Solventless Friedel-Crafts Acylation under Microwave Activation

A novel catalytic system, ZnCl2 supported on alumina, was found to be an efficient and readily available medium for the solvent-free Friedel-Crafts acylation reactions under microwave irradiation. Good yields and high catalytic efficiencies were observed within short reaction times. Comparing with silica gel, alumina was more efficient under the same conditions.

Friedel-Crafts Acylation of Ferrocene Catalyzed by Solid Superacid,Silica-supported Polytrifluoromethanesulfosiloxane

Solid superacid, silica-supported polytrifluoromethanesulfosiloxane (SiO2-Si-SCF3) wasfirstly used in the Friedel-Crafts acylation of ferrocene as a novel catalyst. IR spectra, WAXD andspecific surface area of the superacid SiO2-Si-SCF3 were also investigated.

Friedel-Crafts Acylation Reactions Using Catalytic SbCl_5-TEBA Complex as an Efficient Catalyst

SbCl_5-TEBA (PhCH_2NEt_3Cl) complex catalyzes the Friedel-Crafts acylation reactionsefficiently.

The Synthesis of 4-Arylcarbonyl-3-methoxycarbonyl-2-phenylfurans by Friedel-Crafts Acylation Reactions

Keto esters 8, 4-arylcarbonyl-3-methoxycarbonyl-2-phenylfurans, potential precursors of the synthesis of furofuran lignans, were obtained from dimethyl 2-phenylfuran-3,4-dicarboxylate 2. Diester 2 was selectively hydrolyzed to monoacid 6 followed by converting to its acid chloride 7. Friedel-Crafts acylation reactions of 7 with aromatic compounds afforded keto esters 8. The geometric structures of 8 and its precursors were elucidated and verified by NMR spectra.

A Novel Friedel-Crafts Acylation Reaction of Anisole for Production of 4-Methoxyacetophenone with High Selectivity and Sufficient Reusability of Mordenite Zeolite Catalyst

Zeolite catalyzed Friedel-Crafts reactions were examined using acetic anhydride as an acetylating agent and an acetic acid as a solvent. It revealed that the reaction of anisole smoothly occurred quantitatively for 3 h using mordenite zeolite with SiO2/Al2O3 = 200, and with SiO2/Al2O3 = 110, the increasing of Br?nsted acidity allowed to completely react within 2 h. Furthermore the selectivity of 4-methoxyacetophenone (4-MA) among the isomers was found to be quantitative, no by-products and/or isomers were not detectable. With the excellent recyclability and reusability, the mordenite zeolite exhibited at least 30 times quantitatively both conversion of anisole and selectivity of 4-MA. The mordenite catalysts of fresh and the used after 30 times were characterized. This opportunity obviously indicates the sufficient shape selective catalyst of mordenite zeolite and gives a green synthetic tool for heterogeneous acylation reaction.

The Friedel-Crafts Acylation of Substituted Benzene with 2 - Phenylfuran-3, 4-dicarboxylic Acid Anhydride

2-Phenylfuran-3,4-dicarboxylic acid anhydride reacted with seven aromatic compounds, of which five gave keto acids in yields of 94%-63%. The structure of the keto acid was elucidated by reducing it to hydroxy acid and analyzing with NMR technique.

Prussian Blue Analogue Derived N-Doped Graphitic Carbon Wrapped Iron-Cobalt Nanoparticles as Recyclable Heterogeneous Catalysts for Friedel-Crafts Acylation

The rational design of efficient heterogeneous catalysts for Friedel-Crafts acylation reactions is highly desirable for meeting the need for the industrial production of various aromatic ketone compounds and biomass-derived chemicals.Herein,we reported that graphitic carbon wrapped FeCo bimetallic nanoparticles confined in nitrogen-doped carbon nanotubes,which were prepared by pyrolysis of FeCo-based Prussian blue analogue and melamine via a two-stage programmed heating procedure,exhibited excellent catalytic activity and recyclability for the acylation of aromatic compounds with acyl chlorides.The oxidized bimetallic species embedded in the external graphitic carbon shell should be the main active sites for the acylation reaction.The graphitic carbon shell and the carbon nanotube could provide effective protection on the active metal species against leaching through multiple interactions,leading to the formation of a highly active and durable heterogeneous catalyst for the acylation reaction.

Metal-organic framework MIL-53(Al): synthesis, catalytic performance for the Friedel-Crafts acylation, and reaction mechanism

Metal-organic framework MIL-53(Al) was synthesized by a solvothermal method using aluminum nitrate as the aluminium source and 1,4-benzenedicarboxylic acid(H2BDC) as the organic ligand. The structure of samples was characterized by X-ray diffraction(XRD) and Fourier transform infrared spectroscopy(FT-IR). The catalytic activity and recyclability of MIL-53(Al) catalyst for the Friedel-Crafts acylation reaction of indole with benzoyl chloride were evaluated. The reaction conditions were optimized and a reaction mechanism was suggested. The results showed that the MIL-53(Al) catalyst exhibited good catalytic activity and recyclability for the Friedel-Crafts acylation reaction. When the molar ratio of indole and MIL-53(Al) catalyst was 1:0.06(n1:ncatalyst), the molar ratio of indole and benzoyl chloride was 1:3, and the solvent was dichloromethane, the conversion of indole could reach 97.1% and the selectivity of 3-acylindole could reach 81.1% at 25 °C after 8 h. The catalyst can be reused without significant degradation in catalytic activity. After the catalyst was reused five times, the conversion of indole was 87.6% and the selectivity of 3-acylindole was 79.5%.

低价钛引起的酰氯与脂肪酮的还原偶联反应

在低价钛(TiCl_4-Zn)试剂作用下,酰氯与两分子脂肪酮发生分子间交叉还原偶联反应生成烯烃3。

油溶性抗氧化剂脂肪酰表儿茶素的合成及其清除自由基活性

本实验采用酰化反应法合成了油溶性抗氧化剂脂肪酰表儿茶素,并对其进行了清除自由基活性评价。以表儿茶素为原料,分别以棕榈酰氯、豆肉蔻酰氯、月桂酰氯、癸酰氯、辛酰氯为酰化剂,经酰化反应制备了表儿茶素的棕榈酰、豆肉蔻酰、月桂酰、癸酰、辛酰衍生物,通过LC-MS、1H-NMR对其结构进行了表征,并采用DPPH法和ABTS法考察其抗氧化活性。结果表明:本方法制备了含不同脂肪链的表儿茶素脂肪酰衍生物3-O-棕榈酰表儿茶素、3-O-豆肉蔻酰表儿茶素、3-O-月桂酰表儿茶素、3-O-癸酰表儿茶素、3-O-辛酰表儿茶素。经酰化后的脂肪酰表儿茶素仍具有较强的抗氧化和清除自由基能力;其抗氧化能力普遍优于市售的油溶性茶多酚和BHT,其中3-O-辛酰表儿茶素和3-O-癸酰表儿茶素清除ABTS+.自由基能力稍强于TBHQ;其清除DPPH.自由基的能力与TBHQ相当。

α,β-不饱和酮的逆合成分析

通常情况下采用羟醛缩合对α,β-不饱和酮进行逆合成分析,在羟醛缩合切断不理想的情况下,根据目标物的具体结构,还可以运用脂肪族Friedel-Crafts酰基化反应、Nazarov环化反应、Baylis-Hillman反应串联分子内Stetter反应以及Diels-Alder反应对α,β-不饱和酮进行逆合成分析。

低价钛引起的酰氯与脂肪酮的还原偶联反应

在低价钛（TiCl_4—Zn）试剂作用下,酰氯与脂肪酮发生分子间交叉还原偶联生成烯烃。

Synthesis and Thermal Crosslinking Behavior of Poly(aryl ether ketone)s Containing 1,4-Naphthalene Moieties

A new monomer, 1,4-bis(4-fluorobenzoyl) naphthalene(compound 2) was synthesized via a two-step reaction. 1,4-Naphthalenedicarboxylic acid chloride(compound 1) was prepared by using the acyl chlorization reaction of 1,4-naphthalenedicarboxylic acid with thionyl chloride. The Friedel-Crafts acylation of compound 1 with fluorobenzene afforded compound 2 in a 80% yield. The polycondensation of compound 2 with various bisphenols in tetramethylene sulfone(TMS) in the presence of excess potassium carbonate as a condensation reagent was carried out at 210 ℃ to quantitatively afford the corresponding poly(aryl ether ketone)s(compounds 3_8) containing 1,4-naphthalene moieties. Thermal analyses showed that the polymers have T g values ranging from 496 to 500 K and are thermally stable in air with initial mass loss above 500 ℃. These novel polymers exhibited an excellent solubility in organic solvents including NMP, DMAc, and chloroform, etc. In addition, the glass transition temperatures of these polymers increased and the polymers became insoluble in chloroform after treated at 260 ℃, indicating the occurrence of a thermal crosslinking reaction.

Synthesis and Properties of Poly(aryl ether ketone) Copolymers Containing 2,7-Naphthalene Moieties

Poly（ aryl ether ketone） copolymers containing 2,7-naphthylene and hydroquinone（HQ） moieties with various compositions were prepared by the reaction of 4,4＇-difluorobenzophenone（DFB） 2,7-naphthylene and hydroquinone in the presence of sodium carbonate and potassium carbonate （ 19： 1, mass ratio） in diphenyl sulfone （DPS）. The thermal analysis results of the copolymers show that the glass transition temperatures（Tgs） increase, while the melting temperatures（Tra） and tile 5.0% weight loss temperatures （ Td ） decrease with the increase of the 2,7-naphthalene moieties. For the copolymers synthesized at a molar fraction of 2,7-naphthalene in the difluoro monomers being over 0.30, no peaks corresponding to the cold crystallization temperature and the melting temperature could be detected, indicating that these copolymers are almost amorphous. The crystal structures of the copolymers with a molar fraction of 2,7-naphthalene being less than 0. 30 are rhombic.

Synthesis and Antibacterial Activity of Juglone Derivatives

Nitro and halogen substituted derivatives of the juglone naphthoquinone were synthesized and assayed for their antibacterial activity. 8-Nitrojuglone was obtained as the exclusive product from the direct nitration of juglone with nickel （Ⅱ） nitrate and p-toluenesulphonic acid. In addition, a series of five 8-halojuglone derivatives were synthesized via a solvent-free Friedel-Crafts acylation reaction. One of the acylation reactions afforded an anthraquinone-type derivative as the minor product. The 8-nitrojuglone derivative displayed the most notable activity against S. aureus. However, all of the 8-halojuglone derivatives were found to be less active than juglone against the bacteria assayed.

Solvent-free synthesis of some ethyl arylglyoxylates

An efficient and convenient approach to synthesize of ethyl arylglyoxylates by solvent-free grinding was described. Eight ethyl arylglyoxylates had been synthesized by this method, this method provided several advantages such as little pollution, high yield, good selectivity, and simple workup procedure, their structures were confirmed by IR, ^1HNMR.

A Facile Synthesis of 9,10-Dimethoxybenzo[6,7]- ox-epino[3,4-<i>b</i>]quinolin-13(6<i>H</i>)-one and Its Derivatives

A concise and efficient method for the synthesis of novel 9,10-imethoxybenzo[6,7]oxepino[3,4-b]quinolin13(6H)-one and its derivatives 7a-p has been developed via the intramolecular Friedel-Crafts acylation reactions of 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylic acids 6a-p with polyphosphoric acid (PPA) as catalyst and solvent under mild conditions. The key intermediates 6a-p were prepared through the in situ formation of ethyl 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylates 5a-p followed by hydrolysis with aqueous ethanolic sodium hydroxide solution. The novel synthetic method has the advantages of good yields, easy work-up, and environmentally friendly character, which may provide a novel highly efficient process for making quinoline and related azaheterocycle libraries.

Visible-light induced transition-metal and photosensitizer-free conversion of aldehydes to acyl fluorides under mild conditions

Acyl fluorides are powerful synthons for acylation with wide application in the synthesis of valued compounds,especially peptides.Herein,a practical and catalyst-free method for the synthesis of acyl fluorides from aldehydes via C(sp^(2))-H fluorination is reported.This method enables the conversion of both aliphatic and aromatic aldehydes into acyl fluorides in good to excellent yields by visible-light under mild conditions in the absence of transition-metal and external photosensitizer.A variety of functional groups were well tolerated for this transformation.This green method provides a practical pathway to synthesize acyl fluorides under mild conditions.

Synthetic strategies for piperazine derivatives

As important constitutes in many drugs, piperazine comprised compounds are of great interest for drug design. In this paper, two piperazine-based compounds were synthesized for the first time, with different strategies exploited. For one compound, a highly reactive intermediate of isothiocyanate was constructed to get the desired piperazinecarbothioamide. The synthesis of the other compound was completed sequentially through Friedel-Crafts acylation, coupling reaction and Michael addition. Both synthetic routes have short steps and acceptable yields, and such strategies can be applied to the synthesis of similar oioerazine-containin~ comoounds.