"One-pot" two-step synthesis of aryl sulfur compounds by photoinduced reactions of thiourea anion with aryl halides

[reaction: see text]. The photoinduced reactions of aryl halides with the thiourea anion afford arene thiolate ions in DMSO. These species without isolation, and by a subsequent aliphatic nucleophilic substitution, S(RN)1 reaction, oxidation, or protonation, yield aryl methyl sulfides, diaryl sulfides, diaryl disulfides, and aryl thiols with good yields (50-80%). This is a simple and convenient approach which involves the use of the commercially available and inexpensive thiourea in a "one-pot" two-step process for the synthesis of aromatic sulfur compounds.     

Oligomerization of higher olefins and alkylation of toluene catalyzed by 2-[hydroxy(diaryl)methyl]-8-hydroxyquinoline oxovanadium(v) complexes

Russian Chemical Bulletin - New oxovanadium(V) complexes with 2-[hydroxy(diaryl)methyl]-8-hydroxyquinoline ligands were synthesized. These compounds were found to be efficient tandem catalysts of...     

New 1,4‐Diaryl [1,2,3]‐Triazole Liquid Crystals Using a Click Reaction

New nonlinear compounds containing 1,4‐diaryl‐[1,2,3]‐triazole were prepared using a straightforward and efficient method for the regioselective synthesis of [1,2,3]‐triazoles. The methodology consists of a Cu(I)‐catalyzed 1,3‐dipolar cycloaddition of aryl azides to terminal arylacetylenes (click reaction). All compounds exhibited liquid‐crystalline profile.     

The use of aminoiminomethanesulfinic acid (thiourea dioxide) under phase transfer conditions for generating organochalcogenate anions. Synthesis of sulfides,selenides and tellurides

A procedure is described which allows for the in situ synthesis of arylalkyl, diaryl and dialkylchalcogenides under phase transfer conditions starting from the corresponding diorganodichalcognides. The dichalcogenides are reduced by aminoiminomethanesulfinic acid (thiourea dioxide) in alkaline medium and catalyzed by a quaternary ammonium salt. The reduction proceeds easily for diaryl disulfides and diaryl diselenides at a sodium hydroxide concentration of 13%; diaryl ditellurides require a 50% sodium hydroxide solution to give the aryl tellurolate anion. The dialkyl diselenides and dialkyl ditellurides are more difficult to reduce. The intermediate arylthiolates and arylselenolates are quenched by alkyl and activated aryl halides to give the corresponding sulfides and selenides in high yield (77–97%). The aryltellurolates react with alkyl halides giving the aryl alkyl tellurides in 81–96% yield. The procedure could not be successfully used for the synthesis of dialkylselenides and dialkyl tellurides; low yields and mixture of products were formed.     

Spiro‐heterocycles from substituted pyridines,pyrans and thiopyrans

A new class of spiro‐pyrimidines, pyrazoles and isoxazoles are prepared by nucleophilic reaction of 3,5‐diaroyl‐2,6‐diaryl‐piperidine‐4,4‐dicarbonitrile (1), 3,5‐diaroyl‐2,6‐diaryl‐tetrahydropyran‐4,4‐dicarbonitrile (2) and 3,5‐diaroyl‐2,6‐diaryl‐tetrahydrothiopyran‐4,4‐dicarbonitrile (3) with urea, N,N'‐dimethyl urea, thiourea, hydrazine hydrate and hydroxylamine hydrochloride.     

二芳基氨(硼)-π-碳硼烷三元化合物的二阶非线性光学性质的理论研究

采用密度泛函理论(DFT)方法对二芳基氨(硼)-π-十二顶点碳硼烷三元化合物的结构及二阶非线性光学(NLO)性质进行计算.结果表明,化合物共轭桥长度及二芳基氨(硼)对化合物偶极矩的影响较小.随着分子共轭桥的增长,分子的电子空间范围R2增大,从而使极化率和第一超极化率增大.通过分析化合物的电子光谱和对应的分子轨道组成可知,分子中电荷转移主要发生在二芳基氨(硼)和π-桥之间,碳硼烷的贡献较少.二芳基氨和二芳基硼的供电子能力差异可以调节分子的二阶NLO响应.     

Some studies on the photo-initiated cationic polymerisation of epoxides

Several triarylsulphonium and diaryliodonium compounds have been synthesised. Alkylarylsulphonium compounds were obtained by alkylating diaryl sulphides with trialkyloxonium salts and by reaction of diaryl sulphides with alkyl halides in the presence of silver tetrafluoroborate. Photolysis of the sulphonium salts in methanol gave diaryl sulphides and, in the case of triarylsulphonium compounds, the appropriate aromatic hydrocarbon and its methyl ether. Diaryliodonium tetrafluoroborates and pentafluorophosphates gave aryl fluorides, biaryls and aromatic hydrocarbons. The decomposition of the salts is suggested as occurring via both free radical and ionic pathways. The ability of the compounds to sensitise the polymerisation of epoxy resins was found to be dependent upon the counterion (hexafluorophosphates being more efficient than tetrafluoroborates) and upon the structure of the cation. Sensitised cationic initiated polymerisation was also investigated and it was found that both excited singlet state and triplet state sensitisers were effective.     

Enantio- and diastereoselective Michael reaction of 1,3-dicarbonyl compounds to nitroolefins catalyzed by a bifunctional thiourea

We synthesized a new class of bifunctional catalysts bearing a thiourea moiety and an amino group on a chiral scaffold. Among them, thiourea 1e bearing 3,5-bis(trifluoromethyl)benzene and dimethylamino groups was revealed to be highly efficient for the asymmetric Michael reaction of 1,3-dicarbonyl compounds to nitroolefins. Furthermore, we have developed a new synthetic route for (R)-(-)-baclofen and a chiral quaternary carbon center with high enantioselectivity by Michael reaction. In these reactions, we assumed that a thiourea moiety and an amino group of the catalyst activates a nitroolefin and a 1,3-dicarbonyl compound, respectively, to afford the Michael adduct with high enantio- and diastereoselectivity.     

Ligand‐free copper‐catalysed direct synthesis of diaryl sulfides and diaryl disulfides in wet poly(ethylene glycol)

An improved protocol has been developed for the one‐pot CuI‐catalysed preparation of symmetric diaryl sulfides from their available aryl halides in the presence of thiourea as sulfur transfer agent and in the absence of both ligand and organic solvent. This catalytic system was also used for the high‐yielding preparation of diaryl disulfides in the presence of C₂Cl₆ as oxidant.     

An Efficient Solid-State Synthesis of N-Aryl-2-phenyldiazenecarboxamides

The subject of organic solid-state synthesis is a fascinating one. It has many advantages such as high efficiency and selectivity, easy separation and purification, mild reaction conditions, and environmental acceptability1. In recent years, this method has been widely used in a variety of organic reactions including substitution2, condensation3, oxidation-reduction4, rearrangement5 and elimination6. However, the solid state reaction using K3Fe(CN)6/KOH to oxidize substituted semicarbazides…     

2,6‐Diaryl‐4,4‐disubstituted 1,4‐dihydropyridines: Source for spiro heterocycles

Novel spiro heterocycles ( 5–12 ) were obtained by the cyclocondensation of 2,6‐diaryl‐4,4‐dimethoxycarbonyl‐/4‐cyano‐4‐ethoxycarbonyl‐1,4‐dihydropyridines( 3/4 ) with hydrazine hydrate, hydroxylamine hydrochloride, urea, and thiourea. All the compounds were characterized by IR, ¹H NMR, and ¹³C NMR spectral data.© 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:513–517, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10183     

Synthesis of New Pyrrolo Heterocycles (I): Novel Synthesis of Pyrano[2,3‐c]pyrrole,Isoindoline, Pyrrolo[3,4‐b]pyridine,and Pyrrolo[3,4‐d]pyrimidine Derivatives

Michael addition of 1,5‐diaryl‐2,3‐dioxopyrrolidine derivatives with α‐cyanocinnamonitriles and ethyl α‐cyanocinnamates afforded 4H‐pyrano[2,3‐c]pyrrole derivatives in the presence of sodium ethoxide. Under the same reaction condition, the ylidenes of 1,5‐diaryl‐2,3‐dioxopyrrolidine were reacted with malononitrile or ethyl cyanoacetate to give isoindole derivatives; however, pyrrolo[3,4‐b]pyridine derivatives were formed when cyanoacetamide was used. Moreover, pyrrolo[3,4‐d]pyrimidine derivatives were synthesized by treating 4‐benzylidene‐1,5‐diphenyl‐2,3‐dioxopyrrolidine with urea and/or thiourea under basic conditions. The structures of all the new synthesized compounds were confirmed by elemental analysis, IR and NMR spectra.     

Design,Synthesis and Antiproliferative Activities of Diaryl Thiourea Derivatives as Anticancer Agents

Two new series of diaryl thiourea containing sorafenib derivatives 9a – 9t were designed and synthesized, and their antiproliferative activities against PC‐3, HCT116 and MDA‐MB‐231 cell lines were evaluated. All compounds generally showed antiproliferative activity to PC‐3 cells, most of the analogs exhibited potent antiproliferative activity to HCT116 cells, and compounds 9e , 9f , 9o and 9p demonstrated inhibitory activities against all three cell lines. The structures of all the newly synthesized compounds were determined by ¹H NMR, ¹³C NMR and HRMS.     

Reduction of Organoselenium and Tellurium Halides and Oxides with Thiourea Dioxide

Aryltellurium trihalides, arylselenium trihalides, organyltellurium and selenium dichlorides and organylselenoxides and telluroxides were reduced in high yield to the corresponding diaryl ditellurides and selenides with thiourea dioxide in a two phase system.     

Synthesis of functionalized diaryl selenides by the first [3+3] cyclocondensations of 1,3-bis(silyloxy)-1,3-butadienes with organoselenium compounds

Functionalized diaryl selenides were prepared by the first [3+3] cyclizations of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with organoselenium compounds (i.e., 2-(phenylselanyl)-3-silyloxy-3-en-1-ones).     

Inhibition of peroxynitrite- and peroxidase-mediated protein tyrosine nitration by imidazole-based thiourea and selenourea derivatives

In the present study, the synthesis and characterization of a series of N-methylimidazole-based thiourea and selenourea derivatives are described. The new compounds were also studied for their ability to inhibit peroxynitrite (PN)- and peroxidase-mediated nitration of protein tyrosine residues. It has been observed that the selenourea derivatives are more efficient than the thiourea-based compounds in the inhibition of protein nitration. The higher activity of selenoureas as compared to that of the corresponding thioureas can be ascribed to the zwitterionic nature of the selenourea moiety. Single crystal X-ray diffraction studies on some of the thiourea and selenourea derivatives reveal that the C=S bonds in thioureas possess more of double bond character than the C=Se bonds in the corresponding selenoureas. Therefore, the selenium compounds can react with PN or hydrogen peroxide much faster than their sulfur analogues. The reactions of thiourea and selenourea derivatives with PN or hydrogen peroxide produce the corresponding sulfinic or seleninic acid derivatives, which upon elimination of sulfurous/selenous acids produce the corresponding N-methylimdazole derivatives.     

Nonracemic diarylmethanols from CuH-catalyzed hydrosilylation of diaryl ketones

An efficient method for the synthesis of nonracemic diarylmethanols has been developed. The use of ( R)-(-)-(DTBM-SEGPHOS)CuH effects highly enantioselective 1,2-hydrosilylation of prochiral diaryl ketones.     

An efficient MnCl2‐catalyzed tandem acylation‐cross‐coupling reaction of o‐halobenzoyl chloride with diorganyl magnesium compounds

An efficient tandem cross‐coupling reaction of o‐chlorobenzoyl chloride with dialkyl and diaryl magnesium compounds in the presence of manganese (II) chloride was developed, which proceeds in good yield under mild conditions. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis 1-acyl-3-(2'-aminophenyl) thioureas as anti-intestinal nematode prodrugs

A series of 1-acyl-3-(2'-aminophenyl) thiourea derivatives were designed and synthesized. The structures of all the newly synthesized compounds were identified by IR, elemental analysis, 1H-NMR and 13C-NMR. Their anti-intestinal nematode activities against Nippostrongylus brazilliensis were evaluated in rats by an oral route. Among these compounds, at concentrations of 10 mg/kg of rat, compound (1-(2'-furanyl)acyl-3- (2'-aminophenyl) thiourea) produced the highest activity with 89.4% deparasitization. The present work suggests that 1-acyl-3-(2'-aminophenyl) thiourea derivatives may become useful lead compounds for anti-intestinal nematode treatment.     

Efficient Synthesis of β‐Alkyl/Arylsulfanyl Carbonyl Compounds by In‐TMSCl‐Promoted Cleavage of Dialkyl/Diaryl Disulfides and Subsequent Michael Addition

A convenient and efficient procedure for the synthesis of β‐alkyl/arylsulfanyl carbonyl compounds has been developed by a simple one‐pot reaction of dialkyl/diaryl sulfides with α,β‐unsaturated aldehydes, ketones, carboxylic esters, and nitriles in presence of indium and trimethylsilyl chloride under sonication.