory yields. Moreover, the use of cheap stainless steel as the anode, the feasibility to conduct the transformation as a one-pot reaction and the proof that scaling-up these reactions is possible make this transformation attractive for potential application in industry. 相似文献