Facile and Green Syntheses of 2-(N-Methylindole-3-carbonyl)-3-(N-methylpyrrol-2-yl)acrylonitriles and a Study of Their Antimicrobial Activities

Facile and green syntheses of substituted-2-(N-methylindole-3-carbonyl)-3-(N-methyl pyrrol-2-yl) acrylonitriles 6a–d are being reported. L-Proline has been utilized as an efficient and ecofriendly catalyst in aqueous medium for Knoevenagel condensation of pyrrole-2-carboxyaldehyde (1) and its N-methyl derivative (2) with the active methylene compounds 3-cyanoacetylindoles 3a–d at room temperature to afford substituted-2-(1H-indole-3-carbonyl)-3-(1H-pyrrol-2-yl)acrylonitriles 4a–d and substituted-2-(1H-indole-3-carbonyl)-3-(N-methylpyrrol-2-yl) acrylonitriles 5a–d respectively. Subsequently these products were treated with dimethyl sulfate (DMS) in polythylene glycol (PEG)–600 as an efficient and green solvent to afford the corresponding substituted-2-(N-methylindole-3-carbonyl)-3-(N-methylpyrrol-2-yl)acrylonitriles 6a–d. The antibacterial and antifungal activities of 4a–d, 5a–d, and 6a–d have been studied.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource: Full experimental and spectral details.]     

Interaction of 1-tert-perfluorobutyl-3,3-di(perfluoromethyl)-2-aziridinone with weak nucleophiles

The title perfluoro--lactam (1) was found to react with N,N-dimethylformamide to give initially a betaine (2) which undergoes ring enlargement to produce the isomeric 2-dimethylamino-3,4,4-tri(perfluoroalkyl)substituted 5-oxazolidone (3). Related betaines were also obtained on reaction of1 with pyridine, quinoline, benzalaniline, andp-dimethylaminobenzaldehyde.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 372–374, February, 1993.     

L-Proline-Catalyzed Knoevenagel Condensation: A Facile,Green Synthesis of (E)-Ethyl 2-Cyano-3-(1H-indol-3-yl)acrylates and (E)-3-(1H-Indol-3-yl)acrylonitriles

L-Proline has been utilized as a novel and ecofriendly catalyst in ethanol medium for the Knoevenagel condensation of indole-3-carboxyaldehydes and their N-methyl derivatives 1(a–e) and 4(a–e) with the active methylene compound, ethyl cyanoacetate (2) to afford substituted (E)-ethyl 2-cyano-3-(1H-indol-3-yl)acrylates 3(a–e) and 5(a–e) respectively. These products were reacted with dimethyl sulfate in the presence of PEG-600 as an efficient and green solvent to afford the corresponding N-mthylated derivatives 5(a–e). These Knoevenagel products react with 5% NaOH, yielding (E)-3-(1H-indol-3-yl)acrylonitriles 6(a–e) and 7(a–e).     

Synthesis of 2,3-bis(perfluoroalkyl)quinoxalines and 2,3-bis(perfluoroalkyl)-1,4-benzoxazines from oxides of internal perfluoroolefins

The reactions of oxides of internal trans-, cis-perfluoroolefins with o-phenylenediamine and 2-aminophenol in dioxane gave 2,3-bis(perfluoroalkyl)quinoxalines and 2,3-bis(perfluoroalkyl)-2H-1,4-benzoxazin-2-ols respectively in yields of 23-67%. When N,N-dimethylacetamide was used as a solvent an anionic isomerization of the oxides into ketones, which further yielded 2-(perfluoroalkyl)benzimidazoles in the case of o-phenylenediamine and 2-hydroxy-N-perfluoroalkanoylanilines in the case of 2-aminophenol, became the main path of these reactions. Unusual cyclization resulting in 2-pentafluoroethyl-2-pentafluoropropanoylbenzoxazolidine occurs on interaction between dodecafluoro-3,4-epoxyhexane and 2-aminophenol in N,N-dimethylacetamide.     

The first example of a preparative 1,4-perfluoroalkylation using (perfluoroalkyl)trimethylsilanes

Reactions of 2-perfluoroalkylchromones with (perfluoroalkyl)trimethylsilanes proceed as a 1,4-nucleophilic perfluoroalkylation to give 2,2-bis(perfluoroalkyl)chroman-4-ones in high yields after acid hydrolysis. Oxidation of 2,2-bis(trifluoromethyl)-6-methylchroman-4-one with K₂S₂O₈ leads to fluorinated analogs of natural lactarochromal and the corresponding acid.     

Fluoroalkylation of poly(cyclopentadienyl)siloxane and the surface properties of poly(fluorocyclopentenyl)siloxane films

In this work, poly(fluorocyclopentenyl)siloxane (FPCS) was obtained via a single electron transfer addition reaction of poly(cyclopentadienyl)siloxane (PCS) and perfluoroalkyl iodides, and reduction reaction of the intermediates. PCS was prepared by substitution and hydrolysis reactions using methyltrichlorosilane and sodium cyclopentadienide (NaCp) as raw materials. Fourier transform infrared (FTIR), ¹H NMR, and ¹⁹F NMR indicated the structures of the target polymers. The XPS results showed that the thin films prepared by dip-coating were fluorine enriched at the surface. Atomic force microscopy (AFM) image showed that on the rough surface of films, there were many pinnacles which were generated through the migration of side chain fluoroalkyl groups. The relative static contact angles of water and n-hexadecane on FPCS and PCS indicated that sodium dithionite initiated the reaction of perfluoroalkyl iodides and PCS so that FPCS was successfully synthesized. The measured surface energy of PCS was 2.57 × 10^?2 N/m; while FPCS was 2.14 × 10^?2 N/m, which represented better liquid repellent property compared to PCS.     

Reactions of Tris(Perfluoroalkyl)Difluorophosphoranes and Their Derivatives with Nucleophilic Reagents

Abstract

This paper is concerned with the reactions of (R_f)₃PF₂ and (R_f)₃PO with N-, 0-, C-nucleophiles and fluoride ion. Either the replacement of one or two perfluoroalkyl radicals by different functional groups or the addition of reagent to electrophilic phosphorus occurs. These phosphinic oxides and phosphoranes readily add fluoride-ion with the expansion of phosphorus coordination: the former produces phosphoranes OP a new type (R_f)₃P(F)O_?Cs₊, while the latter stable substituted fluorophosphates of general formula M ₊[(R_f)₃ PF₃]_?. Based on these salts it was possible to synthesize aryldiazonium tris(perfluoroalkyl)trifluorophosphates, whose thermal decomposition leads to the formation of substituted fluorobenzenes with high yields. The reaction is a convenient modification of the Shieman methd. The approaches of the synthesis of phosphoranes containing simultaneously both perfluoroalkyl groups and nonfluorin-ated radicals are developed due to the reactions of tris-(perf luoroalkyl)dif luorophosphoranes with the lithium-organic compounds. The replacement of either fluorine atom or perfluoroalkyl radical by the nonfluorinated group depends on the lithium reagent nature:     

HETEROCYCLES SYNTHESIS THROUGH REACTIONS OF NUCLEOPHILES WITH ACRYLONITRILES,PART 5, SYNTHESIS OF SEVERAL NEW THIAZOLE AND THIAZOLO[2,3-a]PYRIDINE DERIVATIVES

Abstract

Several new thiazole and thiazolo[2,3-a]pyridine derivatives were prepared by reaction of the thiazolin-4-one derivatives 2 (synthesised from α-cyano-2-ethylacetanilide and thioglycollic acid) with acrylonitriles 1a-h.     

Catalytic Hydrocyanation of Activated Terminal Alkynes

A universal, practical and scalable organocatalytic hydrocyanation manifold to provide β-substituted acrylonitriles bearing an electron-withdrawing functionality has been implemented. The catalytic manifold operates under the reactivity generation principle “a good nucleophile generates a strong base”, and it uses 1,4-diazabicyclo[2.2.2]octane (DABCO) as the catalyst, activated terminal alkynes as substrates and acetone cyanohydrin as the cyanide source. The acrylonitriles obtained as E,Z mixtures are straightforwardly resolved by simple flash chromatography delivering the pure isomers in preparative amounts.     

A One‐Pot Synthesis of 1,3‐Dihydro‐1,3,3‐tris(perfluoroalkyl)isobenzofuran‐1‐olates and Their Complete NMR Spectroscopic Analysis on the Basis of 1D and 2D Experiments

A convenient synthesis of the 1,3‐dihydro‐1,3,3‐tris(perfluoroalkyl)isobenzofuran‐1‐ols 3a , b was elaborated starting from commercially available phthaloyl dichloride and trimethyl(perfluoroalkyl)silanes (Me₃SiR_f) 1a , b (R_f=CF₃, C₂F₅) in the presence of a fluoride source (Schemes 1 and 3). In a reaction analogous to alkyl Grignard reagents, double chloride substitution by two perfluoroalkyl groups and subsequent addition of one perfluoroalkyl group with concomitant ring closure led to this new class of compounds (Scheme 2). The syntheses of the alcohols and some alcoholates, as well as of the corresponding trimethylsilyl ethers are described. A combination of special 1D and 2D NMR experiments allowed the assignment of all atoms of the new compounds. The solid‐state structure of 1,3‐dihydro‐1,3,3‐tris(trifluoromethyl)isobenzofuran‐1‐ol ( 3a ) was elucidated by X‐ray diffraction methods.     

4-Oxo-3,4-dihydroquinazolinyl- and Benzimidazolylacetonitriles in Annelation Reactions of a Haloquinoline Ring

The interaction of 4-oxo-3,4-dihydroquinazolinyl- and benzimidazolylacetonitriles with 2,6-dihalobenzaldehydes leads to 3-(2,6-dihalophenyl)-2-(4-oxo-3,4-dihydro-2-quinazolinyl)acrylonitriles and 2-(1H-benzo[d]imidazol-2-yl)-3-(2,6-dihalophenyl)acrylonitriles respectively. As a result of intramolecular cyclization of these nitriles 4-halo-12-oxo-12H-quino[2,1-b]quinazoline-6-carbonitriles and 4-halobenzo[4,5]imidazo[1,2-a]quinoline-6-carbonitriles respectively are formed.     

Visible-light-promoted alkylation of unsaturated MIDA boronates using Ru(bpy)3Cl2 as the photoredox catalyst

The development of a visible light-mediated atom transfer radical addition (ATRA) of perfluoroalkyl iodides to ethynyl-, vinyl- and allyl-MIDA boronates using the reductive and oxidative quenching of [Ru(bpy)₃]Cl₂ is described. Using an operationally simple and mild protocol, the corresponding MIDA boronates containing perfluoroalkyl groups were obtained in moderate to high yields. The structures of three products were confirmed by single crystal X-ray diffraction studies.     

Reactions of 3-alkylsulfanyl-2-arylazo-3-(1-azacycloalk-1-yl)acrylonitriles with maleimide

Reactions of 2-arylazo-3-(1-azacycloalk-1-yl)-3-methylsulfanylacrylonitriles with male-imide in benzene gave octahydropyrrolo[3,4-a]pyrrolizines 2a–c, decahydro-2,7a-diaza-cyclopenta[a]indene 2e, and decahydro-5-oxa-2,7a-diazacyclopenta[a]indene 2f as a result of 1,3-dipolar cycloaddition. In a similar reaction with 3-allylsulfanyl-2-arylazo-3-(1-azacycloalk-1-yl)acrylonitriles 3, dipolar cycloaddition and intramolecular cyclization competed to give a mixture of compounds 2 (major products) and 1,4,6,7,8,8a-hexahydropyrrolo[2,1-c]-1,2,4-triazines 4b–d, 1,6,7,8,9,9a-hexahydro-4H-pyrido[2,1-c]-1,2,4-triazine 4e, and 1,4,6,7,9,9a-hexahydro-1,4-oxazino[3,4-c]-1,2,4-triazine 4f (minor products).     

ABC mesogens: a novel ‘hexagonal columns‐in‐lamellae’ morphology of low molar mass partially fluorinated ‘three‐chain’ benzoic acids

Two homologous series of 3,4,5‐tris(perfluoroalkylalkyloxy)benzoic acids (K3S[n,m]), with alkyl chain lengths m ?=?8 and 11 and perfluoroalkyl chain length n ?=?6,8 and 10, have been investigated with respect to their liquid crystalline behaviour and, in particular, the structure of the mesophases exhibited. The mesophase characterization was performed by means of polarising optical microscopy, differential scanning calorimetry and X‐ray diffraction of powder‐like samples. At a first glance, the results for each compound indicate the presence of a classical hexagonal columnar mesophase. However, a comparative study of the small angle diffractograms of the two series with alkyl chain lengths m ?=?8 and 11 reveal an increasing lamellar arrangement within the hexagonal columnar lattice on increasing the perfluoroalkyl chain length n . A conclusive explanation leads to a mesophase structure combining both a hexagonal arrangement of the carboxylic groups and a layer arrangement of the perfluoroalkyl chains. The model has been proved by simulation of the X‐ray diffractograms using corresponding molecular models. This is the first evidence for the existence of a ‘hexagonal columns‐in‐lamellae’ morphology, realized by low molar mass compounds, and is analogous to a similar phase structure of linear ABC triblock copolymers.     

Synthesen und Eigenschaften von Bis(perfluoralkyl)zink‐Verbindungen

Syntheses and Properties of Bis(perfluoroalkyl)zinc Compounds The conditions for the syntheses of bis(perfluoroalkyl)zinc compounds Zn(R_f)₂ · 2 D (R_f = C₂F₅, n‐C₃F₇, i‐C₃F₇, n‐C₄F₉, n‐C₆F₁₃, n‐C₇F₁₅, and n‐C₈F₁₇; D = CH₃CN, tetrahydrofurane, dimethylsulfoxide) are described. Mass spectra, thermal decompositions, ¹⁹F‐ and ¹³C‐NMR spectra are discussed.     

全氟烷基磺酰亚胺盐催化芳香化合物硝化反应的研究

利用系列全氟烷基磺酰亚胺盐[M(NPf₂)_n]作为一种新型的Lewis酸催化剂，用于催化芳香化合物与等摩尔65% (m∶m)硝酸的硝化反应. 通过考察不同的催化剂、反应时间、反应温度和反应介质效应等因素对甲苯硝化的影响，以及比较1 mol% Yb[N(C₄F₉SO₂)₂]₃催化不同结构的取代芳烃硝化反应的效果，表明全氟烷基磺酰亚胺盐不仅具有环境友好和原子经济的特点，而且是一类比常规Lewis酸更有效的、芳香化合物硝化反应的催化剂.     

Synthesis and Alkylation of Piperidinium 4,5-trans-3-Cyano-6-hydroxy-4-(2-iodophenyl)-6-methyl-5-(2-methylphenyl)carbamoyl-1,4,5,6-tetrahydropyridine-2-thiolate. Molecular and Crystal Structure of 3-(2-Iodophenyl)-2-(4-phenyl-2-thiazolyl)acrylonitrile

The reaction of o-iodobenzaldehyde, cyanothioacetamide, and N-acetoacetyl-o-toluidine in the presence of piperidine gave piperidinium 4,5-trans-3-cyano-6-hydroxy-4-(2-iodophenyl)-6-methyl-5-(2-methylphenyl)carbamoyl-1,4,5,6-tetrahydropyridine-2-thiolate used in the synthesis of substituted 4,5-trans-2-alkylthiotetrahydropyridines and 2-(2-thiazolyl)acrylonitriles. The structure of 3-(2-iodophenyl)-2-(4-phenyl-2-thiazolyl)acrylonitrile was studied using X-ray diffraction structural analysis.     

The homologous tert-amino effect: a route to fused 2-benzazepine derivatives

2-Cyano- and 2-carbethoxy-3-[2-(pyrrolidin-1-ylmethyl)phenyl]acrylonitriles were prepared through either amination of appropriate 3-[2-(bromomethyl)phenyl]acrylonitriles with pyrrolidine or condensation of 2-(pyrrolidin-1-ylmethyl)benzaldehyde with malononitrile and ethyl cyanoacetate. These acrylonitrile derivatives were shown to undergo easy mutual interconversion with 1-(pyrrolidin-1-yl)indane-2-carbonitriles driven by solvent polarity. Upon heating at 140-150 °C both acrylonitrile and indane derivatives were found to give 2,3,5,10,11,11a-hexahydro-1H-pyrrolo[1,2-b][2]benzazepine-11-carbonitriles. All transformations observed were rationalized in the terms of reactions related to the tert-amino effect. Furthermore, the corresponding piperidin-1-yl and azepan-1-yl analogs of the above acrylonitriles and indanes were obtained similarly. By analogy their heating afforded 1,2,3,4,6,11,12,12a-octahydropyrido[1,2-b][2]benzazepine-12-carbonitriles and 7,8,9,10,11,11a, 12,13-octahydro-5H-azepino[1,2-b][2]benzazepine-12-carbonitriles.     

Rhodium-catalyzed asymmetric hydrogenation of β-acetylamino acrylonitriles

The rhodium-catalyzed asymmetric hydrogenation of β-acetylamino acrylonitriles was investigated by using monophosphine and bisphosphine ligands. It was found that an Rh-QuinoxP^∗ complex exhibited high enantioselectivities for β-aryl substituted β-acetylamino acrylonitriles and the Rh-JosiPhos CyPF-t-Bu complex was proven to be effective for the hydrogenation of tetrasubstituted olefins from cyclic β-acetylamino acrylonitriles.