氨基偶氮苯磺酸钠系列中间体的合成

采用保护氨基的方法，合成了氨基偶氮苯磺酸钠系列中间体，经IR及13C NMR表征表明，合成得到的产品结构与理论结构相符，进一步说明此合成方法是可行的。     

2,6-二氧杂双环[3.2.1]辛烷类衍生物的串联合成

以2-甲基-4-戊烯-1,2-二醇和芳香醛为原料, 三氯化铟为催化剂, 得到了一系列1,3-二取代2,6-二氧杂双环[3.2.1]辛烷类衍生物. 整个反应采用一锅法, 反应条件简单且产率高. 所有的化合物均用¹H NMR, ¹³C NMR和质谱法进行了表征, 并用NOESY确立了分子的相对构型.     

An Efficient Stereoselective Synthesis of Key Fragments of Elaiophylin

The stereoselective synthesis of key fragments 3 and 7 of elaiophylin has been accomplished from readily available epichlorohydrin as the starting material. The key reactions involved are Jacobsen's kinetic resolution, Prins cyclization, pyridinium chlorochromate‐mediated oxidative cleavage, Grignard reaction, and cross‐metathesis reaction.     

Efficient one-pot construction of unsymmetrical disulfide bonds with TCCA

We report herein a one-pot synthesis of unsymmetrical disulfides with trichloroisocyanuric acid (TCCA) as an oxidant. Under facile conditions, aromatic-aromatic disulfides and aromatic-aliphatic disulfides were synthesized in good to excellent yields even without base. For the construction of the challenging aliphatic-aliphatic disulfides, good yields of the desired products were also obtained with slightly modified conditions. Additionally, the reactions demonstrated a wide range of substrate scope, very short reaction time (<5 min), and convenient procedures.     

Facile and Efficient Enantioselective Strecker Reaction of Ketimines by Chiral Sodium Phosphate

Asymmetric catalysis : A facile enantioselective Strecker reaction of ketimines with trimethylsilyl cyanide (TMSCN) was realized by employing chiral (S)‐BNPNa 3 e and PBAP as an additive (see image). A wide substrate scope and good‐to‐excellent enantioselectivities were achieved.

     

A Facile Synthesis of Substituted N-Benzoylthiourea

Abstract

One pot reaction of benzoyl isothiocyanate and Tris(hydroxy- methyl)aminomethane (Tris) at room temperature with polyethylene glycol-400 (PEG-400) as solid–liquid phase-transfer catalyst produced substituted N-benzoylthioureas with high yield. A reasonable pathway for their formation has been suggested.     

Intermolecular Double Prins‐Type Cyclization: A Facile and Efficient Synthesis of 1,6‐Dioxecanes

Double or nothing : The title reaction converts a range of aromatic aldehydes and allenylmethyl/allyl silanes into 1,6‐dioxecane derivatives in good to excellent yields (see scheme; Ar=aryl, Tf=triflate, THF=tetrahydrofuran, TMS=trimethylsilyl). In addition, the bisdiene product has been transformed into the corresponding tricyclic compound through a Diels–Alder reaction.

     

Efficient One-pot Synthesis of Pyrrolo[2,1-a]isoquinoline and Pyrrolo[1,2-a]quinoline Derivatives

A one-pot sequential reaction for efficient synthesis of pyrrolo[2,1-a]isoquinoline and pyrrolo[1,2-a]-quinoline derivatives has been developed. The reaction included firstly the Cu-catalyzed three-component reaction of isoquinoline(quinoline), acetylenedicarboxylate and alkynylbenzene and then Cs₂CO₃-promoted intramolecular cyclization reaction of initially formed 1-alkenyl-2-alkynyl-1,2-dihydroisoquinoline(1,2-dihydroquinoline).     

Efficient Synthesis of Flaccidoside II,a Bioactive Component of Chinese Folk Medicine Di Wu

A bidesmosidic triterpene saponin, flaccidoside II, which was isolated from Di Wu, a Chinese folk medicine from dry rhizome of Anemone flaccida Fr. Schmidt, was efficiently synthesized in a convergent approach. We employed two glycosyl trichloroacetimidate donors in a one-pot reaction as a key step.

[Supplementary materials are available for this article. Go to the publisher's online edition of the Journal of Carbohydrate Chemistry for the following free supplemental resource(s): ¹H NMR, ¹³C NMR and HR mass spectra for all synthesized compounds, 2, 6, 9-11, and Flaccidoside II (1)     

Synthesis and two-photon absorption of triphenylbenzene-cored dendritic chromophores

The synthesis and the characterization of triphenylbenzene-cored dendrimers of first- and second-generation are described. Their absorption, photoluminescence as well as their two-photon absorption properties have been investigated and compared to a quadrupolar counterpart. These molecules combine wide transparency in the visible range and high two-photon absorption cross-sections that increase with the generation, making these dendrimers promising systems for optical power limiting applications.     

Efficient synthesis of diarylidene octahydroacridines by one-pot multi-component tandem reactions

A one-pot multi-component reaction is developed for the efficient synthesis of 4,5-dibenzylidene octahydroacridines in high yields. The reaction is performed by the tandem reaction of three molar equivalent aromatic aldehydes with two molar equivalent 4-alkylcyclohexanone in the system of NH₄OAc/HOAc under microwave irradiation.      

Highly Efficient Synthesis of Bis（indolyl）methanes Catalyzed by Sodium Tetrafluoroborate

Sodium tetrafluoroborate （NaBF4） was found to catalyze the electrophilic substitution reactions of indoles with aldehydes and ketones under solvent-free conditions to afford the corresponding bis（indolyl）methanes in high yields.     

Efficient Horner-Wadsworth-Emmons intramolecular cyclisation of a N-substituted phthalimide promoted by KF-Alumina: a general tool for the synthesis of functionalised isoindolinones

An intramolecular Horner-Wadsworth-Emmons reaction promoted by KF-Alumina involving a N-substituted phthalimide, cleanly and efficiently furnishes an interesting α,β-unsaturated tricyclic enone which may undergo selective alkylations at the α′-position.     

Efficient Synthesis of Sivelestat Sodium Hydrate

An efficient and scaleable synthesis of sivelestat sodium hydrate has been developed.     

Efficient Synthesis and Antitumor Activities of Indioside E Analogs

An efficient synthesis of seven analogs of a naturally occurring saponin, indioside E, is described. The synthesis used a 3,4,6-O-protected D-galactopyranosyl thioglycoside as the key intermediate to enable regioselective glycosylation and one-pot multistep reactions. Antitumor activities of the synthetic saponins against a human hepatocellular carcinoma cell line BEL-7402 and a human breast adenocarcinoma cell line MCF-7 were evaluated by means of the CCK-8 assay. Analogs carrying trisaccharides with the D-xylopyranose in indioside E substituted with a D-ribopyranose and an L-arabinopyranose or with its diosgenin aglycon replaced with tigogenin exhibited similar antitumor activities as indioside E, but not other analogs.     

亚硫酸氢钠作链转移剂合成低分子量聚丙烯酸钠

采用水溶液聚合法,以K2S2O8-NaHSO3氧化还原体系为引发剂、NaHSO3为链转移剂,合成了低分子量聚丙烯酸钠.对实验条件进行了优化,结果表明:反应温度70℃,单体丙烯酸质量分数为20%~30%,NaHSO3与K2S2O8质量比为10∶1~14∶1,反应时间5h,可获得分子量为2000~4000的聚丙烯酸钠.     

Zirconium-mediated Selective Synthesis of Quinoline Derivatives

A series of quinoline derivatives was obtained in high yields by an efficient one-pot reaction of substituted o-diiodobenzenes with azazirconacyclopentadienes, which were conveniently prepared from one internal alkyne and one nitrile mediated by zirconocene. This proposed synthetic method provides a feasible way to the synthesis of large N-heterocyclic π-conjugated molecules.