Synthesis of 1-(alkylamino)- and 1-(dialkylamino)benzimidazoline-2-thiones

Unlike 1-aminobenzimidazoles, 1-alkylaminobenzimidazoles are thiolated on fusing with sulfur without elimination of theN-amino group, yielding the previously unknown 1-(alkylamino)benzimidazoline-2-thiones. These compounds can be more conveniently obtained on a preparative scale by thiolation of 1-alkylacetamidobenzimidazoles with subsequent hydrolytic elimination of the acetyl group. When 1-(dialkylamino)benzimidazoles are fused with sulfur, they are converted into 1-(dialkylamino)benzimidazoline-2-thiones. By alkylation of 1-(methylamino)- and 1-(diethylamino)benzimidazoline-2-thiones with methyl iodide in alkaline media the corresponding 2-(methylthio)benzimidazoles were prepared.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2231–2235, November, 1995.The authors are grateful to the Contest Center of Basic Natural Science at St. Petersburg University for financial support of this study.     

Synthesis of ansa -zirconocenes based on 2-(phenylethynyl)-1 H -indene. The crystal and molecular structure of the complex [μ-CH2CH2(η5-2-PhC≡CInd)2]ZrCl2 (Ind is inden-1-yl)

Alkynyl-substituted indene was first used as a ligand for the synthesis of transition metal complexes. ansa-Zirconocenes containing ethylene and dimethylsilylene bridges were synthesized starting from 2-(phenylethynyl)-1H-indene. The structure of the former compound was established by X-ray diffraction. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 68–73, January, 2007.     

The reaction of chloromagnesium bis(2,3,5,6-tetrachlorophenyl)copper with butyllithium

Chloromagnesium bis(2,3,5,6-tetrachlorophenyl)copper, prepared from two equivalents of 2,3,5,6-tetrachlorophenylmagnesium chloride and one equivalent of copper(I) chloride inTHF, reacts with one equivalent of butyllithium at –78°C to give, subsequent to derivatisation with chlorotrimethylsilane and then with acetyl chloride, (1-acetyl-2,3,5,6-tetrachlorophenyl)trimethylsilane (20%), 1-(trimethylsilyl)-2,3,5,6-tetrachlorobenzene (17%) and 1-acetyl-2,3,5,6-tetrachlorobenzene (34%) along with some trace products. The formation of these products is explained on the basis of the intermediate formation of chloromagnesium bis(1-lithio-2,3,5,6-tetrachlorophenyl)copper, a functionalised cuprate reagent.

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Die Reaktion von Chlormagnesium-bis(2,3,5,6-tetrachlorphenyl) kupfer mit Butyllithium

Zusammenfassung Chlormagnesium-bis(2,3,5,6-tetrachlorphenyl)kupfer, das aus zwei Äquivalenten 2,3,5,6-tetrachlorphenylmagnesiumchlorid und einem Äquivalent Kupfer(I)chlorid inTHF hergestellt wurde, ergab mit einem Äquivalent Butyllithium bei — 78 °C nach Derivatisierung mit Chlortrimethylsilan und dann mit Acetylchlorid folgende Produkte: (1-Acetyl-2,3,5,6-tetrachlorphenyl)trimethylsilan (20%), 1-(Trimethylsilyl)-2,3,5,6-tetrachlorbenzol (17%) und 1-Acetyl-2,3,5,6-tetrachlorbenzol (34%) neben einigen weiteren Produkten in Spuren. Die Bildung der genannten Produkte wird mit Chlormagnesium-bis(1-lithio2,3,5,6-tetrachlorphenyl)kupfer, einem funktionalisierten Cuprat-Reagens, als intermediär gebildeter Verbindung erklärt.

     

Synthesis of propyl O-(α-L-rhamnopyranosyl)-(1→3)-[2,4-di-O-(2s-methylbutyryl)-α-L-rhamnopyranosyl]-(1→2)=(3-O-acetyl-β-D-glucopyranosyl)-(1→2)-βp-D-fucopyranoside,the tetrasaccharide moiety of Tricolorin A

Propyl O-(α-L-rhamnopyranosyl)-(1→3)-[2,4di-O-(2s-methylbutyryl)-α-L-rhamnopyranosyl]-(1→2)-(3-O-acetyl-β-glucopyranosyl)-(1→2)-β-D-fucopyranoside (1), the tetrasaccharide moiety of Ricolorin A, was synthesized in total 23 steps with a longest linear sequence of 10 steps, and overall yield of 3.7% from D-Glucose. The isomerization of the dioxolane-type benzylidene in the prance of NIS/AgOTf was observed. Tetrasaccharide 1 exhibited no activity against the cultured P388 cell as Tricolorin A did.     

Improved synthesis of bis[p-(phenylethynyl)phenyl]hetarylenes

Bis[p-(phenylethynyl)phenyl]hetarylenes were synthesized in high yields by an improved method using cross-coupling between phenylacetylene and 4,4′-dibromobenzil followed by condensation of the 4,4′-di(phenylethynyl)benzil obtained with eithero-phenylenediamine and 3,4-diaminobenzoic acid or with benzaldehyde andp-nitrobenzaldehyde in the presence of ammonium acetate. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1889–1890, October, 1997.     

Preparation of Isoquinolin-(2(1H)-yl)but-2-enedioate Derivatives

One-pot, three-component reactions of isoquinoline, dimethyl/diethyl acetylenedicarboxylate, and indole, carbazole, pyrazole, or imidazole gave dimethyl/diethyl 2-(1-(1H-indol-1-yl)isoquinolin-2(1H)-yl)but-2-enedioate, dimethyl/diethyl 2-(1-(9H-carbazol-9-yl)isoquinolin-2(1H)-yl)but-2-enedioate, dimethyl 2-(1-(1H-pyrazol-1-yl)isoquinolin-2(1H)-yl)but-2-enedioate, or dimethyl 2-(1-(1H-imidazol-1-yl)isoquinolin-2(1H)-yl)but-2-enedioate respectively in good to excellent yields.     

1-(1-Adamantyl)diaziridine

The reaction of 1-aminoadamantane with CH₂O and H₂NOSO₃H in the presence of K₂CO₃ under phase-transfer conditions leads to hitherto unknown 1-(1-adamantyl)diaziridine and (1-adamantyl)aminoacetonitrile, characterized by spectral data. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 861–862, April, 1997.     

Synthesis of conjugated 2,7-bis(trimethylsilylethynyl)-(phenylethynyl)nfluoren-9-one and 9-(p-methoxyphenyl)-9-methyl derivatives: optical properties

2,7-Substituted 9-fluorenones and 9,9-disubstituted fluorene have been synthesized and their fluorescence properties analyzed. The synthesis of conjugated 2,7-bis(trimethylsilylethynyl)-(phenylethynyl)_nfluoren-9-one (or the 9-(p-methoxyphenyl)-9-methyl) structures was carried out by the heterocoupling reaction between the 2,7-di(halo)fluoren-9-one (or 2,7-dibromo-9-(p-methoxyphenyl)-9-methylfluorene) and p-trimethylsilylethynyl(phenylethynyl)_n (n=1,2), catalyzed by the dichloro bis(triphenylphosphine)palladium and cuprous iodide system, in a divergent synthesis.The π-extended conjugated compounds exhibit fluorescence radiation emission (blue light-emitting), with important quantum yield for the 9-(p-methoxyphenyl)-9-methyl-2,7-bis(trimethylsilylethynyl)-(phenylethynyl)_nfluorenes which increases with the conjugation.     

Synthesis of new bis[p-(phenylethynyl)phenyl]hetarylenes and bis[p-(phenylglyoxalyl)phenyl]hetarylenes

A series of new bis[p-(phenylethynyi)phenyl]hetarylenes was obtained by cross-coupling between heteroaromatic dibromides and phenylacetylene catalyzed by phosphine complexes of palladium in the presence of Cul and an organic base. Bis[p-(phenylethynyl)phe-nyl]hetarylenes were oxidized to the corresponding bis[p-(phenylglyoxalyl)phenylihetarylenes using the I₂-DMSO system.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2359–2361, September, 1996.     

Synthesis and characterization of polymeric triphenyltin and cyclotetrameric tricyclohexyltin 2-(1H-imidazol-1-yl)acetates

The reaction of 2-(1H-imidazol-1-yl)acetic acid with (Ph₃Sn)₂O or Cy₃SnOH (Cy?=?cyclohexyl) yields triphenyltin 2-(1H-imidazol-1-yl)acetate (1) and tricyclohexyltin 2-(1H-imidazol-1-yl)acetate (2), respectively. 2-(1H-imidazol-1-yl)acetates in these two complexes show remarkably different coordination modes. Complex 1 forms a polymeric chain structure through intermolecular Sn–N interactions, while 2 displays a 28-membered macrocyclic tetranuclear structure by the assembly of Sn–N coordination bonds.     

Syntheses,crystal structures and properties of two cadmium coordination polymers containing bis (2-methylimidazol-1-yl)methane(2-mBIM) and bis (imidazol-1-yl)methane (BIM) ligands

Coordination polymers, {[Cd(2-mBIM)₃](ClO₄)₂} _n (1) and [Cd(BIM)₂(NO₃)₂] _n (2), have been prepared from the reaction of bis(2-methylimidazol-1-yl)methane(2-mBIM) with Cd(ClO₄)₂ and bis(imidazol-1-yl)methane (BIM) with Cd(NO₃)₂ in ethanol and water, respectively. Their structures were characterized by single crystal X-ray diffraction and IR spectroscopy. Compound 1 crystallizes in the rhombohedral space group R-3c with a = b = 12.3617(5) Å, c = 38.896(3) Å, γ = 120°, V = 5147.5(5) ų, z = 6. The Cd^II occupies a crystallographic inversion center and is coordinated by six N atoms from six distinct 2-mBIM ligands to form a slightly distorted octahedral geometry. Each 2-mBIM is coordinated to two Cd^II cations, linking alternatively four Cd^II cations, resulting in a 32-membered M₄L₄ macrometallacycle. Compound 2 crystallizes in the monoclinic space group C2/m with a = 14.400(3) Å, b = 9.3894(18) Å, c = 8.6926(17) Å, β = 123.499(2)°, V = 980.1(3) ų, z = 2. The Cd coordinates to four nitrogen atoms from four different BIM and two nitrates to form a slightly distorted octahedral geometry. The BIM ligands bridge to form a 1-D infinite double-bridged chain structure with 16-membered M₂L₂ macrometallacyclic structural units.     

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.     

有机相酶催化拆分制备(S)-2-氯-1-(2-噻吩)-乙醇

首次在有机相中对酶催化条件下的2-氯-1-(2-噻吩)-乙醇的反应进行了研究. 通过对不同来源酶的筛选, 找到了Novozym 435和Alcaligenes sp两种选择性较好的酶, 它们均对该反应具有较高的选择性和较快的反应速度, 在此基础上进一步通过对溶剂、温度、摇床转速以及酶用量的筛选, 确定了能够有效拆分2-氯-1-(2-噻吩)-乙醇的较佳反应条件. 当温度35 ℃, 酶量10 mg/mL, 反应72.5 h, 产物的ee值为98.5%时收率为48.6%.     

Facile synthesis of 1-(arylimino)naphthalen-2(1H)-ones from anilines and 2-naphthols promoted by NaBr/K2S2O8/CAN

An efficient method has been developed for the synthesis of 1-(arylimino)naphthalen-2(1H)-ones through the cascade reaction of anilines and 2-naphthols promoted by NaBr/K₂S₂O₈/Ce(NH₄)₂(NO₃)₆. Using this protocol, a series of 1-(arylimino)naphthalen-2(1H)-ones was obtained in good to excellent yields (17 examples, 70–92% yields). The reactions may proceed through the following steps: bromination of 2-naphthols by in-situ-generated bromine from NaBr and K₂S₂O₈ to afford 1-bromonaphthalen-2-ols, coupling of 1-bromonaphthalen-2-ols with anilines to afford the corresponding amines, and subsequent oxidation of the amines into the products by Ce(NH₄)₂(NO₃)_6. These newly obtained α-imine ketones have great potentials for synthesis of special optical materials bearing naphthalene moiety.     

Dipotassium Hydrogen Phosphate Powder Catalyzed Stereoselective O-Vinylation of 1-(2-Hydroxy-1-naphthyl)-1-ethanone

Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates, by 1-(2-hydroxy-1-naphtyl)-1-ethanone leads to vinyltriphenylphosphonium salts, which undergo a Michael addition reaction with a conjugate base to produce corresponding stabilized phosphorus ylides. Dipotassium hydrogen phosphate powder was found to catalyze the conversion of stabilized phosphorus ylides to dialkyl (E, Z)-2-(1-acetyl-2-naphthyl)-2-butenedioates under thermal and microwave conditions in a solventless system.     

Asymmetric Reduction Using Lithium Aluminum Hydride Modified with Chiral Ligands Prepared from (1R)-(-)-β-Pinene

The reduction of prochiral ketones using chiral reducing reagents, prepared from lithium aluminum hydride and (-)-(1R, 2S, 3S, 5R)-10-anilinopinanediol (5) and (-)-(1R, 2S, 3S, 5R)-10-N-methylanilinopinanediol (6), affords chiral secondary alcohols in useful chemical yields (70 ～ 93%) but in low optical purity (8 ～ 33% ee). Modifiers 5 and 6 are synthesized from (lR)-(-)-β-pinene in three steps.     

Y型分子筛固载(1S,2S)-DPEN-Ru(TPP)2催化苯乙酮不对称加氢

采用自由配体法将(1S,2S)-DPEN(1,2-diphenyl-1,2-ethylene-diamine)-Ru(TPP)2(TPP=三苯基膦,triphenylphosphine)配合物封装于NaY沸石分子筛超笼中,制备了(1S,2S)-DPEN-Ru(TPP)2/Y主客体材料(1S,2S)-DPEN=1,2-二苯基-1,2-乙二胺).采用等离子体发射光谱ICP、粉末X射线衍射(XRD)、紫外光谱(UV-Vis)、氮吸附等物理化学手段对所制备材料进行了表征.结果表明,(1S,2S)-DPEN-Ru(TPP)2配合物封装于Y型分子筛超笼中保持了原有的物理化学性能;作为苯乙酮不对称加氢催化剂,在优化条件下,苯乙酮的转化率可达100%,(R)-苯乙醇的对映体过量值(ee值)可达61.0%.该催化剂具有良好的稳定性和重复使用性.     

(Alk-1-ynyl)organylthiocarbenes: generation and reactions with olefins

1-Substituted 1-chloro-3-organylthiopropa-1,2-dienes 1a–f belonging to previously unknown type of allenic compounds were synthesized by chlorination of 1-organylthioalk-1-ynes 3a–f with N-chlorosuccinimide. The reactions of compounds 1a–f with Bu^tOK in hexane at –20 °C are accompanied by -elimination of HCl to give new alk-1-ynyl(organylthio)carbenes 2a–f, which add to olefins to form the corresponding 1-(alk-1-ynyl)-1-organylthiocyclopropanes 5 in yields of up to 60%. The electrophilic properties of carbenes 2 were confirmed experimentally.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2440–2447, November, 2004.     

Facile one pot multicomponent synthesis of novel 4-(benzofuran-2-yl)-2-(3-(aryl/heteryl)-5-(aryl/heteryl)-4,5-dihydro-1H-pyrazol-1yl)thiazole derivatives

An efficient base catalyzed one pot multicomponent reaction of aryl/hetryl chalcones, thiosemicarbazide and 1-(benzofuran-2-yl)-2-bromoethan-1-one was developed to synthesize the novel 4-(benzofuran-2-yl)-2-(3-(aryl/heteryl)-5-(aryl/heteryl)-4,5-dihydro-1H-pyrazol-1yl)thiazole derivatives.     

Spectral characterization and antimicrobial activity of Cu(II) and Fe(III) complexes of 2-(5-Cl/NO2-1H-benzimidazol-2-yl)-4-Br/NO2-phenols

The compounds of 2-(5-chloro/nitro-1H-benzimidazol-2-yl)-4-bromo/nitrophenols (HL_X : X = 1–4) and their copper(II) nitrate and iron(III) nitrate complexes have been synthesized and characterized. The structures of the complexes were confirmed on the basis of elemental analysis, thermal gravimetric analysis, molar conductivity and magnetic moment measurements, FT-IR, mass, and UV-Vis spectroscopy techniques. The complexes show high-thermal stability with >350°C m.p. In all complexes, the ligands are bidentate via one imine nitrogen and a phenolate oxygen. Cu(II) complexes having 1 : 2 M : L ratio are classified as non-electrolytes, whereas 1 : 1 M : L ratio is observed in Fe(III) complexes except [Fe(L₃)₂(H₂O)₂](NO₃) ? 3H₂O. The antimicrobial activities of the ligands and the complexes were evaluated using the disc diffusion method in DMSO as well as minimum inhibitory concentration dilution method against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus mirabilis. Antifungal activities were reported for Candida albicans. The complexes [Fe(L₃)₂(H₂O)₂](NO₃) ? 3H₂O and [Cu(L₃)₂] ? 2H₂O are more effective against S. epidermidis than ciprofloxacin.