http://www.mdpi.com/journal/molecules/special_issues/heterocycles/ We will run this special issue again in 2008. Manuscripts should be prepared according to the Instructions for Authors and submitted by e-mail before 30 May 2008 to molecules@mdpi.org and a copy to mcphee@mdpi.org. The subject title of the message should be "Molecules Manuscript for Special Issue on Heterocycles". http://www.mdpi.com/1420-3049/13/4/938/ The conversion from kobophenol A into carasinol B, two main chemicalconstituents of Caragana sinica, was confirmed by in vitro acid-catalyzed epimerization.The result provides important information about the biotransformation of kobophenol A inplants and its metabolism in rats. http://www.mdpi.com/1420-3049/13/4/938/ Sat, 19 Apr 2008 00:00:00 CEST Molecules 2008-04-19 13 4 Communication 938 942 1420-3049 Acid-catalyzed Epimerization of Kobophenol A to Carasinol B 2008-04-19 doi: 10.3390/molecules13040938 Kejun Cheng Gaolin Liang Changqi Hu http://www.mdpi.com/1420-3049/12/8/1940/ This paper reports the preparation, characterization and the crystal X-ray structures of metal-containing ionic liquid complexes based on chiral pyridinium cations and tetrachloropalladate (II) [PdCl4]2-. http://www.mdpi.com/1420-3049/12/8/1940/ Mon, 20 Aug 2007 00:00:00 CEST Molecules 2007-08-20 12 8 Article 1940 1949 1420-3049 Palladate Salts from Chiral Pyridinium Ionic Liquids: Synthesis and Crystal Structures 2007-08-20 doi: 10.3390/12081940 Emmanuel Tourneux Heinz Gornitzka Jean-Daniel Marty Nancy Lauth-de Viguerie http://www.mdpi.com/1420-3049/12/8/1623/ 2,3-Dicyano-5,7-bismethylthieno[3,4-b]pyrazine (5), has been obtained as a minor product from reactions of S-nucleophiles with 5,6-di(1-bromoethyl)pyrazine-2,3- dicarbonitrile (3), or from a condensation of 4-hydroxy-2,5-dimethyl-2,3-dihydrothiophen- 3-one (4) with diaminomaleonitrile. The molecular structure of compound 5 has been confirmed by X-ray diffraction. A partial separation of charge causes a donor-acceptor type arrangement of the planar molecules in uniform parallel stacks with an interplanar spacing of 3.334(2) Å at 100 K. http://www.mdpi.com/1420-3049/12/8/1623/ Mon, 30 Jul 2007 00:00:00 CEST Molecules 2007-07-30 12 8 Article 1623 1631 1420-3049 o-Quinonoid Heterocycles: Synthesis and Crystal Structure of 2,3-Dicyano-5,7-bismethylthieno[3,4-b]pyrazine 2007-07-30 doi: 10.3390/12081623 Eva H. Mørkved Jon A. Beukes Frode Mo http://www.mdpi.com/1420-3049/12/7/1482/ A novel approach to the synthesis of pyrazole derivatives from tosylhydrazones of α,β-unsaturated carbonyl compounds possessing a β-hydrogen is proposed, exploiting microwave (MW) activation coupled with solvent free reaction conditions. The cycloaddition was studied on three ketones (trans-4-phenyl-3-buten-2-one, β-ionone and trans-chalcone). The corresponding 3,5-disubstitued-1H-pyrazoles were obtained in high yields and after short reaction times. In order to simplify and point out the green chemistry features of the method, a further improvement was achieved under the same catalytic conditions with a “one pot” synthesis of these heterocyclic compounds, starting directly from their carbonyl precursors via tosylhydrazones generated in situ. For an exhaustive study, the dielectric properties of the solid reaction mixtures were also measured, in order to obtain input data for the numerical simulation of their heating behaviour in the single mode MW cavity which was used for experimental work. In order to supply a valid methodology and tool for measuring the environmental impact, a comparative study between the synthetic route proposed and the classical synthetic route has been carried out. http://www.mdpi.com/1420-3049/12/7/1482/ Thu, 19 Jul 2007 00:00:00 CEST Molecules 2007-07-19 12 7 Article 1482 1495 1420-3049 New “Green” Approaches to the Synthesis of Pyrazole Derivatives 2007-07-19 doi: 10.3390/12071482 Anna Corradi Cristina Leonelli Antonino Rizzuti Roberto Rosa Paolo Veronesi Romano Grandi Sara Baldassari Carla Villa http://www.mdpi.com/1420-3049/12/7/1389/ The newly synthesized 5,10,15,20-tetra[3-(3-trifluoromethyl)phenoxy]porphyrin, TTFMPP, has been characterized using mass spectroscopy, 1H-, 13C- and 19F-NMR, MALDI-TOF mass spectrometry, UV-Vis and fluorescence spectrophotometry, andcyclic voltammetry. The NMR confirmed the structure of the compound and the massspectrum was in agreement with the proposed molecular formula. The UV-Vis absorptionspectrum of TTFMPP shows characteristic spectral patterns similar to those of tetraphenylporphryin, with a Soret band at 419 nm and four Q bands at 515, 550, 590, and 648 nm.Protonation of the porphyrin with TFA resulted in the expected red shift of the Soret band.Excitation at 419 nm gave an emission at 650 nm. The quantum yield of the porphyrin wasdetermined to be 0.08. Cyclic voltammetry was used to determine the oxidation andreduction potentials of the new porphyrin. Two quasi-reversible one-electron reductions at–1.00 and –1.32 V and a quasi-reversible oxidation at 1.20 V versus the silver/silverchloride reference electrode with tetrabutylammonium tetrafluoroborate as the supportingelectrolyte in methylene chloride were observed. http://www.mdpi.com/1420-3049/12/7/1389/ Wed, 11 Jul 2007 00:00:00 CEST Molecules 2007-07-11 12 7 Article 1389 1398 1420-3049 Atmospheric Pressure Microwave Assisted Heterogeneous Catalytic Reactions 2007-07-11 doi: 10.3390/12071389 Cynthia P Tidwell Prakash Bharara Gretchen Rudeseal Tiffany Rudeseal Frank H Rudeseal Christine A Simmer Dugald McMillan Katherine Lanier L Dalila Fondren LaTasha L Folmar Ken Belmore http://www.mdpi.com/1420-3049/12/5/1183/ Five optically active imidazole derivatives have been synthesized via a facile 4-step reaction sequence starting from commercially available and inexpensive N-Cbz amino acids. While microwave assisted condensation was unsuccessful, the condensation of the corresponding α-bromoketones with formamidine acetate in liquid ammonia was revealed to be a useful method for the synthesis of such imidazole derivatives. The derivatives thus prepared are structurally-related to histamine. http://www.mdpi.com/1420-3049/12/5/1183/ Wed, 30 May 2007 00:00:00 CEST Molecules 2007-05-30 12 5 Article 1183 1190 1420-3049 Facile Synthesis of Optically Active Imidazole Derivatives 2007-05-30 doi: 10.3390/12051183 Ales Marek Jiri Kulhanek Miroslav Ludwig Filip Bures http://www.mdpi.com/1420-3049/12/4/703/ Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants of the terrestrial environment that have been designated as Environmental Protection Agency (EPA) Priority Pollutants. In this study, molecular modeling was used to examine the physical and chemical characteristics of soil organic matter (SOM), fulvic acid (FA) and humic acid (HA), as well as their binding interactions with PAHs. The molecular structures of 18 PAHs were built by using the SYBYL 7.0 program and then fully optimized by a semiempirical (AM1) method. A molecular docking program, AutoDock 3.05, was used to calculate the binding interactions between the PAHs, and three molecular structure models including FA (Buffle’s model), HA (Stevenson’s model) and SOM (Schulten and Schnitzer’s model). The π-π interactions and H-bonding interactions were found to play an important role in the intermolecular bonding of the SOM/PAHs complexes. In addition, significant correlations between two chemical properties, boiling point (bp) and octanol/water partition coefficient (Log Kow) and final docking energies were observed. The preliminary docking results provided knowledge of the important binding modes to FA, HA and SOM, and thereby to predict the sorption behavior of PAHs and other pollutants. http://www.mdpi.com/1420-3049/12/4/703/ Thu, 05 Apr 2007 00:00:00 CEST Molecules 2007-04-05 12 4 Article 703 715 1420-3049 Investigation on the Binding of Polycyclic AromaticHydrocarbons with Soil Organic Matter: A Theoretical Approach 2007-04-05 doi: 10.3390/12040703 Patchreenart Saparpakorn Jae Hyoun Kim Supa Hannongbua http://www.mdpi.com/1420-3049/12/3/634/ 5-Acetoxymethyl- and 5-hydroxymethyl-2-vinylfuran were synthesized by two routes. The first route starts from 2-methylfuran and the second from furfuryl acetate. The latter route, involving successive Vilsmeier-Haack and Wittig reactions, is suitable for producing 5-acetoxymethyl-2-vinylfuran and 5-hydroxymethyl-2 vinylfuran in 68% and 60%yields, respectively. http://www.mdpi.com/1420-3049/12/3/634/ Mon, 26 Mar 2007 00:00:00 CEST Molecules 2007-03-26 12 3 Article 634 640 1420-3049 Synthesis of 5-Acetoxymethyl- and 5-Hydroxymethyl-2-vinyl-furan 2007-03-26 doi: 10.3390/12030634 Alexander Mehner Ana L Montero Ricardo Martinez Stefan Spange http://www.mdpi.com/1420-3049/12/3/504/ Selenium-containingheterocyclic compounds have been well recognized, not only because of their remarkable reactivities and chemical properties, but also because of their diverse pharmaceutical applications. In this context, isoselenocyanates have been emerged as a powerful tool for the synthesis of selenium-containing heterocycles, since they are easy to prepare and store and are safe to handle. In this review the recent advances in the development of synthesis methods forselenium-containing heterocycles from isoselenocyanates are presented and discussed. http://www.mdpi.com/1420-3049/12/3/504/ Sat, 17 Mar 2007 00:00:00 CET Molecules 2007-03-17 12 3 Review 504 535 1420-3049 Isoselenocyanates: A Powerful Tool for the Synthesis of Selenium-Containing Heterocycles 2007-03-17 doi: 10.3390/12030504 Dinesh Ramesh Garud Mamoru Koketsu Hideharu Ishihara http://www.mdpi.com/1420-3049/12/3/353/ Four new diterpenoid alkaloids: tiantaishansine (1), tiantaishannine (2), tiantaishanmine (3), and tiantaishandine (4) have been isolated from the roots of Delphinium tiantaishan. Their structures were elucidated by chemical evidence andspectral analyses, including ESI-MS, HR-EI-MS, 1D- and 2D-NMR. http://www.mdpi.com/1420-3049/12/3/353/ Thu, 08 Mar 2007 00:00:00 CET Molecules 2007-03-08 12 3 Article 353 360 1420-3049 New Diterpenoid Alkaloids from the Roots of Delphinium tiantaishanense 2007-03-08 doi: 10.3390/12030353 Jie Li Dong-Lin Chen Xi-Xian Jian Feng-Peng Wang http://www.mdpi.com/1420-3049/12/2/255/ Synthesis of 3,1,5-benzoxadiazepines from the condensation of o-phenylenediamine (o-PDA) and acyl chlorides in the presence of a catalytic amount of various heteropolyacids (HPAs) is reported. http://www.mdpi.com/1420-3049/12/2/255/ Mon, 26 Feb 2007 00:00:00 CET Molecules 2007-02-26 12 2 Article 255 262 1420-3049 Heteropolyacids as Green and Reusable Catalysts for the Synthesis of 3,1,5-Benzoxadiazepines 2007-02-26 doi: 10.3390/12020255 Majid M. Heravi Samaheh Sadjadi Hossein A. Oskooie Rahim Hekmat Shoar Fatemeh F. Bamoharram