Homogeneous Electrocatalysis of the Trichloromethylphenylcarbinol Production by the Electroreduction of Chloroform and Benzaldehyde Mixed in Dimethylformamide

Galvanostatic electrolysis of a chloroform–benzaldehyde mixture in the cathodic space of a diaphragm cell (Pt cathode, C anode) filled with a 0.1 M Bu₄NBr solution in dimethylformamide yields trichloromethylphenylcarbinol. The benzaldehyde acts as both a prebase (intermediate radical anion of benzaldehyde deprotonates the chloroform) and an electrophilic agent. The interaction between benzaldehyde and the trichloromethyl anion yields an alcoholate, which in turn can deprotonate chloroform. The overall process occurs via a homogeneous-catalysis mechanism. Under certain conditions, the current efficiency for the target product reaches nearly 500%.     

A Facile Solid—phase Synthesis of 3—Carboxycoumarins

3-Carboxycoumsrins were synthesized via the solid phase synthesis conviently. The resin bound cyclic malonic ester reacted with o-methoxy or o-hydroxybenzaldehydes. Then cyclization was processed under H2SO4 to afford the products in excellent purities and yields.     

3-O-甲基槲皮素的合成

以芦丁为原料经苄基化、酸水解、选择性甲基化和氢化脱苄四步反应,合成了3-O-甲基槲皮素,总收率为76%.利用1H NMR和MS对中间体及产物的结构进行了确证.该发现有望为3-取代槲皮素衍生物的合成提供一条捷径.     

A Facile Synthesis of 1(3)-Acylglycerols

A facile route is described for the synthesis of 1(3)-acylgiycerols for the first time through hydroxylation of allyl esters of fatty acids with the novel reagent cety1trimethy1ammonium permanganate in a non-aqueous medium.     

核壳型Alq3@SiO2的一锅法制备

利用8-羟基喹啉铝(Alq3)与三乙胺之间路易斯酸碱相互作用的笼效应,以及正硅酸乙酯(TEOS)在三乙胺碱性条件下水解成二氧化硅的原理,经过正硅酸乙酯投料比例调控,成功通过一锅法在Alq3生成的过程中合成了表面由二氧化硅均匀包覆的核壳结构Alq3@SiO2.紫外-可见吸收光谱和荧光发射光谱表明,合成的Alq3@SiO2很好的保持了Alq3的光学性质.     

A Facile Synthesis of Prumycin

Abstract

Benzyl 2,3-anhydro-4-azido-4-deoxy-α-L-ribopyranoside (7), an intermediate for the synthesis of Prumycin was synthesized in 72% yield in seven steps from D-arabinose. Ammonolysis of 7 followed by N-protection with the benzyloxycarbonyl group gave benzyl 4-azido-2-(benzyloxycarbonyl)amino-2,4-dideoxy-α-L-arabinopyranoside (8), which was easily converted to Prumycin.     

Selective Decarboxylation: A Facile Synthesis of 3-Pyridinecarboxylic Acid Derivative

A convenient synthesis of 5-trifluoromethyl-3-pyridinecarboxylic acid was developed, involving palladium-catalyzed carbonylation, hydrolysis, and decarboxylation. This novel route features inexpensive starting material and easy operations.     

Electroreduction of 3-cyanopyridine

3-Aminomethylpyridine and some of its derivatives are either drug materials or insecticides. A simple electrolytic reduction method for the preparation of 3-aminomethylpyridine dihydrochloride using deposited palladium black over graphite is described. This technique should be generally useful for the preparation of primary amines.     

A New Facile Synthesis of 5-Alkyl-2-Aryl-3H-Pyrazol-3-Ones

The title compounds widely used in construction of pigments and antimaterials are most usually prepared by condensation of arylhydrazines and β-keto esters ^1,2. Although a number of 5-methyl and aryl derivatives have been obtained, other 5-alkyl-3-pyrazolones are rarely mentioned in literature ³ because of the lack of a convenient method to prepare the approperate β-keto esters used in condensation.     

A Convenient Synthesis Of 3-Arylcoumarins From Arylacetonitriles

The condensation of salicylaldehydes with various arylacetonitriles catalyzed by anion-exchange resins such as Amberlite IRA 900, leads to the corresponding 3-arylcoumarins in good yields and selectivity.     

A Facile Synthesis of 3,4-Dialkoxythiophenes

Dialkylation of diethyl 3,4-dihydroxythiophenedicarboxylate followed by ester hydrolysis and acid decarboxylation provides a general route to 3,4-dialkoxythiophenes.     

A Facile Synthesis of 2-Aminonicotinaldehyde

A synthesis of 2-aminonicotinaldehyde (1) which does not require chromatography and is easily scaled up has been developed. Bromination of 2-amino-3-picoline, protected as a phthalimide (4), produced the gem-dibromide (5), which was reacted with Nh₄OH. The imine intermediate (7) was hydrolyzed with acid, producing (1) in a 56% conversion from 4.     

A Facile Synthesis of Benzoxazolyl Cyclopropanes

2′-Benzoxazolyl substituted cyclopropane derivatives were synthesized in the yield of 73-89% from the reaction of telluronium ylides with chalcones.     

A Facile One-Pot Synthesis of Vinpocetine

A one-pot synthesis of vinpocetine from vincamine was established. Lewis acids caused transesterification and/or dehydration of vincamine in EtOH. FeCl₃ catalyzed both transesterification and dehydration while Ti(OEt)₄ selectively catalyzed transesterification.     

手性芳基膦-噁唑啉的简便合成

膦-噁唑啉化合物作为一类“优势配体”,自发现以来就引起化学家们的广泛关注。 现有合成方法存在路线长、收率低、分离困难等问题。 本研究发展了一种合成手性芳基膦-噁唑啉(PHOX)的简单高效方法。 在1-羟基苯并三唑(HOBt)、1-(3-二甲氨基丙基)-3-乙基碳二亚胺盐酸盐(EDCI)作用下,2-(二苯基膦基)苯甲酸与多种光学纯的氨基醇发生缩合反应,高收率获得酰胺基醇类化合物;之后酰胺基醇经三苯基膦/三乙胺/四氯化碳体系处理完成噁唑啉环的构建,以64%86%的总收率得到膦-噁唑啉化合物。 随后,合成的化合物(S)-t-BuPHOX被应用于钯催化β-酮酯的脱羧Tsuji烯丙基化反应,得到了80%的收率和84%的ee值。 该新方法具有原料易得、条件温和、收率高等优点。     

A Facile Synthesis of 11-Dodecynal

A three-step synthesis of 11-dodecynal is described.     

A Facile Synthesis of Pechmann Dyes

A facile synthesis of Pechmann dyes has been accomplished by the reaction of substituted N‐phenacyl‐4‐dimethylaminopyridinium halides with dimethyl maleate in the presence of DBU. Based on a related 4‐DMAP elimination product and an isolated monolactone intermediate a reaction mechanism has been proposed. The scope of this synthetic method is determined by the availability of α‐haloaroyl or heteroaroyl derivatives. DBU=1,8‐diazabicycloundec‐7‐ene, DMAP=4‐dimethylaminopyridine.     

A Facile Formal Synthesis of Volicitin

A short and concise synthesis of volicitin is presented. The synthesis is based on repeated chemoselective copper salt cross coupling reactions of alkynes and propargylic halides.     

A Facile Synthesis of Various Butenolides

The synthesis of α'-acyloxy-α,β-unsaturated cyclic ketones from the corresponding α,β-unsaturated cyclic ketones by using manganese (III) acetate in combination with 2-chloropropionic acid followed by subsequent Arbuzov and intramolecular Horner-Emmons cyclization reactions provided a convenient synthetic pathway to various butenolides 4a-d.