Simple route to 3-(2-indolyl)-1-propanones via a furan recyclization reaction

A simple route to 1-R-3-(2-indolyl)-1-propanones has been elaborated based on recyclization of 2-(2-aminobenzyl)furan derivatives. Being a modification of the Reissert indole synthesis, our approach employs the furan ring as a source of carbonyl function. This approach is general and allows varying of substituents in aromatic ring as well as in 3-position of indole nucleus.     

The chemiluminescence mechanism of 3,4-bis(3-indolyl)-1H-pyrrole-2,5-dione, and the characteristics of chemiluminescence developed in the reaction with CH(3)CNH(2)O(2)NaOH

The chemiluminescence (CL) mechanism of 3,4-bis(3-indolyl)-1H-pyrrole-2,5-dione (IPD) was investigated using liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS) of the products formed after the IPD CL reaction. We found that IPD produced strong CL via the decomposition of dioxetane formed after oxidation of the maleimide and indole moieties in the presence of CH₃CN, H₂O₂ and NaOH. The IPD CL was used for evaluating the antioxidant effect on curcumin and epigallocatechin gallate.     

Michael reaction of indoles with 3-(2′-nitrovinyl)indole under solvent-free conditions and in solution. An efficient synthesis of 2,2-bis(indolyl)nitroethanes and studies on their reduction

Michael reaction of 3-(2′-nitrovinyl)indole with eight 3-unsubstituted indoles on TLC-grade silica gel furnished unsymmetrical bis(indolyl)nitroethanes in 7-12 min under microwave irradiation and in 8-14 h at rt. In contrast, the p-TsOH-catalysed reaction of the nitrovinylindole with the 3-unsubstituted and two 3-substituted indoles in solution under reflux furnished both unsymmetrical and symmetrical bis(indolyl)nitroethanes, the latter resulting from novel tandem Michael addition-elimination-Michael addition reactions. The synthesis of a 2′,3″-bis(indolyl)nitroethane, the precursor core structure of two bioactive marine metabolites, and the reduction of 2,2-bis(3′-indolyl)nitroethane to the corresponding ethylamine, isolated as its N-acetyl derivative, have been achieved. Significantly, attempted hydrolysis of three nitronates, derived from the corresponding bis(indolyl)nitroethanes, with buffered aqueous TiCl₃ has led to the first isolation of oximes (syn/anti-mixture) as the only products.     

Multicomponent reactions for the synthesis of new 3′-indolyl substituted heterocycles under microwave irradiation

A series of polysubstituted (3′-indolyl)pyrazolo[3,4-b]pyridine and (3′-indolyl)benzo[h]quinoline derivatives were synthesized via one-pot multicomponent reactions of aldehydes, 3-cyanoacetyl indoles with 5-aminopyrazol or naphthylamine under microwave irradiation. Particularly valuable features of this method include high yields of products, broad substrate scope, short reaction time and straightforward procedure.     

Synthesis of 2,5-diethyl-3,4-bis(trifluoromethyl)furan and its derivatives

The addition reaction of propionaldehyde to hexafluoro-2-butyne ( 1 ) under γ-ray irradiation gave trans-6,6,6-trifluoro-4-trifluoromethyl-4-hexen-3-one ( 2 ) and 4,5-bis(trifluoromethyl)octa-3,6-dione ( 3 ). The latter compound was treated with sulfuric acid to give 2,5-diethyl-3,4-bis(trifluoromethyl)furan ( 4a ). Several reactions, such as bromination, dehydrobromination and oxidation, were carried out to prepare derivatives of 4a .     

An effective method for the preparation of mono N-alkyl derivatives of 1,1′-bis(6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline)

The condensation of 1,1′-bis(6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline) with alkyl, aralkyl and aryl aldehydes, but not ketones, in ethanol or chloroform provides useful cyclic aminal [8-substituted 5,6,10,11,15b,15c-hexahydro-2,3,13,14-tetramethoxy-8H-imidazo[5,1-a:4,3-a′]diisoquinoline] intermediates that when subsequently treated with sodium cyanoborohydride in ethanol, followed by the addition of 2 M hydrochloric acid, gave monosubstituted N-alkyl 1,1′-bis(6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline) derivatives in very high yields. The rates of the initial condensation with four different aldehydes were measured, and the entire sequence was successfully applied in one example to a ‘one-pot’ process; this signals a versatile route to differentially N-substituted 1,1′-bis(1,2,3,4-tetrahydroisoquinoline) derivatives.     

Synthesis and properties of N,N,N′,N′-tetrasubstituted 1,3-bis(5-aminothien-2-yl)azulenes and their application as a hole-injecting material in organic light-emitting devices

Two title compounds, N,N,N′,N′-tetraphenyl-1,3-bis(5-aminothien-2-yl)azulene (3a) and 1,3-bis{5-(9-carbazolyl)thien-2-yl}azulene (3b), were synthesized from 1,3-di(2-thienyl)azulene (4) by a two-step sequence involving bromination and subsequent Pd-catalyzed amination. These compounds were characterized by spectroscopic analyses and the structure of 3a was determined by X-ray crystallographic analysis. Their HOMO energy levels were estimated using their electrochemical oxidation potentials, and these compounds were used as a hole-injecting material in organic light-emitting devices. The device with 3a showed greater durability than that with copper phthalocyanine.     

Anhydro base of 4-(3-indolyl)pyrimidine

The reaction of 4-(3-indolyl)pyrimidine methiodide with alkali gives a stable anhydro base, which reacts under mild conditions with methyl iodide to give 1-methyl-4-(1-methyl-3-indolyl)pyrimidinium iodide. On the basis of the calculated molecular diagrams of both compounds it was concluded that they have high reactivities. The reaction of the anhydro base with an aqueous methanol solution of KOH, concentrated NH₄OH, hydrazine hydrate, and a mixture of malonic acid dinitrile with triethylamine leads to 3-acetylindole, 4-(3-indolyl)pyrimidine, 3(5)-(3-indolyl)pyrazole, and 2-amino-3-cyano-6-(3-indolyl)pyridine, respectively. 1-Methyl-4-(1-methyl-3-indolyl)pyrimidinium iodide under the same conditions gives similar compounds that contain a methyl group attached to the indole nitrogen atom. The structures of the synthesized compounds were confirmed by their IR, UV, PMR, and mass spectra.See [1] for our preliminary communication.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 212–218, February, 1982.     

Synthesis and anti-HIV activities of bis-(cycloSaligenyl) pronucleotides derivatives of 3′-fluoro-3′-deoxythymidine and 3′-azido-3′-deoxythymidine

Anti-HIV nucleoside monophosphates have limited cellular uptake due to the presence of negatively-charged phosphate group. Bis-(cycloSaligenyl) derivatives containing two anti-HIV nucleosides, 3′-fluoro-3′-deoxythymidine (FLT) and 3′-azido-3′-deoxythymidine (AZT) were synthesized to increase intracellular delivery of nucleoside monophosphates. 2,5-Bis(hydroxymethylene)benzene-1,4-diol was selected as a monocyclic bidentate scaffold and synthesized by three different methods from bis(hydroxymethylene)cyclohexan-1,4-diene-1,4-diol, or diethyl 2,5-dihydroxyterephthalate. The reaction of the tetraol with diisopropylphosphoramidous dichloride in the presence of 2,6-lutidine, followed by conjugation reactions with nucleosides (i.e., FLT and AZT) and oxidation afforded symmetrical and unsymmetrical bis-(cycloSaligenyl) diphosphate triester products, AZT-AZT, FLT-FLT, and FLT-AZT conjugates, in 63-74% overall yields and modest anti-HIV activities (IC₅₀ = 2.8-69.6 μM).     

Synthesis of platinum-iodo-alkyl/aryl complexes in ligand-exchange reactions: Determination of the structure of Pt{(S,S)-bdpp}(X)I complexes (X = Me, I) by X-ray crystallography

Pt{(S,S)-bdpp}(R)I (bdpp = 2,4-bis(diphenylphosphino)pentane; R = Me, Ph, Bz, 2-Tioph) complexes were formed in alkyl/aryl ligand - iodide ligand-exchange reactions by reacting the corresponding Pt{(S,S)-bdpp}R₂ complexes with methyl iodide. The Pt{(S,S)-bdpp}(Me)I complex was isolated and fully characterised. The influence of the X ligand on the platinum-bdpp chelate conformation was investigated in Pt{(S,S)-bdpp}(X)I (X = I, SnCl₃, Me) complex series by means of X-ray crystallography.     

Synthesis, crystal and molecular structure of gold(I) thiophenolate with 4′-ferrocenyl[1,1′]biphenylisocyanides

The syntheses of ferrocenylbiphenylisocyanide gold(I) thiophenolato complexes are described. The preparative route starts from ferrocenylphenylbromide and proceeds in six steps to yield the desired gold(I) complexes, (thiophenolato)gold{(4′-ferrocenyl[1,1′]biphenyl-4-yl)isocyanide} (11) and (thiophenolato)gold{(4′-ferrocenyl-3,5-dimethyl[1,1′]biphenyl-4-yl)isocyanide} (12) in good yields. The synthetic pathways were developed as a first step toward realizing the goal of preparing metallomesogens based on ferrocenyl-polyphenylenes coordinated to gold(I) thiophenolates, in which long chain alkoxy groups are substituted para to sulfur on the phenyl ring. The crystal structures of (chloro)gold{(4^′-ferrocenyl[1,1′]biphenyl-4-yl)isocyanide} (9) and 12 are reported. Complex 9 crystallizes in the space group P2₁/c and 12 crystallizes in P2₁/n. Complexes 9 and 12 show short intermolecular Au-Au contacts of 3.3765(7) Å and 3.3334(3) Å, respectively.     

Synthesis of 1,3-bis[(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)(dimethoxyphosphoryl)methyl]-4,6-dimethoxybenzene

A reaction of 1,3-dimethoxybenzene with dimethyl (3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidenemethyl)phosphonate gave rise to 1,3-bis[(3,5-di-tert-butyl-4-hydroxyphenyl)-(dimethoxyphosphoryl)methyl]-4,6-dimethoxybenzene, which was oxidized to 1,3-bis[(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)(dimethoxyphosphoryl)methyl]-4,6-dimethoxy-benzene.     

Synthesis and optical properties of conjugated N,N-dimethyl and thienyl end-capped 2,5-(arylethynyl)thiophene oligomer structures

End-capped (N,N-dimethylaminophenyl) and 2′-thienylethynyl 2,5-thiophene oligomer structures were synthesized by heterocoupling between the terminal acetylenes such as: p-(N,N-dimethylaminophenyl)ethyne (3) [or 1-(p-(N,N-dimethylaminophenyl)-2-p-(ethynylphenyl)ethyne, 4]; p-(β-ethenyl-2′-thienyl)phenylethyne (E-9) [or p-(β-ethynyl-2′-thienyl)phenylethyne, 11], and 2,5-diiodothiophene, catalyzed by the Cl₂Pd(PPh₃)₂/CuI system, in good to excellent yields. The 2,5-di[(3′,5′-di(trimethylsilylethynyl)phenyl]_x-1-ethynyl]thiophene oligomers were prepared by heterocoupling between 3′,5′-di[(trimethylsilylethynyl)phenyl]_x-1-ethyne (n = 0-2) terminal acetylenes and 2,5-diiodothiophene, in excellent yields. The terminal acetylenes were efficiently prepared by a specific protection-deprotection methodology. All the ethynylphenyl compounds obtained show fluorescence radiation emission, with a bathochromic shift of the wavelength that increases with the chain conjugation.     

Synthesis of aryl/alkyl(2,2′-bis-3-methylindolyl)methanes and aryl(3,3′-bis indolyl)methanes promoted by secondary amine based ionic liquids and microwave irradiation

Aryl/alkyl(2,2′-bis-3-methylindolyl)methanes and aryl(bis-3,3′-indolyl)methanes are synthesized in high yield using ionic liquids mediated by microwave. Reaction conditions and product recovery are simple and ionic liquids could be recycled.     

Synthesis of furan 4′-thio-C-nucleosides, their methylsulfonium and sulfoxide derivatives. Evaluation as glycosidase inhibitors

A series of furan C-nucleosides having a sulfur atom in the sugar ring were synthesised. The α and β anomers of 3-ethoxycarbonyl-2-methyl-5-(4′-thio-d-erythrofuranosyl)furans 10 and 11 were obtained by acid treatment of (4′-S-acetyl-4′-thio-d-arabino-tetritol-1-yl)furan 9. Oxidation of 10 with m-chloroperbenzoic acid gave sulfoxide 12 as one epimer at the sulfur atom whereas 11 was transformed into sulfoxide 13 as an epimeric mixture. S-Methylation of 10 and 11 with methyl triflate led to sulfonium salts 14 and 15. The prepared compounds were found to be moderate inhibitors of α-l-fucosidase.     

Electrolytic methoxylation of 3,4-bis(hydroxymethyl) furan and synthesis of 4,5-bis-(hydroxymethyl) pyridazine

3,4-Bis(hydroxymethyl)furan was electrolytically methoxylated during intense cooling. 4,5-Bis(hydroxymethyl)pyridazine was obtained by reaction of the methoxylation product — 2,5-dimethoxy-3,4-bis (hydroxymethyl)-2,5-dihydrofuran — with hydrazine hydrate.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1306–1307, October, 1970.     

Synthesis of N,N′-bis and N,N,N′,N′-tetra-[(3,5-di-substituted-1-pyrazolyl)methyl]para-phenylenediamines: new candidate ligands for metal complex wires

A series of tridentate ligands N,N-bis-[(di-substituted-1-pyrazolyl)methyl]arylamines 2-3a,b and benzylamine 4a,b, tetradentate N,N′-bis-[(di-substituted-1-pyrazolyl)methyl]para-phenylenediamines 7a,b and hexadentate N,N,N′,N′-tetra-[(di-substituted-1-pyrazolyl)methyl]para-phenylenediamines 8a,b has been prepared in good yield by condensation of arylamines, benzylamine or para-phenylenediamine with N-hydroxymethyl disubstituted pyrazoles 1a,b. The synthesis and characterisation of these various polydentate ligands are described.     

Polyamides of 2,5-bis(amino methyl) 1,4-dioxane and dicarboxylic acids

Novel polyamides of 2,5-bis(amino methyl) 1,4-dioxane (cis/trans-BAMD) with adipic/sebacic acids and of 2,5-bis(carboxy methyl)/2,5-bis(carboxy) 1,4-dioxane with 1,6-hexane diamine have been prepared. Because of the slightly higher conformational flexibility of the 1,4-dioxane ring in comparison with that of the cyclohexane ring, the BAMD polyamides have lower T_g and T_m than the corresponding 1,4-bis(amino methyl) cyclohexane (BAMC) polyamides. The symmetry of the trans-dioxane moiety permits high crystallinity in the trans-BAMD polymers. The crystallinity T_g and T_m of the trans polymers are decreased with the incorporation of the cis-dioxane moiety which lacks a plane of symmetry. Because of the hydrophilic nature of the dioxane ring, t-BAMD-6 has good moisture-regain properties, yet is melt processable (T_m = 292°C).     

New N-acyl, N-alkyl, and N-bridged derivatives of rac-6,6′,7,7′-tetramethoxy-1,1′,2,2′,3,3′,4,4′-octahydro-1,1′-bisisoquinoline

The preparation of potential new ligand systems based on the rac-1,1′,2,2′,3,3′,4,4′-octahydro-6,6′,7,7′-tetramethoxy-1,1′-bisisoquinoline skeleton has been investigated. Syntheses of N-(2-bromobenzyl), N-(3-acetoxybenzyl), N-acetyl, N-chloroacetyl, N-chlorocarbonyl, N-ethoxycarbonyl and N-tert-butyloxycarbonyl derivatives and five macrocyclic, polyether containing derivatives are described.     

Metalloporphyrins as chemical shift reagents: the unambiguous NMR characterization of the cis- and trans-isomers of meso-(bis)-4′-pyridyl-(bis)-4′-carboxymethylphenylporphyrins

The condensation of pyrrole with 4-pyridylcarboxyaldehyde and methyl 4-formyl benzoate under Adler-Longo conditions yielded the series of meso-(4′-pyridyl)/(4′-carboxymethylphenyl)porphyrins as a mixture. Careful column chromatography afforded each isomer in pure form. In this paper we focus on the two bis-substituted isomeric meso-porphyrins, 5,10-bis(4′-pyridyl)-15,20-bis(4′-carboxymethylphenyl)porphyrin and 5,15-bis(4′-pyridyl)-10,20-bis(4′-carboxymethylphenyl)porphyrin, respectively, 4′-cis and 4′-transDPyDMeP. The assignment of the geometry of the two isomers was performed by ¹H NMR spectroscopy on the trinuclear adducts [(4′-cisDPyDMeP){Ru(TPP)(CO)}₂] and [(4′-transDPyDMeP){Ru(TPP)(CO)}₂], obtained by selective coordination of [Ru(TPP)(CO)(EtOH)] (TPP=tetraphenylporphyrin) to the peripheral nitrogen atoms. The axially bound ruthenium porphyrins act as chemical shift reagents on the central porphyrin, allowing a clear distinction of the pyrrole proton resonances and consequent unambiguous assignment of the geometry of each isomer based upon symmetry considerations.