A facile electrochemical method for the synthesis of new sulfonamide derivatives of potential biological significance

The electrochemical synthesis of some new sulfonamide derivatives was carried out via the electrochemical oxidation of 2,3-dihydrophthalazine-l,4-dione （1） in the presence of arylsulfinic acids （2a and 2b） as nucleophiles. The results show that, the electrogenerated phthalazine-l,4-dione （lox） participates in a Michael type addition reaction with 2a or 2b and via an EC mechanism to produce the corresponding sulfonamide derivatives. This method provides a one-pot procedure for the synthesis of new sulfonamide derivatives of potential biological significance in good yields without using toxic reagents at a carbon electrode in an environmentally friendly manner.     

A facile stereoselective synthesis of (E)-α-silylvinylstannanes via hydromagnesiation of alkynylsilanes

(E)-α-Silylvinylstannanes have been synthesized by the hydromagnesiation reaction of alkynylsilanes, followed by the reaction with trialkylstannyl chlorides. (E)-α-Silylvinylstannanes can undergo the cross-coupling reaction with aryl iodides in the presence of a catalytic amounts of Pd(PPh₃)₄ and CuI to afford (Z)-1,2-disubstituted vinylsilanes in good yields.     

A facile synthesis of 2-(N-alkylamino)-pyrimidin-4-one derivatives

Substituted 2-(N-alkylamino)-pyrimidin-4-ones were synthesized from N-alkyl β-amino acid esters starting with guanidinylation using Pbf-activated thiourea. The six-membered pyrimidinones were obtained in good yields via intramolecular cyclization during TFA cleavage of the Pbf protecting group.     

A facile stereospecific synthesis of （Z）-2-sulfonyl-substituted 1,3-enynes via Sonogashira coupling of （E）-α-iodovinyl sulfones with 1-alkynes

(E)-a-Iodovinyl sulfones 1 underwent the Sonogashira coupling reactions with terminal alkynes 2 in piperidine at room temperature in the presence of 5 mol% of Pd(PPh3)4 and 10 mol% of CuI to stereospecifically afford the corresponding (Z)-2- sulfonyl-substituted 1,3-enynes 3 in high yields.     

Catalyst-free synthesis of (E)-2-alkenylquinoline derivatives via C(sp3)-H functionalization of 2-methylquinolines

This Letter described a facile approach to synthesize (E)-2-alkenylquinoline derivatives via C(sp³)-H functionalization of 2-methylquinolines under catalyst-free conditions. A variety of electronically and sterically diverse 2-methyl quinoline and aromatic aldehydes were well tolerated.     

A facile synthesis of per (poly )fluoroalkyl substituted α-amino acid derivatives

Initiated by CrCl3/Fe redox couple, per(poly)fluoroalkyl iodides added to methyl a-acetylamino acrylate, giving B-per(poly)fluoroalkyl a-amino acid derivatives in good yields.     

A new and efficient method for the synthesis of 3-(2-nitrophenyl)pyruvic acid derivatives and indoles based on the Reissert reaction

The formation of 3-(2-nitrophenyl)pyruvic acid and its amide and ester derivatives – key compounds for the Reissert indole synthesis – was achieved under various reaction conditions via the acid catalyzed hydrolysis of 5-(2-nitrobenzyliden)-2,2-dimethyl-1,3-oxazolidin-4-one, which is readily available from 3-(2-nitrophenyl)oxirane-2-carboxamide. A new and highly efficient method for the synthesis of indole-2-carboxylic acid derivatives via the intramolecular reductive cyclization of o-nitrophenylpyruvic acid and its amide and ester derivatives was developed using Na₂S₂O₄ in dioxane/water at reflux.     

A new 1H-pyridin-(2E)-ylidene ruthenium complex as sensitizer for a dye-sensitized solar cell

The new heteroleptic ruthenium(II) complex containing a 1H-pyridin-(2E)-ylidene (PYE) ligand was synthesized and characterized using UV/Vis, FTIR, and NMR spectroscopies, mass spectrometry, elemental analysis, and cyclic voltammetry. The photovoltaic performance of the ruthenium complex as a charge transfer photosensitizer in nc-titanium dioxide based dye-sensitized solar cell was studied and compared with cis-bis(isothiocyanato)(2,2′-bipyridyl-4,4′-dicarboxylato)(2,2′-bipyridyl-4,4′-di-nonyl)ruthenium(II) (Z907) under standard AM 1.5 sunlight. The complex CS90 gave a photocurrent density of 1.80?mA?cm^?2, 400?mV open-circuit potential, and 0.58 fill factor yielding an efficiency of 0.42% where the reference Z907 yielded an efficiency of 4.12%. The decrease in conversion efficiency observed for CS90 is attributed to a steric interaction between PYE and the TiO₂ surface that prevents optimum binding and also restricts ligand dynamics that are associated with oxidation state changes.     

手性位移试剂Eu(dcm)~3的一个改进合成方法

我们对H(dcm)的Whitesides合成路线的关键步骤龙脑酰甲烷的合成和缩合反应进行了重要的改进。     

A facile synthesis of novel unsymmetrical N-(4-oxo-2-phenyl-3(4H)-quinazolinoyl)-N-(aryl)acetamidines

<正>A series of novel unsymmetrical N-(4-oxo-2-phenyl-3(4H)-quinazolinoyl)-N-(aryl) acetamidines was synthesized by reacting ethyl(1H)-N-(4-oxo-2-phenylquinazolin-3(4H)-y1)ethanimidoate(2) and suitable reactive aromatic amines.Structures' determination of the synthesized compounds was carried out using spectroscopic techniques including IR,~1H NMR,and mass spectrometry. Structural effects on reactivity were also studied.     

A facile and efficient method for the synthesis of N-substituted isoindolin-1-one derivatives under Pd(OAc)2/HCOOH system

A facile and efficient method for the synthesis of N-substituted isoindolin-1-one derivatives from 2-formylbenzoic acid and amine under Pd(OAc)₂/HCOOH system has been described. The whole process is carried out in ligand-free conditions and furnished the desired products by reductive intramolecular cyclization. Furthermore, this procedure is applied successfully for the modification of natural products, such as vindoline and estrone.     

The synthesis and characterization of a new (E,E)-dioxime containing 20-membered tetraazadioxa macrocyclic moieties and its mononuclear complexes

A new (E,E)-dioxime, (2Z,3Z)-9,20-bis[(4-methylphenyl)sulfonyl]-1,4,7,8,9,10,11,12,14,15,17, 18,19,20,21,22-hexadecahydro-13,16-ethano[1,4,7,11,14,18]dioxatetraazacycloicosino[2,3-g] quinoxaline-2,3-dione dioxime (6) (H₂L) has been synthesized by reacting cyanogen-di-N-oxide (5) with 4,15-bis[(4-methylphenyl)sulfonyl]-2,3,4,5,6,7,9,10,12,13,14,15,16,17-tetradecahydro-8,11-ethano-1,18,4,8,11,15-benzodioxatetraazacycloicosine-20,21-diamine (4). Mononuclear complexes (7) and (8) of this ligand have been synthesized by reacting the vic-dioxime (H₂L) with NiCl₂.6H₂O and CoCl₂.6H₂O respectively. The BF₂⁺ capped Ni(II) and Co(III) complexes (9) and (10) of the dioxime have been synthesized from (7) and (8), respectively. The new compounds were characterized by a combination of elemental analysis, ¹H- and ¹³C-NMR, IR. and MS. spectral data.     

A new synthesis of pyrrolidines via imino-aldol reaction of (2-trimethylsilylmethyl)cyclopropyl ketones with imines

A new synthesis of 2,3,5-trisubstituted pyrrolidines from the imino-aldols formed from Lewis acid-mediated reactions of (2-trimethylsilylmethyl)cyclopropyl ketones with benzylimines is described. The ring closure of the imino-aldols formed from the benzylimines of 2-chloro-, 2-fluoro-, and 2-trifluoromethylbenzaldehydes proceeds with predominantly 2,5-anti selectivity to generate the corresponding pyrrolidines in moderate yields.     

A new method for the synthesis of 3-aryl-6-(2-pyrrolyl)pyridazines

A new method for the synthesis of 3-halo-6-(N-tosyl-2-pyrrolyl)pyridazine 7 was developed. Suzuki cross-coupling reactions of 7 with arylboronic acids and in situ de-tosylation gave a variety of novel 3-aryl-6-(2-pyrrolyl)pyridazines. It found that protection of the pyrrolyl moiety was necessary for efficient coupling reaction.     

A facile and environmental friendly strategy for the synthesis of N-methoxyquinolin-2(1H)-ones

A facile and environmental friendly protocol for the construction of N-methoxyquinolin-2(1H)-ones was developed using a stable and easily available N-methoxyquinoline-1-ium tetrafluoroborate as starting material. Due to the mild reaction conditions, a broad range of N-methoxyquinolin-2(1H)-ones with different functional groups have been prepared in reasonable yields.     

A new approach to the facile synthesis of 2-substituted-quinazolin-4(3H)-ones

A new approach to the facile synthesis of 2-substituted-quinazolin-4(3H)-ones and its derivatives using the condensation reaction of substituted 2-aminobenzamide and orthoesters is reported.     

One-Pot Synthesis of 1-(E)-Phenylethenyl-1,2,3-Triazoles by Sequential Click-Elimination Reaction from 2-Azido-1-Phenyl-1-(Phenylseleno)Ethane

Abstract

A new convenient one-pot, two-step procedure involving sequential click chemistry and oxidation-elimination reaction for the preparation of 1,4-disubstituted 1,2,3-triazoles bearing 1-(E)-phenylethenyl group from 2-azido-1-phenyl-1-(phenylseleno)ethane is described. The prominent features of this protocol are mild reaction conditions, operational simplicity, and good to high yields of products, as well as avoidance of the isolation of the selenated intermediate.

Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional figures.     

A new method for synthesis of n-(3-acyloxypropyl)-substituted six- to thirteen-membered alkan-n-olides

A new method for the synthesis of n-(3-acyloxypropyl)-substituted six- to thirteen-membered alkan-n-olides was developed. The method is based on the H₂SO₄-catalyzed reactions of oxabicycloalkenes, obtained from 2-(3-acetoxypropyl)cycloalkanes, with H₂O₂ and formic or acetic acid. The method includes the subsequent transformations of oxabicycloalkenes into bicyclic hydroperoxides, peroxy ethers, and, at the final stage, into target lactones formed in 56—71% yields. These transformations are carried as a one-pot reaction.     

A convenient method for the preparation of mono- and bis-substituted photochromic bis(benzothienyl)perfluorocyclopentenes via regioselective Friedel-Crafts acylation

The regioselective Friedel-Crafts acylation of 1,2-bis(2-methylbenzo[b]thien-3-yl)hexafluorocyclopentene was developed. Depending on the reaction conditions, mono- or bis(bromoacetyl) derivatives are formed as single products in good yields. Further heterocyclizations involving α-bromoketone moieties gave a series of new photochromic compounds.