Synthesis of Some N1-(3-Hydroxy-2-pyridyl)benzamides

Benzoxazoles are of special interest because of having various types of biological properties such as antihistaminic, antihelmintic antifungal and antibacterial activities. ¹ Hisano, T., Ichikawa, M., Tsumoto, K. and Tasaki, M. 1982. Chem. Pharm. Bull, 30: 2996 [CSA][Crossref], [Web of Science ®] , [Google Scholar], ² Prudhomme, M., Guyot, J. and Jeminet, G. 1986. J. Antibiotics, 39: 934 [CSA][Crossref], [PubMed], [Web of Science ®] , [Google Scholar], ³ Ersan, S., Nacak, S., Berkem, R. and Özden, T. 1997. Arzneim. Forsch, 47: 963 [CSA][PubMed], [Web of Science ®] , [Google Scholar], ⁴ Sener, E., Yalc?n, ?., Temeiz, Ö., Ören, ?., Ak?n, A. and Ucartürk, N. 1997. Farmaco, 52: 99 [CSA][PubMed] , [Google Scholar], ⁵ Ören, ?., Temiz, Ö., Yalc?n, ?., Sener, E., Ak?n and Ucartürk, N. 1997. Forsch, 47: 1393 [CSA] [Google Scholar], ⁶ Temiz, Ö., Ören, ?., Sener, E., Yalc?n, ?. and Ucartürk, N. 1998. Farmaco, 53: 337 [CSA][CROSSREF][Crossref], [PubMed] , [Google Scholar], ⁷ Yalc?n, ?., Ören, ?., Sener, E., Ak?n, A. and Ucartürk, N. 1992. J. Med. Chem, 27: 401 [CSA][CROSSREF][Crossref], [Web of Science ®] , [Google Scholar], ⁸ Temiz, Ö., Ören, ?. and Altanlar, N. 2002. Farmaco, 57: 175 [CSA][CROSSREF][Crossref], [PubMed] , [Google Scholar], ⁹ Sener, E., Temeiz, Ö., Yalc?n, ?. and Altanlar, N. 2000. Farmaco, 55: 397 [CSA][CROSSREF][Crossref], [PubMed] , [Google Scholar], ¹⁰ Ören, ?., Temiz, Ö., Yalc?n, ?., Sener, E. and Altanlar, N. 1998. Eur. J. Pharm. Sci., 7: 153 [CSA][Crossref], [Web of Science ®] , [Google Scholar] Benzamide derivatives, as the possible metabolites of benzoxazoles, show various types of biological activities. ¹¹ Sener, E., Bingöl, K., Ören, ?., Arpac?, Ö., Yalc?n, K. ?. and Altanlar, N. 2000. Farmaco, 55: 469 [CSA][CROSSREF][Crossref], [PubMed] , [Google Scholar], ¹² Sener, E., Yalc?n, K. ?. and Altanlar, N. 2002. Farmaco, 57: 451 [CSA][CROSSREF][Crossref], [PubMed] , [Google Scholar] Some N-(2-hydroxyphenyl)- benzamides, which showed significant activity compared to phenylacetamides and furamides,11 have been synthesized by treating 2-aminophenol with carboxylic acid chlorides under weak basic solution. ¹¹ Sener, E., Bingöl, K., Ören, ?., Arpac?, Ö., Yalc?n, K. ?. and Altanlar, N. 2000. Farmaco, 55: 469 [CSA][CROSSREF][Crossref], [PubMed] , [Google Scholar], ¹² Sener, E., Yalc?n, K. ?. and Altanlar, N. 2002. Farmaco, 57: 451 [CSA][CROSSREF][Crossref], [PubMed] , [Google Scholar] However, synthesis and especially biological activity of N-(3-hydroxy-2-pyridyl)benzamides were not studied well. Owing to the versatility of benzamides we have extended the reaction of 2-amino-3-pyridinol with different carboxylic acid chlorides in order to preparation of some new benzamide derivatives containing a hydroxypyridyl ring.     

Synthesis and Characterization of a New Dioxime and Its Heterotrinuclear BF2 + Capped Complexes

ω‐Isonitrosoacetophenone 1 Uçan, H. ? and Mirzao?lu, R. 1990. Synth. React. Inorg. Met.‐Org. Chem., 20: 437[Taylor & Francis Online], [Web of Science ®] , [Google Scholar], phenylglyoxime 2 Burakevich, J. V., Lore, A. M. and Volpp, G. P. 1971. J. Org. Chem., 36: 1[Crossref], [Web of Science ®] , [Google Scholar], chlorophenylglyoxime 1 Uçan, H. ? and Mirzao?lu, R. 1990. Synth. React. Inorg. Met.‐Org. Chem., 20: 437[Taylor & Francis Online], [Web of Science ®] , [Google Scholar], dopaminophenylglyoxime 3 Uysal, ?., Co?kun, A., Koç, Z. E., Uçan, M. and Uçan, H. ?. 2007. R. J. Coord. Chem., 33: 351–357. [Crossref] , [Google Scholar] and [(salen/saloph)Fe]₂O 4 Kopel, P., Sindelar, Z. and Klicka, R. 1998. Trans. Met. Chem., 23: 139[Web of Science ®] , [Google Scholar] have been synthesized as described in the literature procedure. [Fe(III)(salen/saloph)dopaminophenylglyoxime)] (starting complexes) have been synthesized from dopaminophenylglyoxime and tetradentate schiff bases which contain dinuclear Fe(III) oxygen‐bridges N,N′‐bis(salicylidene)ethylenediamine (salenH₂) and bis(salicylidene)‐o‐phenylenediamine (salophH₂). The new heterotrinuclear complexes have been obtained from starting complexes and Co(II), Ni(II), Cu(II) salts. Then, heterotrinuclear vic‐dioxime complexes containing BF₂ ⁺ capped have been synthesized. The complexes have been characterized as low‐spin distorted octahedral Fe(III) bridged by o‐hydroxyphenolic groups. The o‐hydroxyphenolic groups play a role as bridges for weak antiferromagnetic intramolecular exchange. The structure of dioxime and its complexes were identified by using elemental analysis, ICP‐AES, ¹H‐NMR and IR spectral data.     

α,α‐Dibromoketones: A Superior Alternative to α‐Bromoketones in Hantzsch Thiazole Synthesis

Abstract

α,α‐Dibromoketones (2) have been found to be a superior alternative to the conventionally used α‐bromoketones (1) for performing the Hantzsch thiazole synthesis.1 Ahluwalia, V. K., Mehta, B. and Rawat, M. 1992. Synth. Commun., 22: 2697[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar] These crystalline, nonlachrymatory compounds are more reactive than 1 as demonstrated by their reaction with 3,5‐dimethyl‐1‐thiocarboxamide (5).     

Chloro complexes of cobalt(II) in aprotic solvents: stability and structural modifications due to solvent effect

Cobalt(II) chloro complexes were studied in aprotic solvents, namely, dimethylsulfoxide (DMSO), dimethylformamide (DMF), and propylene carbonate (PC). The measurements were performed spectrophotometrically in UV–visible–IR region at 25°C and at constant ionic strength: I = 1 mol L^?1 in DMSO and DMF, and 0.1 mol L^?1 in PC. Different models were tested and the model 1 Elleb, M, Meullemeestre, J, Schwing, MJ and Vierling, F. 1980. Inorg. Chem., 19: 2699[Crossref], [Web of Science ®] , [Google Scholar], 2 Elleb, M, Meullemeestre, J, Schwing, MJ and Vierling, F. 1982. Inorg. Chem., 21: 1477[Crossref], [Web of Science ®] , [Google Scholar], 3 Khan, MA, Meullemeestre, J, Schwing, MJ and Vierling, F. 1983. Polyhedron, 2: 459[Crossref], [Web of Science ®] , [Google Scholar], 4 Amuli, C, Meullemeestre, J, Schwing, MJ and Vierling, F. 1983. Inorg. Chem., 22: 3567[Crossref], [Web of Science ®] , [Google Scholar], i.e., that of four mononuclear successive complexes was retained. Stability constants of the identified complexes were determined and they increase inversely with the Gutmann's donor number of the solvents. Calculated electronic spectra are reported and the effect of solvents on the spectral properties are discussed. The symmetry of tetrachlorocobaltate is strictly T_d.     

The Effect of the Electron Density Distribution of Guest on the Entropy Change During Complex Formation of Calix[6]arene Hexasulfonate Host with ortho- and para-cresols as Guests

The π–π interaction-based inclusion complexation of calix[6 Danil de Namor, A. F., Cleverly, R. M. and Zapata-Ormachea, M. L. 1998. Chem. Rev., 98: 2495[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]]arene hexasulfonate as host with neutral aromatic guest molecules was studied in aqueous media. To vary the distribution of electron density on the guest's aromatic rings, the phenol parent compound was substituted in the para- or ortho- positions with CH₃ group. To study the interaction between calixarene and the guests, PL, DSC and quantum-chemical methods were used. The results indicate 1:1 stoichiometry of the formed host-guest complexes. Although the enthalpy change during complex formation of calixarene with p- or o-cresol are the same, the Gibbs free energy change is significantly higher in the case of calixarene—o-cresol complexes. This property is due to the unexpected entropy change during the complex formation. Using molecular dynamic calculations, a guest-induced redistribution of the electron density on the calixarene rings, followed by the restructuring of the solvent molecules was identified as a background of this unexpected entropy change at molecular level.     

Synthesis of New α-Heterocyclic α-Aminophosphonates

α-heterocyclic α-aminophosphonates were obtained in good yields by N-of several nitrogen heterocycles with α-azido-α-aminophosphonate 1. ¹ Elachqar, A., El Hallaoui, A., Roumestant, M. L. and Viallefont, Ph. 1994. Synthetic Comm, 24: 1279 [CSA][Taylor & Francis Online], [Web of Science ®] , [Google Scholar]     

Host (nanopores of zeolite-Y)/guest (Co(II)-azamacrocyclic complexes) nanocomposite materials: synthesis,characterization and catalytic epoxidation of styrene with molecular oxygen

A series of Co(II) azamacrocyclic complexes, 12 Brunel, D, Bellocq, N, Sutra, P, Cauvel, A, Lasperas, M, Moreau, P, Di Renzo, F, Galarneau, A and Fajula, F. 1998. Coord. Chem. Rev., 178–180: 1085[Crossref], [Web of Science ®] , [Google Scholar]aneN₄, 14 De Vos, DE, Dams, M, Sels, BF and Jacobs, PA. 2002. Chem. Rev., 102: 3615[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]aneN₄, Bzo₂ 12 Brunel, D, Bellocq, N, Sutra, P, Cauvel, A, Lasperas, M, Moreau, P, Di Renzo, F, Galarneau, A and Fajula, F. 1998. Coord. Chem. Rev., 178–180: 1085[Crossref], [Web of Science ®] , [Google Scholar]aneN₄ and Bzo₂ 14 De Vos, DE, Dams, M, Sels, BF and Jacobs, PA. 2002. Chem. Rev., 102: 3615[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]aneN₄, have been encapsulated in the nanocavity of zeolite-Y by a one pot template condensation reaction. Co(II) complexes with azamacrocyclic ligands were entrapped in the nanocavity of zeolite-Y by a two-step process in the liquid phase: (i) adsorption of [bis(diamine)cobalt(II)], [Co(N–N)₂]-NaY, in the supercages of the zeolite, and (ii) in situ condensation of the cobalt(II) precursor complex with diethyloxalate. The new host/guest nanocomposite materials (HGNM) have been characterized by FTIR, DRS and UV-Vis spectroscopic techniques, XRD and elemental analysis, as well as nitrogen adsorption. These complexes (neat and HGNM) were used for epoxidation of styrene with O₂ as oxidant in different solvents. Electronic spectra of the reaction mixture indicated oxidation proceeds through a free radical mechanism.     

Three-component reactions of phosphorus ylides,thiophenols, and acetyl chloride for the synthesis of (β-thioacrylates)

The facile synthesis of β-thioacrylates has been realized via direct three-component reactions of thiophenols, Wittig reagents, and acetyl chloride. Under transition metal-free conditions, a class of β-thioacrylates have been synthesized with fair to excellent yields via cascade C=C double bond and C(sp² Kano, T.; Shirozu, F.; Akakura, M.; Maruoka, K. J. Am. Chem. Soc. 2012, 134, 16068-16073.[Crossref], [PubMed], [Web of Science ®] , [Google Scholar])-S bond formation.     

SYNTHESIS OF HIGHLY SUBSTITUTED 1,6-NAPHTHYRIDINES: A REINVESTIGATION

ABSTRACT

A reinvestigation of the recently described method of synthesis of highly substituted 1,6-naphthyridines was carried out. It was found out that the reaction of chalcones with malononitrile catalysed by pyrrolidine afforded the mixture of four products both when thermal as well as microwave heating was used. The claimed[1] Murugan, P., Raghukumar, V. and Ramakrishnan, V.T. 1999. Synth. Commun., 29: 3881–3386. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar] 1,6-naphthyridines formation were exceptions.     

CYCLIC PHOSPHONITRILIC COMPOUNDS BEARING ─N═PCl3 GROUP AS HOMOGENOUS CATALYST TOWARDS THE SILANOL CONDENSATION

Condensation reactions of 1,1,3,3,3 pentamethyldisiloxane-ol (MDH), in toluene catalysed by two[9.5pc] types of phosphonitrilic catalyst bearing a phosphazene ─N═PCl₃, were studied using sampling and gas chromatographic analysis method. The condensation kinetics reactions were compared for both phosphazene compounds. The process is selective, leading to linear decamethyltetrasiloxane MD₂M, (where D denotes the dimethylsiloxane unit and M denotes the trimethyloxysilane unit) as almost the exclusive primary product. The mechanisms of the MDH condensation are discussed using the ³¹ Allcock, H. R. and Ngo, D. 1992. Macromolecules, 25: 2802[Crossref], [Web of Science ®] , [Google Scholar]P NMR sampling technique.     

DFT calculations,microsynthesis and characterization of isopropyl methylphosphonoselenofluoridate [sarin-Se]

Abstract

Isopropyl methylphosphonoselenofluoridate (sarin-Se) was synthesized in order to determine its analytical data and to compare them as well as its reactivity parameters with those of sarin. After synthesis, sarin-Se was characterized using ¹ Mesilaakso, M. In: Mesilaakso, M. (Ed.), Introduction, Chemical Weapons Convention Analysis, Sample Collection, Preparation and Analytical Methods, Wiley, Chichester, 2005.[Crossref] , [Google Scholar]H, ¹³ Rayman, M. P.; Infante, H. G.; Sargent, M. Food-Chain Selenium and Human Health: spotlight on Speciation. Br. J. Nutr. 2008, 100, 238–253.[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]?C and ³¹P NMR spectroscopy and high resolution mass spectrometry (HRMS). ¹ Mesilaakso, M. In: Mesilaakso, M. (Ed.), Introduction, Chemical Weapons Convention Analysis, Sample Collection, Preparation and Analytical Methods, Wiley, Chichester, 2005.[Crossref] , [Google Scholar]H and ¹³ Rayman, M. P.; Infante, H. G.; Sargent, M. Food-Chain Selenium and Human Health: spotlight on Speciation. Br. J. Nutr. 2008, 100, 238–253.[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]?C NMR chemical shifts were also calculated using density functional theory (DFT) and compared with experimental data, showing a close agreement. Electrophilicity indices of sarin and sarin-Se were calculated at B3LYP/6-31++G (2d, 2p) level of theory. HOMO-LUMO analysis provides a basis to explain electrophilic nature of sarin-Se and sarin, which are almost similar. Based on calculated data, ³¹P NMR chemical shift and the reactivity of sarin-Se towards some enzymes such as acetylcholinesterase and albumin were explained.     

Dicopper complex of p-tert -butylcalix8arene bearing acylhydrazone pendant domains

A dicopper complex of p-tert-butylcalix8 Atwood, JL, Barbour, LJ, Hardie, MJ and Raston, CL. 2001. Coord. Chem. Rev., 222: 3[Crossref], [Web of Science ®] , [Google Scholar]arene bearing eight salicylaldehyde acylhydrazone domains was prepared and its single crystal structure determined, in which only four acylhydrazone domains act as monoanionic tridentate planar chelators to coordinate to two copper ions.     

Investigation of Combined Effects of Xanthan Gum,Sodium Dodecyl Sulphate,and Salt on Some Physicochemical Properties of Their Mixtures Using a Response Surface Method

Aqueous solutions containing sodium dodecyl sulphate, xanthan gum, and salt were characterized by ionic conductivity, viscosity, and surface tension methods. A preliminary experimental study was performed to evaluate the effect of the mixture compositions on the surface behavior of the mixed polymer/surfactant systems under different solution conditions. An experimental design using response surface method (RSM) was then applied to assess factors interactions and empirical models regarding the physicochemical responses variables (i.e., conductivity, surface tension and viscosity). The main effects of the three independent factors: SDS concentration (x₁), NaCl concentration (x₂) and xanthan concentration (x₃) were determined using in particular a D-optimal design. The results show an important effect of the factors on responses; they also indicate that the synergetic action of surfactant, electrolyte and biopolymer greatly influences these properties. Analysis of variance (ANOVA) showed high variance coefficient (R ² Avarnas , A. and Panagiotis , I. ( 2003 ) J. Colloid Int. Sci. , 258 : 102 – 109 .[Crossref], [Web of Science ®] , [Google Scholar]) values, thus, ensuring a satisfactory adjustment of the second-order regression model with the experimental data.     

Bivalent Organophosphorus Compounds—Synthesis and Acetylcholinesterase Inhibitory Activity

Abstract

A series of novel symmetric S,S′-2,2′-(ethane-1,2-diylbis(azanediyl)) bis(2-oxoethane-2,1-diyl) O,O,O′,O′-tetraethyl diphosphorodithioate derivatives (12) was designed and synthesized based on the cluster effect and the multiple binding sites of acetylcholinesterase (AChE). The structures of all the newly synthesized title compounds were characterized by ¹ Choi, S. K. Synthetic Multivalent Molecules: Concepts and Biomedical Application, 20–21. New Jersey: John Wiley & Sons, Inc. 2004, chapter 1 [Google Scholar]H and ¹³ Tang, H., Zhao, L. Z., Zhao, H. T., Huang, S. L., Zhong, S. M., Qin, J. K., Chen, Z. F., Huang, Z. S. and Liang, H. 2011. Euro. J. Med. Chem., 46: 4970–4979. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]C NMR as well as elemental analyses. Their inhibitory activities against AChE were tested, and compound 12b exhibited the best activity (6.60-fold higher than ethion). The results suggested that the compound would bind to the catalytic center and the narrow gorge of the AChE simultaneously.

Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional table.     

[2]Benzothiophene bent-shaped liquid crystals

New liquid crystalline (LC) compounds containing the [2 Weissflog, W., Nádasi, H., Dunemann, U., Pelzl, G., Diele, S., Eremin, A. and Kresse, H. 2001. J. Mater. Chem., 11: 2748–2758. [Crossref], [Web of Science ®] , [Google Scholar]]benzothiophene chromophore unit have been synthesised and their mesomorphic properties studied. Mesomorphic and fluorescent properties have been modified by various chemical moieties. Among others, terminal fluoroalkyl and/or chiral chains were introduced to stabilise mesophases and support the formation of polar phases. In spite of the bent shape due to the central 1,3-diphenylbenzo[c]thiophene unit, all compounds exhibit phases typical for the rod-like LC: nematic, smectic A and smectic C or their chiral analogues using the chiral (S)-C₂H₅CH(CH₃)(CH₂)₆CO or (S)-C₁₀H₂₁OCH(CH₃)CO chain. The orientational order in the nematic phase was studied by polarised infrared measurements. The fluorescent properties of the studied compounds have been measured and their parameters established.     

Heterocyclic polycatenar liquid crystals

We report the synthesis of polycatenar liquid crystals incorporating 2,5‐disubstituted 1 O’Neill, M. and Kelly, S. M. 2003. Adv. Mater., 15: 1135[Crossref], [Web of Science ®] , [Google Scholar] 3 Catry, C., van der Auweraer, M., de Schryver, F. C., Bengs, H., Häussling, K., Karthaus, O. and Ringsdorf, H. 1993. Makromol. Chem., 194: 2985[Crossref] , [Google Scholar] 4 Adam, D., Schumacher, P., Simmerer, J., Häussling, K., Siemensmeier, K., Etzbach, K. H., Ringsdorf, H. and Haarer, D. 1994. Nature., 371: 141[Crossref], [Web of Science ®] , [Google Scholar]‐oxadiazole and 1 O’Neill, M. and Kelly, S. M. 2003. Adv. Mater., 15: 1135[Crossref], [Web of Science ®] , [Google Scholar] 3 Catry, C., van der Auweraer, M., de Schryver, F. C., Bengs, H., Häussling, K., Karthaus, O. and Ringsdorf, H. 1993. Makromol. Chem., 194: 2985[Crossref] , [Google Scholar] 4 Adam, D., Schumacher, P., Simmerer, J., Häussling, K., Siemensmeier, K., Etzbach, K. H., Ringsdorf, H. and Haarer, D. 1994. Nature., 371: 141[Crossref], [Web of Science ®] , [Google Scholar]‐thiadiazole rings joined by a combination of carbon–carbon single and double bonds (–CH = CH–). The ratio of the aromatic core to the aliphatic chains was varied systematically by changing the number of the aliphatic chains, from two to six, and their length, from short to very long, i.e. from methoxy to hexadecyloxy. The shape anisotropy of the core was varied by exchanging the oxygen atom in the 1 O’Neill, M. and Kelly, S. M. 2003. Adv. Mater., 15: 1135[Crossref], [Web of Science ®] , [Google Scholar] 3 Catry, C., van der Auweraer, M., de Schryver, F. C., Bengs, H., Häussling, K., Karthaus, O. and Ringsdorf, H. 1993. Makromol. Chem., 194: 2985[Crossref] , [Google Scholar] 4 Adam, D., Schumacher, P., Simmerer, J., Häussling, K., Siemensmeier, K., Etzbach, K. H., Ringsdorf, H. and Haarer, D. 1994. Nature., 371: 141[Crossref], [Web of Science ®] , [Google Scholar]‐oxadiazole for a sulfur atom to form the corresponding 1 O’Neill, M. and Kelly, S. M. 2003. Adv. Mater., 15: 1135[Crossref], [Web of Science ®] , [Google Scholar] 3 Catry, C., van der Auweraer, M., de Schryver, F. C., Bengs, H., Häussling, K., Karthaus, O. and Ringsdorf, H. 1993. Makromol. Chem., 194: 2985[Crossref] , [Google Scholar] 4 Adam, D., Schumacher, P., Simmerer, J., Häussling, K., Siemensmeier, K., Etzbach, K. H., Ringsdorf, H. and Haarer, D. 1994. Nature., 371: 141[Crossref], [Web of Science ®] , [Google Scholar]‐thiadiazole ring with a smaller deviation from coaxiality of the bonds in the 2,5‐positions. The shape anisotropy of the core was increased by the presence of an additional phenylenevinylene unit in a series of tetracatenar oxadiazoles. We report the synthesis, physical properties and polymerization of a polycatenar reactive mesogen in a columnar phase to form a polycatenar polymer network.     

New N-Substituted (E)-4-Arylidene Isoquinoline-1,3-dione Derivatives: NMR Spectroscopic Investigation and Antibacterial Activity

Abstract

New N-substituted 4-arylidene-isoquinoline-1,3-dione derivatives were obtained as one geometrical isomer by aldol condensation of the appropriate aldehyde and the corresponding N-substituted homophthalimides. The structural elucidation of compounds 3a–h was established by infrared and NMR spectroscopy including ¹ Dimmock , J. R. ; Wong , M. L. C. Bioactivities and potential uses in drug design of acyclic α,β-unsaturated ketones . Can. J. Pharm. Sci. 1976 , 11 , 35 – 53 .[Web of Science ®] , [Google Scholar]H, ¹³ Perjési , P. ; Szabó , D. ; Batta , G. ; Földesi , A. The stereochemistry of reaction of 2-benzylidenecyclohexanone with dithiocarbamic acid . Tetrahedron Lett. 1987 , 28 , 571 . [Google Scholar]C, CH CORR, and distortionless enhancement by polarization transfer measurements. Compounds 3d–h were evaluated for their antibacterial activity against some strains of bacteria using the disc diffusion method and microdilution tests.     

Synthesis,X-ray structure,and DFT studies of five- and eight-coordinated Cd(II) complexes with s-triazine N-pincer chelate

Abstract

The synthesis and spectral characterizations of [CdLCl₂] (1 C. J. Moulton, B.L. Shaw. J. Chem. Soc. Dalton Trans., 1020 (1976).[Crossref] , [Google Scholar]) and [CdL(NO₃)₂(H₂O)] (2 G. van Koten. Pure Appl. Chem., 61, 1681 (1989).[Crossref], [Web of Science ®] , [Google Scholar]) pincer complexes of the s-triazine core ligand (L), 2,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine), are presented. Complexes 1 and 2 have five- and eight-coordinated Cd(II) ions, respectively, where L acts as a neutral tridentate N-chelate. The coordination sphere is completed by two coordinated Cl^– anions in 1 and with one water molecule and two bidentate nitrate anions in 2. The neutral complex units of 1 and 2 are packed by the polar Cl…H and O…H hydrogen bonds, respectively. Using Hirshfeld analysis, the percentages of these contacts are 24.5% and ～36.8%, respectively. Both complexes showed some anion-π stacking interactions. Thermogravimetric analysis showed that 1 is thermally more stable than 2. The orbital-orbital interactions included in the Cd-Cl, Cd-O, and Cd-N coordinate bonds were analyzed using DFT calculations. The calculated NMR results correlated very well with the experimental data.     

Optically active tertiary alcohols by biocatalysis

Initially, chemoenzymatic route to optically active aromatic ring-fused cyclic tertiary alcohols (S)-(–)-1-methyl-1,2,3,4-tetrahydronaphthalen-1-ol-(–)-1b, (S)-(+)-1-methyl-2,3-dihydro-1H-inden-1-ol-(+)-1a has been reported.^[9 Özdemirhan, D.; Sezer, S. Sönmez, Y. Tetrahedron Asymmetry 2008, 19(23), 2717–2720.[Crossref], [Web of Science ®] , [Google Scholar]^] CAL-A (lipase-A from Candida antarctica) was found the best biocatalyst for 1b, CAL-A cross linked enzyme aggregate (CLEA) for 1a, with ee values of 20 and 45% and the esters 2b and 2a with ee values 99 and 71%. Then, cyclopent-2-ene anchored tertiary allyl 1a′, homoallyl 1b′ and homopropargyl 1c alcohols have been enzymaticly resolved in a high ee (up to 90%) with 44, 40, and 43% chemical yield, respectively, cyclohex-2-ene anchored tertiary allyl 3a, homoallyl 3b, and homopropargyl 3c alcohols in high ee (up to 97%) too with 42, 45, and 49% chemical yield in turn. Chiral dienes yield the spirocyclic dihydropyrans through ring-closing methathesis with 74 and 78% chemical yields with 90 and 97% ee. Chiral enynes afford the cyclopentenone pyrans through Pauson–Khand reaction with 80 and 81% chemical yields as single diastereomers as reported subsequently.^[1a (a) Tanyeli, C.; Özdemirhan, D. Tetrahedron Asymmetry 2014, 25(8), 658–666; (b) Gassoline, F.; Britton, R. A.; Mowat, J.; O’shea, P. D.; Davies, I. W. Synlett 2007, 14, 2193–2196; (c) Garcia, C.; Martin, V. S. Curr. Org. Chem. 2006, 10(14), 1849–1889; (d) Fujino, A.; Asano, M.; Yamaguchi, H.; Shirasaka, N.; Sakoda, A.; Ikunaka, M.; Obata, R.; Nishiyama, S.; Sugai, T. Tetrahedron Lett. 2007, 48(6), 979–983.[Crossref], [Web of Science ®] , [Google Scholar]^]     

Silica Gel Promotes Cascade Synthesis of 2-(Heteroaryl)acetamide Derivatives from Isocyanides,Dialkylamines, and Heteroarylcarbaldehydes

Abstract

Addition of an isocyanide to an iminium ion intermediate that forms from the reaction between a heteroarylcarbaldehyde and a secondary amine leads to formation of sterically congested 2-(heteroaryl)acetamide derivatives in the presence of silica gel at room temperature. The structures of the products were deduced from their ¹ Tietze , L. F. ; Modi , A. Multicomponent domino reactions for the synthesis of biologically active natural products and drugs . Med. Res. Rev. 2000 , 20 , 304 .[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]H NMR, ¹³ Ugi , I. ; Steinbrückner , C. Über ein neues Kondensations-Prinzip . Angew. Chem. 1960 , 72 , 267 .[Crossref], [Web of Science ®] , [Google Scholar]C NMR, and infrared spectra and mass spectrometry.