Nonaromatic corroles: regioselectivity of electrophilic substitution

Ring contraction of nickel meso-tetraarylporphyrins produced nonaromatic divalent corroles bearing a benzoyloxy function. We investigated their reactivity under electrophilic conditions: formylation, halogenation, nitration. We also found that the benzoate function could be eliminated to afford deoxocorroles, and we tested the formylation and nitration in this deoxo series. These corroles were generally very stable under the reaction conditions, and in both series, the directly bonded pyrroles were the most reactive. The nitration reaction produced a series of corrole dimers via electron transfer initiated coupling.     

水相条件下1,4-二氢吡啶衍生物的合成与芳构化

将醛、乙酰乙酸乙酯和醋酸铵的多组分反应引入到水相回流条件下, 合成了一系列具有生物和药物活性的1,4-二氢吡啶化合物. 在此基础之上, 向反应体系中直接加入氧化剂MnO2, “一锅法”生成了芳构化的吡啶衍生物, 将原来Hantzsch酯的合成与芳构化在“一锅”里实现, 缩减了反应步骤, 提高了反应效率.     

Efficient method for the synthesis of chiral pyrrolidine derivatives via ring-closing enyne metathesis reaction

[reaction: see text] A series of new pyrrolidine derivatives were prepared directly in very good yields, from the substrates containing a basic or nucleophilic N atom via ring-closing enyne metathesis reaction under mild reaction conditions. Moreover, the reaction occurs smoothly without the presence of ethylene gas.     

Synthesis of New and Novel N-Protected 1-Aminoalkyl-2-naphthol Derivatives

A series of three-component reactions has been carried out using HClO₄-SiO₂ as a versatile heterogeneous catalyst. A series of new and novel N-protected 1-aminoalkyl-2-naphthol derivatives have been prepared under thermal solvent-free reaction conditions. In all cases, the reaction conditions were very simple and high-yielding.     

Radical cation salts induced domino reaction of anilines with enol ethers:Synthesis of 1,2,3,4-tetrahydroquinoline derivatives

A domino reaction of anilines with cyclic and acyclic enol ethers induced by catalytic amounts of TBPA^·+（5 mol%） was investigated and a series of 2,4-disubstituted-1,2,3,4-tetrahydroquinolines were synthesized.Different from cyclic enol ethers, when acyclic enol ethers were used in the reaction,they serve as surrogates of acetaldehyde,producing a series of 2-methyl-4- anilino-1,2,3,4-tetrahydroquinolines.A single electron transfer mechanism was proposed to rationalize the products formation.     

Synthesis,in-vitro antibacterial and anticancer screening of novel nicotinonitrile-coumarin hybrids utilizing piperazine citrate

Abstract

An efficient, low-cost, high yield% and eco-friendly synthetic procedure is designed for the synthesis of novel series of nicotinonitrile-coumarin hybrid molecules bearing several aryl and/or heteroaryl moieties. Our strategy includes the synthesis of a novel series of 2-hydroxybenzaldehydes, bearing nicotinonitrile moiety, followed by its Knoevenagel reaction with ethyl acetoacetate in the presence of an organo-base. The above reaction is studied in different reaction conditions. The optimized conditions are performing the reaction in ethanol at 80?°C in the presence of 10?mol% of piperazine citrate (1:1). The in-vitro antibacterial activities of the nicotinonitrile-coumarins were evaluated against different Gram-positive and negative bacterial strains. Moreover, the in-vitro cytotoxicity of nicotinonitrile-coumarins were estimated against different eukaryotic cell lines. Compounds 5a and 5b exhibited the most promising antibacterial agents among the novel series. The structures of novel series of the target nicotinonitrile-coumarin hybrid molecules were confirmed by considering their elemental analyses and spectral data.     

The Synthesis of Distamycin Analog Containing Phosphonyl Group

In order to obtain high biological activity compound, a series of distamycin analog containing phosphonyl group were synthesized by chloroform reaction and coupling reaction using DCC/HOBT as promoting additives.     

Catalytic thia-Sommelet-Hauser rearrangement: application to the synthesis of oxindoles

A series of 3-arylthio-1,3-disubstituted-oxindoles were prepared in good yields by the reaction of α-diazocarbonyl compounds and sulfenamides. The reaction involves a Rh-catalyzed thia-Sommelet-Hauser-type rearrangement.     

Studies of rearrangement reactions of protonated and lithium cationized 2-pyrimidinyloxy-N-arylbenzylamine derivatives by MALDI-FT-ICR mass spectrometry

The rearrangement reactions of protonated and lithium-cationized 2-pyrimidinyloxy-N-arylbenzylamine derivatives were studied by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and infrared multiphoton dissociation mass spectrometry (IRMPD). Our results show that three kinds of rearrangement reactions occur in IRMPD processes. First, nearly all protonated 2-pyrimidinyloxy-N-arylbenzylamine derivatives undergo Pathway A to form the K ion series. It is proposed that this rearrangement (migration of a substituted benzyl group) proceeds by way of a gas-phase intramolecular S(N)2 reaction. Second, a gas phase intramolecular S(N)Ar type rearrangement mechanism is proposed to explain the formation of the F ion series from protonated and lithium-cationized 5 (or 6). This skeletal rearrangement reaction competes with the S(N)2 reaction of the Pathway A, which produces the K ion series, in IRMPD of protonated 5 and 6. Third, the formation pathway of the W ion series is explained by a gas phase Cope type rearrangement mechanism.     

Synthesis and Characterization of Some Novel Dichromophoric Cyanine Dyes

Here, the synthesis of two novel series of dichromophoric cyanine dyes were reported. The first series of novel bis-azacyanine dyes 3a–d was afforded by reaction of 2-(1,3,3-trimethyle indoline-2-ylidene)acetaldehyde with diaminoaromatics, and the second series of novel bis-diazacyanine dyes 4a–d was obtained using quaternization of an amine group in disazo compounds, which were produced by the reaction of disazoaromatics with 2-methylene-1,3,3-trimethyle indoline. The products were identified by ¹H NMR, ¹³C NMR, infrared, UV-vis, and mass spectroscopy.     

An efficient synthesis of fluorine-containing substituted spiro[piperidine-4,4′-pyrano[3,2-c]quinoline]-3′-carbonitrile by nonconventional methods

A series of fluorine-containing substituted spiro[piperidine-4,4′-pyrano[3,2-c]quinolines] were synthesized through a rapid one-pot multi-component reaction under microwave irradiation and sonication. The method has the advantages of excellent yields (80-96%) and short reaction time (3-10 min). We provide a series of fluorinated quinoline derivatives interesting for biological screening tests.     

Cleavable chiral auxiliaries in 8pi (8pi, 6pi) electrocyclizations

[reaction: see text] Low to moderate diastereoselectivity was observed in the 8pi electrocyclization of a series of chiral auxiliary-bearing tetraenic esters. In the 8-arylmenthyl series, diastereomeric products were separated by chromatography.     

硫酸铜催化合成二元酸系列酯

以硫酸铜为催化剂,合成了２０种二元酸系列酯,结果表明,该催化剂具有活性好、操作简便、无三度污染、酯收率高、可多次重复使用等优点。经正交试验得出已下酯较佳的合成工艺条件。     

3,3'-二取代联二萘酚硫脲催化合成4H-吡喃衍生物

合成了3种3,3′-二取代BINOL轴手性硫脲类催化剂(3a~3c),并成功地将其应用于催化不对称Knoevenagel-Micheal的串联反应。结果表明,以CH2Cl2为溶剂、3a为催化剂各种取代芳香醛与丙二腈和1,3-环己二酮在25℃下反应得到4H-吡喃衍生物,产率可达98%,对映选择性高达94%。     

Modular synthesis of cyclic peptidomimetics inspired by gamma-turns

[reaction: see text] A series of peptidomimetics based on a gamma-turn motif were synthesized using a modular approach, in which N-protected piperidones were reacted with a selection of 2-hydroxyalkyl azides derived from common l-amino acids. Hydrolysis of the initially formed iminium ethers afforded the targeted series of substituted 1,4-diazepin-5-ones.     

PEG-400为绿色反应介质无催化一锅法合成2-氨基-3-氰基-4-芳基-4H-苯并色烯衍生物

PEG-400为绿色反应介质下无催化萘酚、丙二腈及芳香醛三组分“一锅法”高产率地得到了苯并色烯衍生物. 该反应具有产率高、污染少、操作简单、环境友好等优点, 产物的结构通过红外光谱和核磁共振谱进行了表征.     

无金属参与的二乙酸碘苯促进吲哚C3—H乙酸化反应

研究了无金属参与的二乙酸碘苯和吲哚的C3—H乙酸化反应,通过对取代基效应、温度以及二乙酸碘苯用量等因素的考察,建立了反应的最佳条件:反应温度60℃,乙酸(HOAc)为溶剂.在无需任何添加剂条件下,以中等到良好的收率获得一系列C3位乙酸化的吲哚衍生物.采用红外光谱、核磁共振波谱、高分辨质谱及X射线单晶衍射分析对目标化合物进行了结构表征,并推测了可能的反应机理.该催化体系对于克量级规模反应均能获得很好的结果.     

A comparative study of triphenylamine,triphenylphosphine, triphenylarsine,triphenylantimony and triphenylbismuth as ligands in the rhodium-catal yzed hydroformylation of 1-dodecene

Triphenylarmine, triphenylphosphine, triphenylarsine, triphenylantimony and triphenylbismuth were evaluated on the basis of olefin to aldehyde conversion, and also on the basis of the normal/iso (n / i) product ratio, as ligands in the rhodium-catalyzed hydroformylation of 1-dodecene. Two series of reactions were conducted which differed only in total reaction time (120 minutes vs 135 minutes) and in the ligand/rhodium ratio (60:1 vs 300:1). Both reactions series employed 35 grams of 1-dodecene, a 176 ppm rhodium charge, 100 psig of 1:1 H₂ / CO, and a reaction temperature of 90° C. In the 60:1 vs 330:1 reaction series, triphenylamine gave olefin conversions and n / i ratios of 2.0%, 2.0 vs 5.8%, 1.8; triphenylphosphine gave 95%, 4.4 vs 86.9%, 8.7; triphenylarsine gave 58%, 3.1 vs 85.8%, 3.5; triphenylantimony gave 13.0%, 6.1 vs 3.5%, 9.1 respectively. Triphenylbismuth failed to promote hydroformylation in both reaction series. These data demonstrate that regiospecificity, as measured by the n / i product ratio, varies inversely to increased ligand basicity.     

Reaction of arylidene-2-naphthylamines with ethyl furoylacetate

The reaction of arylidene-2-naphthylamines with ethyl furoylacetate was studied. It is shown that noncyclic amino keto esters are formed when the reaction is carried out without a catalyst and that esters of the benzo[f]quinoline series are formed when the reaction is carried out in the presence of a catalyst and an oxidizing agent. Esters of the benzo[f]quinoline series are also formed in the cyclization of the amino keto esters. The structures of the reaction products were confirmed by the results of elementary analysis and the IR, UV, NMR, and mass spectroscopic data.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 169–172, February, 1979.     

NaBF4催化合成二吲哚甲烷类化合物

在乙醇水溶液中,以Na BF4为催化剂,通过吲哚与芳香醛间的串联反应合成了二吲哚甲烷衍生物。考察了催化剂种类、反应介质、温度、反应时间等因素对反应的影响,在优化条件下以较高产率得到了一系列目标产物。