HETEROCYCLES

■ Contents

■ Transition-Metal-Catalyzed Borylation of Organic Halides with Hydroboranes

Miki Murata*

*Department of Materials Science and Engineering, Kitami Institute of Technology, Koen-cho 165, Kitami, Hokkaido 090-8507, Japan

Abstract

Metal-catalyzed cross-coupling reaction of B–H compounds provides a direct method for conversion of C–X bonds to C–B bonds. Dialkoxyboranes are excellent boron sources in the borylation of aryl, 1-alkenyl, allyl or benzyl halides or pseudohalides. These reactions tolerate large number of functional groups and proceeds with excellent yields, thereby allowing the simple, convenient, and elegant preparation of functionalized C–B compounds.

■ Design and Synthesis of Novel Opioid Ligands and Their Pharmacologies

Hiroshi Nagase* and Hideaki Fujii

*School of Pharmaceutical Sciences, Kitasato University, 5-9-1, Shirokane, Minato-ku, Tokyo 108-8641, Japan

Abstract

We describe the recent progress of our investigations in the opioid field in this review, which includes interesting reactions using naltrexone derivatives and pharmacological properties of the synthesized derivatives. Some reactions utilized the characteristic structural features of the morphinan skeleton, and others were applicable to general compounds. Some derivatives were expected to be lead compounds for developing novel ligands selective for the individual opioid receptor types. Triplet drugs consisting of three pharmacophore units in one molecule exhibited interesting pharmacological profiles and would be expected to be a useful tool for clarifying the pharmacology of receptor oligomerization.

■ Development of the Acenaphthenequinone Reactions

Ghodsi Mohammadi Ziarani,* Parvin Hajiabbasi, and Parisa Gholamzadeh

*Department of Chemistry, Alzahra University, Vanak Square, Tehran, P.O. Box number 19938939973, Iran

Abstract

Acenaphthenequinone and its derivatives have a broad spectrum of applications as biologically active compounds, dyes, pharmaceuticals, drugs, therapeutic agents and pesticides. This brief review represents various reactions such as pericyclic, multicomponent, ring opening and substitutions of acenaphthenequinone reactions.

■ Microwave-Assisted Synthesis of 2-Aminopyrimidines from Silica Gel-Adsorbed Propargyl Alcohols and Guanidine

Qing-Zhen Chen, Zong-Cang Ding, Yan-Li Ma, Zhen-Dong Wang, and Zhuang-ping Zhan*

*College of Chemistry and Chemical Engineering, Department of Chemistry, Xiamen University, 422 Siming Nanlu, Xiamen, Fujian 361005, China

Abstract

A novel methodology toward the synthesis of 2-aminopyrimidines has been developed. The silica gel adsorbed propargyl alcohols and guanidine easily give the corresponding 2-aminopyrimidines under microwave irradiation.

■ Design, Synthesis and Biological Activity Evaluation of 2-Mercapto-4(3H)-quinazolinone Derivatives as Novel Inhibitors of Protein Tyrosine Phosphatase 1B

Hui Li, Jin-Ping Wang, Fan Yang, Ting Liu, Wen-Wei Qiu, Jing-Ya Li, Jia Li,* and Jie Tang*

*Department of Chemistry, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China

Abstract

A series of novel 2-mercapto-4(3H)-quinazolinone derivatives have been synthesized and their inhibitory effects on PTP1B and TCPTP are evaluated for the first time. Most of these derivatives showed good inhibitory activity on PTP1B and reasonable selectivity for PTP1B over TCPTP, among them 32 was the most potent PTP1B inhibitor (IC50 = 1.50 μg/mL), and 27 possessed the best selectivity of 3.0-fold.

■ Synthesis of Some New Pyridine-2,6-bis-heterocycles

Korany A. Ali, Mohamed A. Elsayed, and Ahmad M. Farag*

*Department of Chemistry, Faculty of Science, Cairo University, Giza 12613, Egypt

Abstract

The versatile multifunctional hitherto unreported pyridine-2,6-bis[ethyl 2-(N,N-dimethylamino)methylene-3-oxopropanoate] (2) was prepared by the reaction of pyridine-2,6-bis(ethyl 3-oxopropanoate) (1) with 1,1-dimethoxytrimethylamine. Several new pyrazole, isoxazole, pyrimidine, pyrazolo[1,5-a]pyrimidine, and imidazo[1,2-a]pyrimidine derivatives attached to pyridine ring at 2,6-positions have been synthesized by the reactions of the enaminone 2 with the appropriate nitrogen binucleophiles.

■ Aurone Constituents from the Flowers of Rosa rugosa and Their Biological Activities

Xuemei Gao, Liying Yang, Lidang Shu, Yanqiong Shen, Yinjie Zhang,* and Qiufen Hu*

*Key Laboratory of Ethnic Medicine Resource Chemistry, State Ethnic Affairs Commission & Ministry of Education, School of Chemistry and Biotechnology, Yunnan University of Nationalities, Kunming 650031, China

Abstract

Three new aurones, rugaurones A–C (1-3), together with four known aurones (4-7) were isolated from the flowers of Rosa rugosa. Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D- NMR techniques. Compounds 1-7 were tested for their anti-HIV-1 activity and cytotoxicities. The results showed that compound 3 has significant potential anti-HIV-1 activity, compounds 2 have high cytotoxic abilities, and other compounds also have moderate biological activities.

■ Synthesis and Evaluation of 4-Aryl-2(1H)-quinolinones as Potent Amyloid β Fibrillogenesis Inhibitors

Yoko Shimokawa, Masamichi Nakakoshi, Setsu Saito, Hideharu Suzuki, Yuusaku Yokoyama, Akihito Ishigami, Hideo Nishioka, and Masayoshi Tsubuki*

*Institute of Medicinal Chemistry, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan

Abstract

4-Aryl-2(1H)-quinolinones were synthesized and evaluated in vitro as inhibitors of Aβ1-42 fibrillogenesis using a thioflavin T fluorescence method. The most potent anti-aggregating molecules (4b and 5c) were found among the derivatives bearing OH and/or OMe groups at C-4’ (R4) and/or C-6 (R2) of the 4-aryl-2(1H)-quinolinone moiety. Furthermore, the derivative bearing 4’-F substituent (4f) proved to be a very active inhibitor.

■ Facile One-Pot Procedure for the Synthesis of 2-Aminothiazole Derivatives

Guodong Yin,* Junrui Ma, Houqiang Shi, and Qing Tao

*Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, College of Chemistry and Environmental Engineering, Hubei Normal University, Huangshi 435002, Hubei, China

Abstract

A facile, efficient synthesis of 2-aminothiazole derivatives by the reaction of easily available aromatic methyl ketones with thiourea/N-substituted thioureas in the presence of copper(II) bromide was developed. The reaction underwent a one-pot α-bromination/cyclization process.

■ New Indole Alkaloids from Melodinus henryi

Mariko Kitajima, Satoko Ohara, Noriyuki Kogure, Yuqiu Wu, Rongping Zhang, and Hiromitsu Takayama*

*Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan

Abstract

Two new indole alkaloids, melodinoxanine (1) and Nb-methylnortetraphyllicine (2), were isolated from the stems and leaves of Melodinus henryi growing in Yunnan, China. Melodinoxanine (1) is a unique oxindole alkaloid with an extra oxygen atom in the C-ring of a heteroyohimbine skeleton.

■ Absolute Configuration of the Meroditerpenoids Taondiol and Epitaondiol Diacetates by Vibrational Circular Dichroism

Marcelo A. Muñoz, Carlos Areche, Juana Rovirosa, Aurelio San Martín, Bárbara Gordillo-Román, and Pedro Joseph-Nathan*

*Departamento de Química, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, A.P. 14-740, Avenida IPN 2508, Esquina Ticoman, C.P. 07000 México, D.F., Mexico

Abstract

The absolute configuration of alga meroditerpenoids (–)-taondiol diacetate (1b) and (+)-epitaondiol diacetate (2c) are assigned by vibrational circular dichroism (VCD). The spectra of (2S,3S,6R,7R,10R,11R,14S)-1b and (2S,3S,6S,7S,10R,11R,14S)-2c enantiomers, calculated at the B3LYP/DGDZVP and at the B3LYP/DGDZVP2 levels of theory, respectively, matched confidently with the experimental ones. The numerical approach using neighborhood similarity indexes in the CompareVOA algorithm software supports the assignments with 100% confidence. The X-ray diffraction structures of 1b and 2c were determined to verify their relative stereochemistry and the crystal stereostructure of the meroditerpenoid stypotriol triacetate (5) is also reported.

■ Synthesis of Pyridine-2,6-bis-((E)-2-benzylidene-3-oxopropanenitrile) and Its Behavior towards Nitrogen Binucleophiles

Korany A. Ali*

*Department of Applied Organic Chemistry, National Research Center, Dokki, Cairo 12622, Egypt

Abstract

Several new pyrazole, isoxazole and pyrimidine derivatives attached to pyridine ring at 2,6-positions have been synthesized by the reactions of the versatile multifunctional unreported pyridine-2,6-bis((E)-2-benzylidene-3-oxopropanenitrie) (2a) with several nitrogen binucleophiles. A novel one-pot three-component reaction of an aldehyde, pyridine-2,6-bis(3-oxopropanenitrile) (1) and electron-rich heterocyclic amines including [3-phenyl-1H-pyrazol-5-amine (12) and 2-aminobenzimedazole (16)] in DMF have been described.

■ Synthesis and Structure and Optical Properties of a Zinc(II) Tetrakis(phenylbutadiynyl)porphyrin

Liu-tao Yang, Di Wu,* Hai-feng Xiang, Xiangge Zhou, and Yue-fei Deng*

*College of Chemistry, Sichuan University, 610064 Chengdu, China

Abstract

A porphyrin complex, zinc(II) tetrakis(phenylbutadiynyl)porphyrin, is constructed through meso-substitution approach, which exhibits remarkable bathochromism in absorption and fluorescent spectrum. Both the Q bands in the absorption spectrum and the emission band are red-shifted to the saturated red region. The theoretical analysis showed that the meso-phenylbutadiynyl groups significantly extended the π-conjugation from the porphyrin core to the meso aryl groups.

■ A Convenient Synthesis of 2-Arylthiochromen-4-ones (Thioflavones) by Iodine-Mediated Cyclization of 3-Aryl-1-[2-(1,1-dimethylethylsulfanyl)phenyl]prop-2-en-1-ones

Kazuhiro Kobayashi,* Akihiro Kobayashi, and Kosuke Ezaki

*Division of Applied Chemistry, Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama-minami, Tottori 680-8552, Japan

Abstract

A convenient two-step synthesis of 2-arylthiochromen-4-ones (thioflavones) beginning with 1-[2-(1,1-dimethylethylsulfanyl)phenyl]ethanones is described. Thus, 3-aryl-1-[2-(1,1-dimethylethylsulfanyl)phenyl]prop-2-en-1-ones were prepared by the condensation of 1-[2-(1,1- dimethylethylsulfanyl)phenyl]ethanones with aromatic aldehyde in the presence of sodium hydroxide, and were treated with iodine in refluxing N-methylpyrrolidin-2-one (NMP) or propanenitrile to afford the desired products in moderate to fair yields.

■ Corrigendum to “Antitumoral Alkaloids from Clausena lansium” : HETEROCYCLES, 2010, 81, 1261

Wisanu Maneerat and Surat Laphookhieo*

*Applied Chemistry Program, School of Science, Mae Fah Luang University, 333 Moo 1, Tasud, Muang 57100, Thailand