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17 data found. 1 - 17 listed

Published online: 30th November, 2020

Review | Regular issue | Prepress
DOI: 10.3987/REV-20-944
Highly Oxidized γ-Lactam-Containing Natural Products: Total Synthesis and Biological Evaluation

Kosaku Tanaka III,* Hiroshi Kogen, and Kenichi Kobayashi*

*Graduate School of Pharmaceutical Sciences, Health Sciences University of Hokkaido; 1757 Kanazawa, Tobetsu-cho, Ishikari-gun, Hokkaido 061-0293, Japan

Abstract

γ-Lactam is a ubiquitous structure found in the natural products. A number of highly oxidized γ-lactam-containing natural products are produced by various fungi. These compounds often show a wide range of biological activities because their multiple internal reaction sites, which arise from the high oxidation state of the compounds, can react with biological nucleophiles. Due to their high reactivity and dense functionality, total syntheses of these molecules require strict control of the inherent reactivity and the appropriate design of synthetic intermediates. This review focuses on the recent total syntheses of some highly oxidized γ-lactam-containing natural products, including fused bicyclic (epolactaene, NG-391, lucilactaene, L-755,807), spirocyclic (azaspirene, pseurotin A, E, and F2, cephalimysin A–C, FD-838, and berkeleyamide D), and tricyclic (rubrobramide and talaramide A) skeletons, and on the structure-activity relationship studies of related molecules.

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Published online: 24th November, 2020

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-20-14365
Liquid-Assisted Mechanosynthesis of trans-2,3-Dihydropyrroles from Chalcones and Enaminones

Ming-Yue Weng, Hui Xu,* Hong Chen, and Ze Zhang*

*Anhui Province Key Laboratory of Functional Coordinated Complexes for Materials Chemistry and Application, and School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu 241000, P. R. China

Abstract

An efficient synthesis of a variety of trans-2,3-dihydropyrroles via iodine-promoted cyclization between chalcones and enaminones has been demonstrated under liquid-assisted grinding conditions. The present protocol provides a practical, fast and green alternative to traditional solvent-based methods due to its notable advantages such as significantly higher yield, much shorter reaction time, good functional group tolerance and mild reaction conditions.

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Published online: 18th November, 2020

Paper | Regular issue | Prepress
DOI: 10.3987/COM-20-14363
Probing the Reaction of N,N-Dimethyformamide Dimethyl Acetal with p-tert-Butylthiacalix[4]arene Tetrahydrazides: A Facile Approach for the Synthesis and Application of Novel Metal Receptors

Omran A. Omran and Ayman Nafady*

*Chemistry Department, Faculty of Science, Sohag University, 82524, Sohag, Egypt

Abstract

Recent developments in the field of sensing and recognition revealed that artificial receptors based on calix[4]arenes with π-conjugated fluorophoric or chromophoric moieties are efficient in enhancing selectivity/sensitivity as well as the binding affinity for ionic or molecular recognition. Herein, via studying the reaction of dimethylformamide dimethyl acetal (DMF–DMA) with p-tert-butylthiacalix[4]arene tetrahydrazides in three different conformers (i.e., cone, partial-cone, and 1,3-alternate), the formation of novel lower rim p-tert-butylthiacalix[4]arene derivative (cone, partial-cone, and 1,3-alternate) conformers in high yields (80, 95, and 85%, respectively) was achieved. The structure of isolated products was confirmed using different spectroscopic and analytical techniques such as FT-IR, 1H NMR, 13C NMR, and elemental analysis. Importantly, the synthesized receptors showed preferential uptakes of alkali (Na+, K+ and Cs+), heavy (Pb2+, Cd2+, Hg2+, and Ag+) and transition (Ni2+, Co2+, and Cu2+) metal ions via liquid–liquid extraction method. The finding of this work adds new compounds to the growing family of thiacalix[4]arenes and validates their high sensitivity and selectivity in detection of heavy metal ions.

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Published online: 13th November, 2020

Paper | Regular issue | Prepress
DOI: 10.3987/COM-20-14355
Synthesis, Structures and Interactions with Ct-DNA/BSA of Three New Acylhydrazones Containing Oxazole Ring

Lingling Chang, Xiangrong Liu,* Zaiwen Yang, Shunsheng Zhao, Xinjuan Chen, and Bosen Dai

*College of Chemistry and Chemical Engineering, Xi’an University of Science and Technology, Xi’an 710054, China

Abstract

Three new acylhydrazones containing oxazole ring C11H8N3O2X (X = F, 1; Br, 2; I, 3) have been synthesized. The single crystal XRD presented that 1 belonged to the monoclinic system, while 2 and 3 belonged to the triclinic systems. TG-DTG results showed that the maximum thermal decomposition temperatures of 1-3 were more than 260 °C. The UV-vis spectra, fluorescence spectra and microcalorimetry measurements indicated that each acylhydrazone bound to calf thymus DNA (CT-DNA) via groove binding mode and interacted with bovine serum albumin (BSA) by static quenching effect and the corresponding interaction processes were all exothermic. The molecular docking showed that each acylhydrazone bound to CT-DNA and BSA mainly through hydrogen bonding. The minimum inhibitory concentrations of 1-3 against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa were all about 0.25 mg·mL-1.

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Published online: 13th November, 2020

Paper | Regular issue | Prepress
DOI: 10.3987/COM-20-14356
Practical Synthesis of 1-Substituted 5-Aminopyrazolo[4,3-d]pyrimidin-7-ones Using Intramolecular Friedel–Crafts Type Cyclization and Its Application to the Synthesis of Pharmaceutically Active Compounds

Takashi Goi,* Tetsuji Matsudaira, and Koichi Fukase*

*Sohyaku. Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, 1000, Kamoshida-cho, Aobaku, Yokohama, 227-0033, Japan

Abstract

Intramolecular Friedel–Crafts type cyclization is known as an efficient method of synthesizing fused bicyclic pyrimidones. However, the synthesis of 1-substituted pyrazolo[4,3-d]pyrimidin-7-ones using this cyclization method has not been achieved. Herein, we describe the synthesis of various 1-substituted pyrazolo[4,3-d]pyrimidin-7-ones using practical intramolecular Friedel–Crafts type cyclization, which was carried out in N, N-dimethylformamide in the presence of chlorotrimethylsilane. A hypoxia-inducible factor prolyl hydroxylase domain (HIF-PHD) inhibitor was efficiently synthesized by this method.

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Published online: 12th November, 2020

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-20-14362
A Simple Route for Synthesis and Evaluation of Antioxidant Activity of (Guaiazulen-1-Yl)Furans

Si-Tong Guo, Jiao Xu, Xiao-Liang Zhang, Xin-Shuang Xiong, Lu Zhang, Dao-Lin Wang,* and Shu-Quan Zhang*

*College of Chemistry and Material Science, Bohai University, Jinzhou, China

Abstract

An effective protocol for the synthesis of guaiazulene substituted furan derivatives via three-component reactions of guaiazulene, α-ketoaldehyde, and 1,3-dicarbonyl compound under mild conditions in good yield is reported. All of these compounds were evaluated for their antioxidant properties in vitro against lipid peroxidation and several compounds were found to have good activities.

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Published online: 9th November, 2020

Review | Regular issue | Prepress
DOI: 10.3987/REV-20-943
Systematic Search for Transition States in Complex Molecules: Computational Analyses of the Regio- and Stereoselective Interflavan Bond Formation in Flavan-3-Ols

Daisuke Urabe* and Keisuke Fukaya

*Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan

Abstract

This review describes our recent work on a systematic search for transition states in transformations of complex molecules. The method features a combination of a conformational search method using constrained models to create a large library of transition-state candidates, and subsequent density functional theory (DTF)-based transition state calculations for the candidates. The method is applicable to calculation of transition states for inter- and intramolecular interflavan bond formation in flavan-3-ols to reproduce experimental results for highly regio- and stereoselective C-C bond formation. The specific roles of van der Waals interactions in the transition states can be visualized by NCIPLOT mapping to show the importance of weak but attractive interactions for selective interflavan bond formation.

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Published online: 27th October, 2020

Review | Regular issue | Prepress
DOI: 10.3987/REV-20-939
Attractive Organic Cocrystal Materials in Optics

Xiao Han,* Linyu Wang, and Gaiqing Xi

*College of Chemical Engineering & Material, Hebei Key Laboratory of Heterocyclic Compounds, Handan University, Handan 056005, Hebei, China

Abstract

Since the beginning of this century, organic molecule solid material, one of favorable choices for constructing high-performance optoelectronic devices/circuits, has showed the impressive perspective in organic optoelectronics. Especially, because of the long-range order, absent grain boundary and extremely low defect density, organic single-crystal material support a great platform for fundament and application researches. Herein, cocrystal engineering, one simply collaborative strategy, shows offers the unique advantages, involving facile and low-cost synthesis procedure, easily achieving rare and multifunctional properties, tunable structure, morphology and size. It is extremely suitable to construct functional organic molecule solid material, especially novel multifunctional organic single-crystal materials. In this mini review, a overview of organic cocrystal is presented to introduce its attractive future in optics, such as OFET, lasing, nonlinear optics, optical waveguide material, stimuli-responsive material and other potential applications.

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Published online: 22nd October, 2020

Review | Regular issue | Prepress
DOI: 10.3987/REV-20-940
Synthetic Approaches for Heteroannulated Chromones Fused Various Heterocyclic Systems

Salsabeel H. Hashiem, Magdy A. Ibrahim, Al-Shimaa Badran,* Nasser M. El-Gohary, and Hassan A. Allimony

*Department of Chemistry, Faculty of Education, Ain Shams University, Roxy 11711, Cairo, Egypt

Abstract

The main focus of this review summarized the different methods utilized for the synthesis of chromone annulated with different heterocyclic rings such as pyrroles, furans, pyrazole, imidazole, benzene, naphthalene, quinolone……and others.

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Published online: 21st October, 2020

Review | Regular issue | Prepress
DOI: 10.3987/REV-20-935
The Interrupted Pummerer Reaction: Design of Sulfoxides and Their Utility in Organic Synthesis

Kazuhiro Higuchi* and Masanori Tayu

*Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan

Abstract

Acid anhydride-activated sulfoxides can undergo a variety of cascade reactions after reacting with nucleophiles on its sulfur atom. Originally regarded as an abnormal phenomenon that occurs under Pummerer reaction conditions, the reports of the reaction increased gradually, and research regarding sulfoxide reactivity has advanced. In recent years, the term ‘interrupted Pummerer reaction’ has been introduced, and the transformation has been actively incorporated into the development of new research areas. Such studies have yielded numerous valuable sulfoxides, which contribute to the precise reaction control and to the generation of practical products. Notably, the outcome of the interrupted Pummerer reaction is characteristic for each nucleophile.

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Published online: 20th October, 2020

Review | Regular issue | Prepress
DOI: 10.3987/REV-20-942
Mini Review: Antioxidant Application of Metal-Organic Frameworks and Their Composites

Shaikha S. Alneyadi*

*Department of Chemistry, College of Science, UAE University Al-Ain, 15551 UAE

Abstract

Metal–organic frameworks (MOFs) are porous coordination materials composed of multidentate organic ligands and metal ions or metal clusters. MOFs have great potential as medical materials for biological, environmental, and food antimicrobial fields. In recent years, MOFs have been applied to various antioxidant fields due to their continued release capability, porosity, and structural flexibility in combination with many chemicals and/or materials such as nanoparticles, antioxidant, and polymers. This review offers a detailed summary of the antioxidant applications of MOFs and their composites, focusing on the combination types of MOF composites and their antioxidant effects in different applications described in 2015-2020. These applications are illustrated by the examples discussed in this review.

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Published online: 6th October, 2020

Review | Regular issue | Prepress
DOI: 10.3987/REV-20-941
Synthetic Methods for Phosphorus Compounds Containing Chromone and Thiochromone Rings

Tarik E. Ali,* Mohammed A. Assiri, Somaia M. Abdel-Kariem, and Ibrahim S. Yahia

*Department of Chemistry, Faculty of Education, Ain Shams University, Roxy, Cairo, Egypt

Abstract

The chromone and thiochromone rings are prominent heterocyclic substructures present in numerous natural and pharmacologically active compounds. To date, many chromone analogues containing phosphorus compounds are interest in several laboratories due to their potent pharmacological activities. This review compiles all the available literature data on the synthesis of phosphorus compounds containing chromone and thiochromone rings as well as their available biological properties starting from their appearance up to the end of 2019.

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Published online: 8th September, 2020

Review | Regular issue | Prepress
DOI: 10.3987/REV-20-938
9,9'-Bi(Xanthene)-Type Hexaphenylethane Derivatives as Advanced Organic Electrochromic Systems

Takanori Suzuki,* Yusuke Ishigaki, Masaki Takata, Jun-ichi Nishida, and Takanori Fukushima

*Department of Chemistry, Faculty of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan

Abstract

9-Phenylxanthenyl radical can undergo facile C-C bond formation at C9-position when the two units of the radical are connected at C2'-positions to give stable intramolecular dimer (1), which is a clamped hexaphenylethane derivative with an elongated C-C bond. The newly formed bond in 1 can be cleaved easily upon two-electron oxidation to give bis(9-xanthenylium)-type dication (22+), from which the diradical is generated upon two-electron reduction. This review account describes the dynamic redox ("dyrex") pair of colorless 1 and yellow-orange 22+, which provides a versatile scaffold to develop multi-functional electrochromic systems. Both of 1 and 22+ are sterically challenged molecules and thus adopt characteristic skewed geometries. Electrochiroptical response was realized by suppressing the chiral inversion of helicity in 1 and axial chirality in 22+ whereas redox-induced fluorescence switching was attained by attaching the fluorophore whose emission is quenched by xanthenylium in 22+ but not by spiro(xanthene) unit in 1. By the molecular design that allows intramolecular chiral transmission, the spectral changes were also induced by the external stimuli (e.g. heat, pH) other than redox input, which made it possible to construct less well-explored multi-input-multi-output response systems. More advanced functions could be endowed, such as chiral redox memory or reversible O2-storage, by further modification of the prototype.

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Published online: 20th August, 2020

Review | Regular issue | Prepress
DOI: 10.3987/REV-20-937
Pyrrolotetrazoles and Ring-Fused Derivatives

Dietrich Moderhack*

*Institute of Medicinal and Pharmaceutical Chemistry, Technical University, Braunschweig, Beethovenstrasse 55, D-38106, Germany

Abstract

The preparative chemistry of seven types of pyrrolotetrazoles (formally: pyrrolo[1,2-d]tetrazoles) AG including five ring-fused derivatives such as B', B'', C', C'', and E' is surveyed in this article. Theoretical work on annular tautomerism and pyrrolotetrazole–azidopyrrole isomerism is dealt with complementarily.

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Published online: 18th August, 2020

Review | Regular issue | Prepress
DOI: 10.3987/REV-20-936
An Overview of Quantitative and Qualitative Approaches on the Synthesis of Heterocyclic Kojic Acid Scaffolds through the Multi-Component Reactions

Fatemeh Mohajer and Ghodsi Mohammadi Ziarani*

*Department of Chemistry, Alzahra University, Vanak Square, 1993893973, Tehran, Iran

Abstract

Multi-component reactions as powerful synthetic methods were developed to provide efficient complex scaffolds, including kojic acid, through the one-pot one-step fashion. This review highlights the progress of multicomponent reactions covering kojic acid under different conditions through, short reaction time, higher yields, and environmental friendliness via producing various molecules. The aim of this paper is to review the literature from 2015 to 2020 via quantitative and qualitative approaches.

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Published online: 13th August, 2020

Review | Regular issue | Prepress
DOI: 10.3987/REV-20-933
Recent Development of Stereoselective Glycosylation Reactions

Shino Manabe*

*Laboratory of Functional Molecule Chemistry, Pharmaceutical Department and Institute of Medicinal Chemistry, Hoshi University, 2-4-41 Ebara, Shinagawa, Tokyo, 142-8501, Japan

Abstract

Carbohydrates are the most abundant class among biological molecules. Advances in glycobiology have revealed the vital roles played by glycosides and glycoconjugates in biological events. In this context, access to homogenous oligosaccharides and glycoconjugates is critical for various biological investigations. Glycosylation is the cornerstone of glycoside synthesis, and during glycosylation, the control of stereoselectivity at the anomeric position is highly important. In this review, recent progresses in 1,2-cis-glycosylation reactions are summarized, with a focus on the influence of the protecting groups on the conformations of the glycosyl donors, role of reaction mixture additives, and synthetic utility of endocyclic cleavage of glycoside. Development of robust glycosylation reaction will contribute to biologically active oligosaccharide synthesis.

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Published online: 3rd July, 2020

Review | Regular issue | Prepress
DOI: 10.3987/REV-20-934
Aryne-Mediated Synthesis of Oxygen Heterocycles and Application to Cysteine-Selective Trapping

Hideto Miyabe*

*Laboratory for Medicinal Chemistry, School of Pharmacy, Hyogo University of Health Sciences, 1-3-6 Minatojima, Chuo-ku, Kobe City, 650-8530, Japan

Abstract

The use of arynes as the highly reactive intermediates in organic synthesis has attracted substantial attention. Particularly, the introduction of ortho-(trimethylsilyl)aryl triflates as easily activatable aryne precursors led to growing activity in this field. Most reactions using these aryne precursors proceed through the addition of nucleophiles to arynes and the subsequent trapping with electrophiles to give the multisubstituted arenes with structural diversity and complexity. Based on our studies, this review highlights the insertion of arynes, generated from ortho-(trimethylsilyl)aryl triflates, into C=O π-bond of formamides. Initially, the representative examples for formal [2+2] cycloaddition of arynes with the carbon–heteroatom double bond or the heteroatom–heteroatom double bond are shown. Next, the studies on the insertion of arynes into the N−C and C=O bonds of amide group including our three-component coupling reaction leading to oxygen heterocycles are summarized. The SN2’ reaction of tricyclic oxygen heterocycles, obtained by three-component coupling reaction, was studied by using carbon and sulfur nucleophiles. The SN2’ reaction was expanded to four-component coupling reaction. Finally, the application of tricyclic oxygen heterocycles to cysteine-selective trapping is described.

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17 data found. 1 - 17 listed