Design,Synthesis, Characterization,and Antimicrobial Evaluation of Novel 2‐(3, 5‐di methoxy‐4‐((1‐aryl‐1H‐1, 2, 3‐triazole‐4‐yl) methoxy) phenyl) benzo[d]thiazoles

A series of 12 new 2‐(3, 5‐dimethoxy‐4‐((1‐Aryl‐4H‐1, 2, 3‐triazol‐4‐yl) methoxy) phenyl) benzo[d]thiazoles have been synthesized from the reaction of 4‐hydroxy‐3, 5‐dimethoxybenzaldehyde, o‐amino thiophenol, propargyl bromide, and different substituted aromatic azides using “click chemistry”. The structures of these compounds were established on the basis of Fourier Transform infrared, ¹H NMR, ¹³C–NMR, and mass spectral analysis. Compounds ( 6a–l ) were screened for in vitro antimicrobial activity.     

Microwave‐assisted Synthesis,Characterization, and Density Functional Theory Study of Biologically Active Ferrocenyl Bis‐pyrazoline and Bis‐pyrimidine as Organometallic Macromolecules

Organometallic macromolecules such as ferrocenyl bis‐pyrazoline ( 2 , 3 ) and bis‐pyrimidine ( 4 , 5 ) derivatives were synthesized by reacting ferrocenyl bis‐chalcone 1 with thiosemicarbazide/phenylhydrazine/guanidine hydrochloride/thiourea, respectively, under microwave irradiation. Ferrocenyl bis‐chalcone 1 was synthesized by reacting acetyl ferrocene with terephthalaldehyde. Synthesized compounds were characterized by using IR, ¹H NMR, ¹³C NMR, EI‐MS, and elemental analysis. In vitro antibacterial activity against two Gram‐negative and two Gram‐positive bacteria was determined by the disc diffusion assay. Moreover, minimum inhibition concentrations were also measured with reference to chloramphenicol. Thioamide functionally containing ferrocenyl bis‐pyrazoline derivative 2 shows the best antibacterial activity on Escherichia coli and Salmonella typhimurium, among all tested compounds including the reference drug chloramphenicol. The structure–activity relationship is also developed by using computational calculations with density functional theory (DFT)/B3LYP method.     

Preparation,characterization and biological studies of some novel ferrocenyl compounds

Reaction of ferrocene with trichloroacetimidates in the presence of TMSOTf as a catalyst gave a series of novel ferrocenyl compounds, 1–7, in good yield and by a simple method using the Friedel–Crafts reaction. Only monosubstituted ferrocenyl compounds were obtained by flash chromatography at room temperature. Attempts to separate the disubstituted ferrocenyl compounds were unsuccessful, even in the presence of excess (2:1, 3:1 or 4:1) of trichloroacetimidates. The prepared compounds have been characterized by ¹H NMR, ¹³C NMR, IR, UV–vis and mass spectra as well as elemental analysis. The prepared compounds showed medium to good antimicrobial activity against Bacillus subtilis (+ve), Staphylococcus aureus (+ve), Candida albicans (yeast), Escherichia coli (?ve), Salmonella typhi (?ve), Aspergillus niger (fungi) and Fusarium solani (fungi). Copyright © 2005 John Wiley & Sons, Ltd.     

Synthesis,characterization, and antimicrobial activity of cobalt(II), nickel(II), copper(II) and zinc(II) complexes with ferrocenyl Schiff bases containing a phenol moiety

Three ferrocenyl Schiff bases containing a phenol moiety have been formed by 1:1 molar condensation of acetylferrocene with 2‐aminophenol, 2‐amino‐5‐picoline or 2‐amino‐5‐chlorophenol. These ligands form 2:1 complexs with cobalt(II), copper(II), nickel(II), and zinc(II) ions. From the different spectral data, it was found that coordination of the ligands with the metal ions takes place via the azomethine nitrogen atoms and the deprotonated oxygen of the phenol groups. These ligands and their complexes have been characterized by IR, ¹H NMR, ¹³C NMR, UV–Vis spectra, and elemental analysis. The spectral data of the ligands and their complexes are discussed in connection with the structural changes due to complexation. The complexes prepared showed good antimicrobial activity against Escherichia coli, Bacillus subtilus, and Candida albicans. Copyright © 2004 John Wiley & Sons, Ltd.     

A series of novel ferrocene‐based dipeptide receptors for electrochemistry and biological activity

Synthesis of ferrocene‐based dipeptide receptors FcL1 , FcL2 , FcL3 , FcL4 , FcL5 was carried out by the acylation reaction of ferrocenecarboxylic acid with dipeptide esters. Compounds were characterized by IR, ¹H NMR, ¹³C NMR and elemental analysis. Single‐crystal X‐ray analysis of FcL3 showed it has two independent chiral molecules and the two chiral atoms (C12 and C35) are in R configuration. Their cyclic voltammetric behaviors showed a pair of well‐defined and stable redox waves in the potential range 0.00–1.00 V. The configuration of the metals influenced the receptor's characteristics greatly, and at the same time the FcL compounds could selectively sense group IIB metal ions Zn²⁺, Cd²⁺ and Hg²⁺. The biological activities of FcL1 , FcL2 , FcL3 , FcL4 , FcL5 were studied against the tested bacteria; among them, FcL4 showed significant activity against all five bacterial strains tested. Copyright © 2013 John Wiley & Sons, Ltd.     

Heterobimetallic Nickel(II) Complexes of Ferrocenyldithiophosphonates. Molecular Structures of [{FcP(OR)S2}2Ni] [Fc = Fe(η5‐C5H4)(η5‐C5H5), R = Et,Pri, Bus,Bui]

The reaction of 2,4‐diferrocenyl‐1,3‐dithiadiphosphetane 2,4‐disulfide [FcPS(μ‐S)]₂ [Fc = Fe(η⁵‐C₅H₄)(η⁵‐C₅H₅)] with alcohols ROH gave the corresponding ferrocenyldithiophosphonic acids [FcPS(OR)(SH)], which were treated in situ with Ni(CH₃COO)₂·4H₂O in acetic acid to yield the square‐planar heterobimetallic trinuclear complexes [{FcP(OR)S₂}₂Ni] (R = Me ( 1 ), Et ( 2 ), Prⁱ ( 3 ), Bu^s ( 4 ) and Buⁱ ( 5 )). Compounds 1‐5 were characterized by elemental analysis, MS, NMR (¹H, ¹³C and ³¹P), IR spectroscopy, and 2‐5 also by X‐ray crystallography. Cyclovoltammetric studies on the heterobimetallic nickel(II) complexes 1‐5 showed irreversible reduction to unstable nickel(I) complexes and an irreversible two‐electron oxidation of the sulfur‐containing nickel fragments, followed by a reversible one‐electron oxidation of the two ferrocenyl groups.     

Structural determination of aspericins A?C,new furan and pyran derivates from the marine‐derived fungus Rhizopus sp. 2‐PDA‐61, by 1D and 2D NMR spectroscopy

Three new furan and pyran derivatives named aspericins A? C (1–3), as well as a known asperic acid (4), have been isolated from the marine‐derived fungus Rhizopus sp. 2‐PDA‐61. The complete ¹H and ¹³C NMR assignments for the new compounds were carried out using ¹H, ¹³C, DEPT, COSY, HMQC, HMBC, and NOESY NMR experiments. Compounds 1–3 were evaluated for their cytotoxic activities on P388, A549, HL‐60, and BEL‐7420 cell lines by the MTT and SRB methods. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis and physico-analytical studies of some novel ferrocenyl Schiff base derivatives

A series of ferrocenyl Schiff base derivatives was synthesized by condensation reactions of 1,1′-ferrocenedicarboxaldehyde and aromatic amines containing long chain alkyl groups as free ends which were characterized by their physical properties, elemental, FTIR, ¹H NMR, ¹³C NMR spectral and thermal analysis. The thermal behaviour of the synthesized compounds was studied by differential scanning calorimetry (DSC) which revealed that these compounds may exhibit mesomorphic properties. The DSC results of aromatic amines and ferrocenyl Schiff bases were compared to study the effects of structure, i.e. rigid core and terminal chain length, on the phase transition behaviour.     

Synthesis,Photophysical Properties,and Antimicrobial Activity of Novel Styryl Colorants Derived from 7‐Methoxy‐1,4‐diphenethyl‐1,2,3,4‐tetrahydroquinoxaline‐6‐carbaldehyde

The novel 1,4‐diphenethyl‐1,2,3,4‐tetrahydro‐7‐methoxyquinoxalin‐6‐carbaldehyde was synthesized by reductive alkylation of 6‐methoxy quinoxaline with phenyl acetic acid and was further subjected to Knoevenagel condensation with various active methylene compounds to synthesize novel styryl colorants. Photophysical properties of styryl colorants were studied using UV–visible and fluorescence spectroscopy. These colorants displayed orange to violet hue and showed fluorescence emission maxima in the region of 560–640 nm, and displayed a large Stokes shift (85–104 nm). Compounds were subjected to thermogravimetric analysis which showed excellent stability up to 310°C. These styryl compounds were evaluated for their antimicrobial study as antifungal against Candida albicans C. albicans and Aspergillus niger and antibacterial against Escherichia coli and Staphylococcus aureus. The results revealed good antimicrobial activity against tested organisms. The synthesized chromophores were characterized using elemental analysis, FTIR, ¹³C‐NMR and ¹H‐NMR spectroscopy and mass spectrometry.     

Synthesis,structural characterization and cytotoxic activity of organotin derivatives of indomethacin

The synthesis, characterization and cytotoxic properties in vitro of tri‐n‐butyltin 1‐(4‐chlorobenzoyl)‐5‐methoxy‐2‐methyl‐1H‐indole‐3‐acetate ( 1 ), tri‐phenyltin 1‐(4‐chlorobenzoyl)‐5‐methoxy‐2‐methyl‐1H‐indole‐3‐acetate ( 2 ), tetra‐n‐butyltin[bis‐1‐(4‐chlorobenzoyl)‐5‐methoxy‐2‐methyl‐1H‐indole‐3‐acetato]distannoxane ( 3 ) and di‐n‐butyltin bis‐1‐(4‐chlorobenzoyl)‐5‐methoxy‐2‐methyl‐1H‐indole‐3‐acetate ( 4 ) are described. These compounds have been characterized by ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopy in solution and ¹¹⁹Sn NMR in the solid state, infrared spectroscopy, elemental analysis and X‐ray diffraction for compound 1 . The growth inhibition effects of compounds 1–4 against the lung adenocarcinoma cell line SK‐LU‐1 as well as the cervical cancer cell line HeLa were determined. Compounds 1 and 2 exhibit cytotoxic activity, whereas compounds 3 and 4 are inactive. Copyright © 2008 John Wiley & Sons, Ltd.     

neo‐Clerodane Diterpenoids from the Aerial Part of Scutellaria barbata

Three new neo‐clerodane diterpenoids, barbatellarines C–E ( 1 – 3 ), were isolated from the CHCl₃‐soluble fraction of the aerial part of Scutellaria barbata. Their chemical structures were elucidated by detailed analysis of NMR and MS data. Compounds 1 and 2 were C(13) epimers, which was confirmed by an NOE difference experiment and the NOESY spectrum. The relative configuration was determined on the basis of the ¹H‐NMR J‐value and NOE data, while the absolute configuration of the previously isolated analogue, barbatellarine B ( 4 ), as a representative member of the group, was assigned by CD analysis.     

Synthesis,Characterization and Migration of Ionic Polyferrocenyl Compounds of 5‐Ferrocenyl‐1H‐tetrazole and Their Effects During Combustion

Eighteen ionic polyferrocenyl compounds with 5‐ferrocenyl‐1H‐tetrazolate as anion and mono‐ and dinuclear ferrocenyl‐alkylammonium as cations were synthesized and characterized by ¹H NMR, ¹³C NMR, FT‐IR, and UV/Vis spectroscopy, and elemental analysis. Molecular structures of three compounds were further confirmed by single‐crystal X‐ray diffraction. Their thermal stability was evaluated by TG and DSC and found that they are of high thermal stability. The cyclic voltammetry analysis suggested that each of the compounds exhibits only an irreversible redox wave of the ferrocene units in the molecule. Both migration and volatility test results showed that, on comparison with those of Catocene, all tested compounds exhibit much more excellent anti‐migration ability and most of the tested compounds have lower volatility. Their effects on the thermal disintegration of ammonium perchlorate (AP), 1,3,5‐trinitro‐1,3,5‐triazacyclohexane (RDX), and 1,2,5,7‐tetranitro‐1,3,5,7‐tetraazacyclooctane (HMX) were measured by DSC. The results revealed that most of the compounds exhibit significant catalytic effects on the thermal degradation of AP and RDX. Particularly, most of the compounds containing one ferrocene unit in their cations show higher activity than that of Catocene. These compounds can be used as alternatives to Catocene in the composite solid propellants.     

Bipolarolides A–G: Ophiobolin‐Derived Sesterterpenes with Three New Carbon Skeletons from Bipolaris sp. TJ403‐B1

Bipolarolides A–G ( 1 – 7 ), seven novel ophiobolin‐derived sesterterpenes with three new types of skeletons, were characterized from fungus Bipolaris sp. TJ403‐B1. Their structures were determined via spectroscopic analyses, X‐ray crystallography, and quantum chemical ¹³C NMR and electronic circular dichroism (ECD) calculations. Compounds 1 and 2 were uniquely defined by a multicyclic caged oxapentacyclo[9.3.0.0^1,6.0^5,9.1^8,12]pentadecane‐bridged system. Compounds 3 and 4 featured an unprecedented 5‐5‐5‐5‐fused core skeleton, while 3 also contained an unexpected C‐3–C‐14 oxygen bridge to construct the caged architecture. Compounds 5 – 7 form a new class of highly modified pentacyclic oxaspiro[4.4]nonane‐containing sesterterpene‐alkaloid hybrids. Their biosynthetic pathways and potential HMG‐CoA reductase inhibitory and antimicrobial activities are also discussed.     

Synthesis and biological activities of a novel series of 3,6‐disubstituted‐1,2,4‐triazolo‐[3,4‐b]‐1,3,4‐thiadiazoles containing gem‐dimethylbenzyl moiety

A novel series of 3,6‐disubstituted‐1,2,4‐triazolo‐[3,4‐b]‐1,3,4‐thiadiazoles (6a–r) containing gem‐dimethyl benzyl moiety were prepared by the condensation of 4‐amino‐3‐aryl/aralkyl substituted‐5‐mercapto‐1,2,4‐triazoles ( 5a , 5b , 5c ) with various fluoro substituted aromatic acids in the presence of POCl₃. IR, ¹H NMR, ¹³C NMR, 2D NMR (COSY), and mass spectral data confirmed the structures of all the synthesized compounds. All the compounds were also screened for their antibacterial, antifungal and analgesic activities. Compounds 6b , 6d , 6f , 6g , 6h , 6i , 6m , 6n , 6o , 6p , and 6r exhibited promising antibacterial and compounds 6a , 6d , 6f , 6g , 6h , 6k , 6m , 6o , 6p , and 6q showed significant analgesic activities. J. Heterocyclic Chem., (2011)     

Three New, 1‐Oxygenated ent‐8,9‐Secokaurane Diterpenes from Croton kongensis

Three new ent‐8,9‐secokaurane diterpenes, kongensins A–C ( 1 – 3 ), were isolated from the aerial parts of Croton kongensis, together with two known compounds, rabdoumbrosanin ( 4 ) and (7α,14β)‐7,14‐dihydroxy‐ent‐kaur‐16‐en‐15‐one ( 5 ). The structures of the new compounds were elucidated by HR‐MS as well as in‐depth 1D‐ and 2D‐NMR analyses. Compounds 1 – 3 showed an unusual oxygenation pattern, with an AcO or OH group at C(1), in combination with a Δ⁸⁽¹⁴⁾ unsaturation ( 1 ) or an 8,14‐epoxide function ( 2, 3 ).     

Phosphoramides: Synthesis,Spectroscopy, and X‐ray Crystallography

A series of new phosphoramides with general formula RP(O)X₂, where R = amino/p‐methylphenoxy and X = amine, were synthesized and characterized by ¹H, ¹³C, ³¹P nuclear magnetic resonance (NMR), and infrared (IR) spectroscopy and elemental analysis. The ³¹P{¹H} NMR spectra show that among compounds 7–9 containing 2‐, 3‐, and 4‐aminopyridinyl moieties, respectively, the shielding order of the P atom decreases as 7 > 9 > 8 . Also, the structure of compound 7 was determined by X‐ray crystallography. In this structure, repeated noncentrosymmetric dimers are formed by two strong intermolecular N(1)‐H(1N)…N(2) and N(3)‐H(3N)…O(1) hydrogen bonds. Taking into account weak intermolecular C(17)‐H(17C)…N(4), C(17)‐H(17E)…N(4), C(2)‐H(2A)…O(2), and also weak aromatic C—H…C interactions, a three‐dimensional polymeric chain is created in the crystalline network. The density functional theory calculations at B3LYP, B3PW91, and M06 levels using the 6–31+G** basis set were in good agreement with the X‐ray crystallography data.     

The synthesis,structural characterization and biological evaluation of N‐(ferrocenylmethyl amino acid) fluorinated benzene‐carboxamide derivatives as potential anticancer agents

A series of N‐(ferrocenylmethyl amino acid) fluorinated benzene‐carboxamide derivatives 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i and 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i have been synthesized by coupling ferrocenylmethyl amine 3 with various substituted N‐(fluorobenzoyl) amino acid derivatives using the standard N‐(3‐dimethylaminopropyl)‐N′‐ethylcarbodiimide hydrochloride, 1‐hydroxybenzotriazole protocol. The amino acids employed in this study were glycine and L‐alanine. All of the compounds were fully characterized using a combination of ¹H NMR, ¹³C NMR, ¹⁹F NMR, distortionless enhancement by polarization transfer (DEPT)‐135, ¹H–¹H correlation spectroscopy (COSY) and ¹H–¹³C COSY (heteronuclear multiple‐quantum correlation) spectroscopy. The compounds were biologically evaluated on the oestrogen‐positive MCF‐7 breast cancer cell line. Compounds 4g , 4i , 5h and 5i exhibited cytotoxic effects on the MCF‐7 breast cancer cell line. N‐(Ferrocenylmethyl‐L‐alanine)‐3,4,5‐trifluorobenzene‐carboxamide ( 5h ) was the most active compound, with an IC₅₀ value of 2.84 μm . Compounds 4i , 5h and 5i had lower IC₅₀ values than that found for the clinically employed anticancer drug cisplatin (IC₅₀ = 16.3 μm against MCF‐7). Guanine oxidation studies confirmed that 5h was capable of generating oxidative damage via a reactive oxygen species‐mediated mechanism. Copyright © 2013 John Wiley & Sons, Ltd.     

Ruthenium N‐heterocyclic–carbene catalyzed diarylation of arene C?H bond

Novel ruthenium‐1,3‐dialkylimidazolin‐2‐ylidene complexes ( 2a–e ) have been prepared and characterized by C, H, N analysis, ¹H‐NMR and ¹³C‐NMR. The ortho position of the aromatic ring of pyridyl group substituted aromatic compound was directly arylated with aryl bromides and chlorides in the presence of a catalytic amount of [RuCl₂(1,3‐dialkylimidazolin‐2‐ylidene)] complexes. Copyright © 2008 John Wiley & Sons, Ltd.     

Alkyl‐Tethered Bis‐Phosphoryl Compounds with two 1,3,2‐Benzodiazaphosphorinone Units; Oxidation,Complexation, and X‐Ray Structure Analysis of Selected Compounds

The reaction of the bis‐chlorophosphines 1 a – 1 d with bis(2‐chloroethyl)amine hydrochloride in the presence of triethylamine and with various trimethylsilylamines led to a new class of bis‐phosphorus ligands 2 a – 2 c and 3 a – 3 g . ³¹P‐NMR studies suggested that the bis‐phosphorus ligands undergo rotation reactions about the alkyl bridge in polar solvents. Compounds 2 a – 2 c showed initially only one sharp singlet each in their ³¹P‐NMR spectra. After a few days at room temperature, two signals were observed. Similar results were observed for 3 a – 3 g . In the solid state, the two phosphorus atoms in 2 c are not equivalent, as was confirmed by the observation of two signals in the solid state ³¹P‐NMR spectrum. Oxidation reactions of 2 a – 2 c by the hydrogen peroxide‐urea 1 : 1 adduct (NH₂)₂C(:O) · H₂O₂ led to the formation of the corresponding phosphoryl compounds 4 a – 4 c . Reaction of 2 a and 3 a with Pt[COD]Cl₂ (COD = 1.5‐Cyclooctadiene) furnished the complexes 5 and 6 . The NMR spectra suggested that the two chlorine atoms are in cis position. X‐ray structure analyses were conducted for 2 a , which exhibits twofold symmetry; 2 c , which is linked into dimers by hydrogen bonds C–H…O; and 6 , confirming the cis configuration.     

Synthesis,spectroscopic/electrochemical characterization and DNA interaction study of novel ferrocenyl‐substituted porphyrins

We report the synthesis and characterization of two new meso‐ferrocenylporphyrins, with the ferrocenyl unit attached at the para position of a C₆F₄ group by a C? N bond with ? NH(CH₂)₂NH? ( 2a ) and ? NH(CH₂)₄NH? ( 2b ) spacers. Compounds 2a and 2b were characterized through elemental analyses, electrospray ionization high‐resolution mass spectrometry, ¹H NMR, UV–visible and fluorescence spectroscopies, electrochemistry and spectroelectrochemistry. The free base porphyrin 2 was included for comparison purposes. The binding ability of 2 and the porphyrin derivatives 2a and 2b with calf thymus DNA was determined using UV–visible and fluorescence spectroscopies. The results suggest that the interaction of these systems most probably occurs through π‐stacking by non‐classical modes involving the partial insertion of the C₆F₅ ring between adjacent base pairs on DNA and possible hydrogen interaction with the aliphatic ? NH(CH₂)_nNH? (n = 2 or 4) groups with calf thymus DNA. Moreover, we also demonstrate that porphyrins generate singlet oxygen species and show good photostability after irradiation.