Novel Base-Promoted Syntheses ofβ-Indolylketones via a Three- Component Condensation under Ultrasound Irradiation

In recent years, a wide variety of organic compounds bearing indole fragment have been attracted much attention due to the fact that many of them are pharmacologically and biologically active compounds.[1] Among them β-indolylketones are one of the most significant intermediates for the preparation of natural products such as hapalindole D 1.[2] In recent years, the utilization of multicomponent condensations (MCCs) to generate novel, drug-like scaffolds are replete in current organic reactions due to the fact that products can be prepared directly in a single step and the diversity can be achieved simply by varying the reaction substrates. In continuation of our work to synthesize new β-indolylketones,[3] herein, we report a novel base-induced syntheses of new β-indolylketones via a three-component condensation. Deoxybenzoin as carbonyl compound is introduced into the reaction (Scheme 1), and all the reactions were operated under ultrasound irradiation since the utilization of which can accelerate the progress of many reactions and shorten the reaction time.     

Design and Synthesis of 1-Benzyl-3-(a-hydroxy-(un)substituted benzylidene)pyrrolidine-2,4-diones as Potential Herbicides

The inhibitors of 4-hydroxyphenylpyruvate dioxygenase (HPPD, EC 1.13.11.27) are an new kind of herbicides.[1]Generally, in structure, potent herbicides of this kind must possess: (1) a tricarbonyl methane structure and one of the three carbonyl groups must be a subustituted benzoyl group; (2) the compound must be able to enolise so that the enolate is capable of inhibiting HPPD enzyme by competitive combination with Fe2+, the reaction center of HPPD enzyme.[2]Recently, we noticed that the 3-acyltetramic acids form an expanding group of antibiotics and pigments from micro-organisms,[3] they display a range of biological activities[4] and all of this kind compounds possess all of the characters mentioned above. Tests of their antimicrobial activities indicated that the structure of the acyl substituent at the 3-position was important to many typical antibiotics.[4～6] These characters stimulated us to study this kind of compounds so as to discover new herbicides. In this report, we synthesized a series of compounds 3 and tested their herbicidal activities to investigate their structure-activity relationships.     

Construction of photoresponsive supramolecular micelles based on ethyl cellulose graft copolymer

In this work, a UV-Visible light controlled supramolecular system based on ethyl cellulose(EC) was constructed, combining the host-guest interaction of β-cyclodextrin(β-CD) group and trans-isomer of azobenzene(tAzo) group. To link β-CD to the hydrophobic section, renewable EC was used as macroinitiator to initiate the polymerization of ε-caprolactone(ε-CL) to form biocompatible and biodegradable comb copolymer EC-g-PCL, and β-CD was attached to the end of PCL side chain via click reaction. Meanwhile, hydrophilic PEG-tAzo was obtained by N,N'-dicyclohexylcarbodiimide(DCC) coupling. Then, the structures of the products were characterized by nuclear magnetic resonance(NMR) and gel permeation chromatography(GPC). Subsequently, with the formation of inclusion complexes by β-CD and tAzo groups, the obtained EC-g-PCL-β-CD/PEG-tAzo supramolecular system self-assembled in water with hydrophobic EC-g-PCL-β-CD as core and hydrophilic PEG-tAzo as shell. Furthermore, dynamic light scattering(DLS) and transmission electron microscopy(TEM) were utilized to investigate the particle size and size distribution, while NMR and UV-Vis spectra were applied to explore the UV-Visible light stimuli-responsiveness of the micelles.     

Synthesis of chiral dihydrofuran compounds by thiourea derivatives-catalyzed“interrupted”Feist-Bénary reaction

<正>In this study,six thiourea derivatives of cinchona alkaloids with 9-nat or 9-epi-configuration were synthesized.After characterized the structures,we adopted them to the asymmetric"interrupted"Feist-Benary(IFB) reaction ofα-haloketones with β-dicarbonyl compounds,to give optically active dihydrofurans.Various thiourea derivatives as organocatalysts were examined.The corresponding chiral hydroxyl dihydrofurans have been obtained in excellent yields and moderate ees.To the acyclic substrate,we obtained exciting and promising result.     

An Expeditious Synthesis of β-Indolylketones Catalyzed by p-Toluenesulfonic Acid (PTSA) Using Ultrasonic Irradiation

The investigation of the chemistry of indoles has been, and continues to be, one of the most active areas of heterocyclic chemistry.[1] In particular, β-indolylketones have received much attention as important building blocks for the synthesis of many natural products and other biologically active compounds.[2] In continuation of our work in the synthesis of indole derivates,[3] we describe the remarkable catalytic of PTSA as a cheaper catalyst in ultrasound-accelerated Michael reaction of indole with α, β-unsaturated ketones (2), which provide one of the most efficient routes to the synthesis of β-indolyketones. In all cases, the substitution on the indole nucleus occurred exclusively at the 3-position, and N-alkylation products have not been observed. In addition, the structure of 3a was further confirmed by single crystal X-ray crystallography.     

C-H BOND ACTIVATION AND FUNCTIONALIZATION OF METHANE UNDER MILD CONDITIONS

In the presence of Rh(COD)(dppe)Cl (COD=1, 5-cyclootadiene, dppe=1,2-bis-(diphenylphosphino)ethane) and CO, we studied the H/Cl exchange reaction between CH_4 and o-dichlorobenzene, and observed that the active species of the reaction is a complex containing dppe and carbonyl ligands. We suggest that the mechanism of exchange reaction may be described by the elementary reaction of oxidative addition and reductive elimination. In the presence of trans-PtHL_2X (L=PEt_3, P(n-Pr)_3, P(n-Bu)_3, PPh_3; X=Cl~-, Br~-, I~-, CN~-) complexes, we have studied the oxidative chlorination reaction of methane. The catalytic activity was found to be related to the electron-donating properties and the cone angle of tertiary phosphine, as well as the trans-effect of X anionic ligands. In addition to the above reactions, we have also studied the insertion reaction of acetylene into C-H bond of methane catalyzed by organotransition-metal complexes containing heterocyclic chelate ligands, such as bipy, phen and TMEDA, in DMF     

Michael Reaction of 2,4-Dioxohexahydro-1,3,5-triazine

With the extensive investigation of the Michael reaction, not the methylene compounds activated by electron withdrawing group[1,2] but other activated unsaturated compounds containing such as activate N-H or O-H have been used as Michael acceptor.[3,4] However, the research on the Michael reaction of 2,4-dioxohexahydro-1,3,5-triazine (DHT) has not been reported. After the systematic researches on the substitution reactions of DHT, we first report the Michael reaction of DHT with acrylic esters in this paper.     

Synthesis and Crystal Structure of 7,7- Dimethyl-2-amino-3-cyano-4-(3,4-methylenedioxylphenyl)- 5-oxo-5,6,7,8-tetrahydro-4H-benzo-[b]-pyran

1 INTRODUCTION Inorganic solid supports as catalysts resulting in higher selectivity, milder conditions and easier work-up has been reported as useful catalysts for many reactions [1~3]. Recently, we have reported the Knoevenagel condensation and some other reactions[4~6] catalyzed by KF-Al2O3. In this paper, we discussed the crystal structure of the title compound synthesized by the reaction of 2-cyano-3-(3,4-methylenedioxylphenyl)acrylonitrile and 5,5-dimethyl-1,3-cyclohexanedione in…     

Study on Ionic Organotin Compounds Ⅲ. Synthesis of Five-Coordinated Anionic Tin(Ⅳ) Complexes and Crystal Structure of [ ( i-Pr)2NH2] [ PhSn(μ2-SCH2COO)2]

The study of ionic organotin compounds is of current attention owing to their diversified molecular structures and wide range of applications, such as biological activities[1 ～3] and as catalysts in organic synthesis. [4] Recently, we synthesized some new ionic organotin compounds by dephenylation reaction. [5] In this paper, we continued to study the reaction of mercaptoacetic acid with phenyltin trichloride in the presence of organic base. The reaction equation was as follows:     

ONE''''POT REACTION OF TRIVALENTPHOSPHORUS COMPOUNDS (Ⅰ)——A NOVEL ONE-STEP REACTION OF ADDITION,REDUCTION AND CYCLIZATION OF SUBSTITUTED β-NITROSTYRENE WITH O,O-DIALKYL PHOSPHITES

In this paper the reaction of substituted β-nitrostyrene with O,O-dialkyl phosphite under cocatalysis of trimethylsilyl chloride (TMS-C1) and triethylamine (or other acidbinding agent) has been first studied and the new cyclization reaction leading to the formation of product Ⅱ, as a new class of derivatives of 1-hydroxyindoles, difficultly accessible or inaccessible with usual methods has been observed. In the related reaction it is surprising that when the Arbuzov rearrangement occurs under mild conditions, the addition, reduction and cyclization as a one-pot reaction take place simultaneously with the formation of products Ⅰ, Ⅱ, Ⅲ. By controlling the reaction conditions the products were formed almost in specificity, and thus the most interesting cyclic products Ⅱ_(a-h) containing phosphorus-carbon bond were obtained. Their structures were confirmed by elemental analysis, IR, ~1H or ~(31)p NMR and MS spectra. The crystal structure of representative compound Ⅱ_h was determined by X-ray diffract     

用茂钛配合物高效、高选择性催化4-乙烯基环己烯的异构化

The catalytic species [Cp2TiH], formed in situ from the reaction of titanocene dichloride with Grignard reagents having a β-H, was found to be a very effective catalytic system for isomerization of diolefin[1～3]. Based on our previous work[3], the titanium-catalyzed isomerization of 4-vinyl-cyclohexene (VCH) was studied in some detail. In this communication, we report the use of various substituted titanocene and polymer-supported titanocene complexes with Grignard reagents as catalyst for the isomerization of VCH. It was reported that base-catalyzed isomerization of VCH formed a very complicated mixture with 60 % conversion[4].     

Synthesis and Crystal Structure of Ethyl2—（2—Amino—3—ethoxycarbonyl—4H—benzopyran—4—yl）cyanoacetate

1 INTRODUCTION Inorganic solid supports as catalysts resulting in higher selectivity, milder conditions and easier work-up have been reported as useful catalysts for many reactions [1~3]. Recently, we have reported the Knoevenagel condensation catalyzed by KF-Al2O3[4]. In this paper, we discussed the crystal structure of the title compound synthesized by the reaction of salicylaldehyde and ethyl cyanoacetate in DMF using the catalyst KF-Al2O3 at room temperature KF-Al2O3. In or…     

Regioselective 1,2-Addition of Ti(IV)-enolate to α, β–Unsaturated Compounds

The nucleophilic addition to α, β-unsaturated carbonyl compounds is a fundamental C-C bond forming reaction in organic chemistry1. Since there are two reaction sites in the α, β–unsaturated carbonyl group, the regioselectivity of the nucleophilic addition (1, 2 vs. 1, 4 addition) is of primary importance when applying this type of reaction in organic synthesis. Factors that control the regioselectivity include the softness and hardness of the attacking nucleophiles2, solvent and temperatu…     

Largely Improved Stretch Ductility and β-Form Room-temperature Durability of Poly(vinylidene fluoride) by Incorporating Aliphatic Polyketone

In this study, we attempt to prepare a new blending system of poly(vinylidene fluoride) (PVDF) and aliphatic polyketone (POK) by melt compounding. The latter is a promising engineering plastic with comprehensive mechanical performances. When POK acted as minor phase to homogeneously disperse in and intimately contact with PVDF matrix, the brittle tensile behavior of neat PVDF transferred into a remarkably flexible manner (the elongation at break increased for 20 times), and more interestingly, the roomtemperature durability of β-form PVDF in the uniaxially drawn blend film was obviously better than that in the neat PVDF film. Fourier transform infrared spectroscopy revealed that specific dipole interaction existed between CF_2 group of PVDF and C=O group of POK.The intermolecular dipolar interaction induced good compatibility in the PVDF/POK blends, as evidently proved by fine two-phase morphology and decreased melting points of POK crystals. Therefore, the good compatibility and interfacial enhancement are responsible for the improvement of the stretch ductility and β-form room-temperature durability of the PVDF/POK blends.     

Preparation of 1-Trifluoroethyl-4-methoxy-5-chloropyridazin-6-one: Methyl Shift of 4-Methoxy-5-chloropyridazin-6-one

N1-Trifluoroethyl-4-methoxy-5-chloro-3-pyridazone (4) was synthesized by the substitution reaction of 4methoxy-5-chloro-3-pyridazone (1) with trifluoroethyl trifluoromethanesulfonate (A) at basic condition. In the most of reaction conditions, N1-methyl-4-methoxy-5-chloro-3-pyridazone (2) was obtained as a major by-product, which means that the methyl group in the 4-methoxy shifted to N-1 position inter-molecularly aided by A or trifluoroethyl methanesulfonate (B). We obtained N1-methyl-4-trifluoro-ethoxy-5-chloro-3-pyridazone (3) in the reaction of 1 with B at higher temperature in different solvents with different yield (Table 1 ), which mechanism was shown in Figure 1. When we tried to synthesize 4 in the reaction of 1 with trifluoroethyl toluenesulfonate under basic condition, 6 was obtained (Figure 2). All the detailed mechanisms are undergoing investigated.     

INFLUENCES OF LIGANDS ON THE HOMOGENEOUS HYDROFORMYLATION OF ALKENE(I)-TRI-(3,4-DIMETHYLPHENYL)PHOSPHITE AS A LIGAND

In this paper we describe the effects of tri(3, 4-dimethylphenyl)phosphite[(3,4-(CH_3)_2C_6H_3O)_3P]or triphenylphosphine(PPh_3)used as ligand in the homogeneoushydroformylation of alkene using dicarbonyl acetylacetone rhodium as the parent catalyst.The reaction kineties has been investigated.It was found that tri(3,4-dimethylphenyl)-phosphite has greater activity and better selcctivity than PPh_3 for hydroformylation ofheptene-1.The results are discussed in terms of eiectronic and stereochemical effects.     

A Lewis acid-catalyzed tandem reaction enabling 2-arylglycerol derivative as a versatile 1,3-biselectrophile for the synthesis of 4H-chromenes and 2-pyridinones

Acid-catalyzed tandem reactions were established by employing a novel class of 2-arylglycerol derivative,5-aryl-1,3-dioxan-5-ol, as versatile 1,3-biselectrophile. In the reactions, 5-aryl-1,3-dioxan-5-ol works like atropaldehydes or 2-aryl malondialdehydes, and can react with 2-naphthols and β-keto amides, allowing the synthesis of 4H-chromenes and 5-aryl-2-pyridinones. High yields, good functional group tolerance,broad substrate scope and simple reaction operation make this protocol attractive.     

Tuning the optical properties of BODIPY dye through Cu(I) catalyzed azide-alkyne cycloaddition (CuAAC) reaction

Borondipyrromethenes(BODIPY) are a class of fluorescent dyes whose fluorescence quantum yields are generally high and independent of the solvent.In this paper,we report the synthesis of a new type of BODIPY compound that carries an azido group on the 3-position of the pyrrole core.The azido group quenches the fluorescence of the dye due to its weak electron-donating effect.The fluorescence of the BODIPY dye can be switched on after reacting with alkynes via a Cu(Ⅰ) catalyzed azide-alkyne cycloaddition(CuAAC) reaction.We further demonstrate that this azido-BODIPY compound can be used in the cell imaging applications.     

Synthesis and Crystal Structure of Copper(II) Complex with N-Acetoxyl-picolinamide

1 INTRODUCTION The picoloylhydrazide compounds are close to thebiologic environment and can react with microele-ments in organism so as to have antitubercular andantineoplastic activities. However, owing to the exis-tence of amino group, this kind of compounds aretoxic to some extent[1]. In order to decrease theirtoxicity, hydrazone or hydrazide compounds synthe-sized by the condensation reaction of amino and car-bonyl groups have been well studied in recentyears[1～7]. Herein we report t…