Prepress

Regular & Special Issues

15 data found. 1 - 15 listed

Published online: 3rd October, 2022

Paper | Regular issue | Prepress
DOI: 10.3987/COM-22-14736
■ An Efficient Catalyst-Free Synthesis of Vinyl Sulfides in Aqueous-Phase

Jiewei Rong and Haiying Wang*

*School of Chemistry & Materials Science, Jiangsu Normal University, Xuzhou 221116, P. R. China

Abstract

An efficient catalyst-free synthesis of vinyl sulfides via the Michael addition of thiol compounds and tetrolic acid ester (or methyl propiolate) in water were carried out in good yields. The products were identified by IR, 1H NMR and HRMS techniques. The structures of 5b, 6b and 8a were confirmed by X-ray diffraction analysis further. This protocol has the advantages of shorter reaction time, mild conditions, easy work-up and environmental friendliness.

FREE:Supporting Info. (740KB)PDF (605KB)

Published online: 29th September, 2022

Paper | Regular issue | Prepress
DOI: 10.3987/COM-22-14743
■ Ultrasound-Promoted Kabachnik–Fields Synthesis of Novel Chromonyl α-Aminophosphonate Derivatives Incorporating Nitrogen Heterocycles Using CdI2 Nanoparticles as an Efficient Catalyst: Evaluation of Their Antifungal Properties

Mohamed Hussien,* Tarik E. Ali, Ibrahim El-Tantawy El Sayed, Abdelaleem Hassan Abdelaleem, and H. M. Torkey

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

Abstract

Synthesis of some novel chromonyl α-aminophosphonate esters clubbed with nitrogen heterocycles, was achieved. The methodology based on one-pot three-components reaction of 4-oxo-4H-chromene-3-carboxaldehydes, N-aminoheterocycles and diethyl phosphite in the presence of CdI2 nanoparticles as an efficient catalyst under conventional heating at 80 oC or ultrasound (US) irradiation at 50 oC. The mild reaction conditions, operational simplicity and excellent yields are the essential advantages of this protocol. The antifungal properties of the products were evaluated. Most of them recorded inhibitory effects towards plant pathogenic fungi nearly to the standard control. The hybridization between diethyl α-aminophosphonate and 6-methylchromone moieties with antipyrine, morpholine or 1,2,4-triazine in one molecular frame led to promising antifungal agents against plant pathogenic fungi.

FREE:PDF (617KB)

Published online: 27th September, 2022

Paper | Regular issue | Prepress
DOI: 10.3987/COM-22-14708
■ Synthesis and Utilization of Tetrahydronaphthalene-1,3-dicarbonitrile as a Source of Benzo[f]quinazoline, Pyridine, Imidazole Derivatives with Antitumor Activity and Molecular Docking and Dynamics Studies

Marwa El-Hussieny, Fatma A. A. El-Hag, Ahmed A. El-Rashedy, and Ewies F. Ewies*

*Organometallic and Organometalloid Chemistry Department, National Research Centre, ElBohouth St., Dokki, Giza, Egypt

Abstract

Seventeen new compounds of benzo[f]quinazoline, pyridine, and imidazole derivatives were prepared via reaction of 2-amino-4-phenyl-5,6,7,8-tetrahydronaphthalene-1,3-dicarbonitrile (1) with carbon disulfide, urea, thiourea, formic acid, formamide, acetonitrile, acetic anhydride, phenyl isocyanate, phenyl isothiocyante, and triethyl orthofromate followed by cyclization with hydrazine hydrate to give pyrimidine derivatives 2-10. Besides that, reaction of compound 1 with 2-benzylidenemalononitrile or with ethyl acetoacetate afforded pyridine derivatives 11 and 12. Also, compound 1 reacted with ethylenediamine or o-phenylenediamine to give imidazole derivatives 13a-d. Structures of the isolated new products were elucidated by compatible analytical and spectroscopic measurements. Moreover, antitumor activity of all new compounds is studied. Compound 3b is the most active compound among these derivatives against two cancer cell lines (MCF7, HepG2) in comparison with Doxorubicin as a reference drug. Computational modeling of studied DNA-ligands systems reveals that 3b compound can potentially inhibit DNA dodecamerd target thereby creating a pathway toward DNA targeting approach in the anticancer treatment.

FREE:Supporting Info. (1.3MB)PDF (653KB)

Published online: 27th September, 2022

Paper | Regular issue | Prepress
DOI: 10.3987/COM-22-14740
■ A Transition Metal-Free System for C3-H Nitrosation of Imidazo[1,2-α]pyridine Using Sodium Nitrite at Room Temperature

Liting Yang, Ya Chen, Kun Zhao, Hongyi Zhou, Qiaochu Zhang, Chunxia Qin, Baiwei Ma, Dehong Yang, Haiyan Yang, Guoqun Liu,* Huijie Qiao,* and Liwei Mi*

*School of Materials and Chemical Engineering, Henan Key Laboratory of Functional Salt Materials, Zhongyuan University of Technology, 41 Zhongyuan Middle Road, Zhengzhou City, Henan Province, China

Abstract

Most current strategies for the direct nitrosations (nitrosylations) of imidazo[1,2-a]pyridines employ NaNO2/AcOH system, which generally need low temperatures to ensure safety and suffer acidic conditions, or flammable, explosive tert-butyl nitrite, which releases toxic gases when heated, as the NO source. Therefore, a novel strategy to prepare these 3-nitrosoimidazo[1,2-a]pyridines is necessary. Here, a transition metal-free C3–H nitrosation of imidazo[1,2-a]pyridine was developed using low-cost, stable NaNO2 as the nitrosylation source in the presence of K2S2O8 at room temperature under an air atmosphere. Imidazo[1,2-a]pyridine derivatives with different substituents were efficiently converted to their respective nitrosylation products in moderate-to-good yields under mild conditions via ion processes. Moreover, the successful gram-scale reaction and post-synthetic transformations reveal the potential of this strategy for application in industrial production, drug synthesis, and other fields.

FREE:Supporting Info. (3.4MB)PDF (1MB)

Published online: 21st September, 2022

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-22-14711
■ Inhibition of Amyloid-β Aggregation by p-Terphenyls from the Mushroom Polyozellus multiplex and Their Neuroprotective Effects

Shoko Nakabayashi, Ayaka Ishikura, Koji Fujihara, Shuntaro Hirabayashi, Shin Koike, Hiroaki Sasaki, Yuki Ogasawara, Kiyotaka Koyama, and Kaoru Kinoshita*

*Department of Pharmacognosy and Phytochemistry, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan

Abstract

The main pathogenesis of Alzheimer’s disease (AD) is related to the accumulation of amyloid- (A) peptides in the brain that leads to neuronal cell death. In this study, we identified compounds in a methanol extract of the fruiting body of Polyozellus multiplex that inhibited A aggregation and are neuroprotective. Seven compounds against A40 aggregation were obtained through bioactivity-guided fractionation of the extract, including polyozellin (1), kynapcin-12 (2), NSC617425 (3), cycloleucomelone (4), Bl-V (5), succinic acid (6), and protocatechuic acid (7). Compounds 1–5 inhibited A40 aggregation in a dose-dependent manner. Moreover, compounds 2–5 protected SH-SY5Y cells from Atoxicity. Therefore, these compounds are potential agents in AD treatment.

FREE:Supporting Info. (1.9MB)PDF (707KB)

Published online: 20th September, 2022

Paper | Regular issue | Prepress
DOI: 10.3987/COM-22-14738
■ Synthetic Approaches for Construction of Novel Angular Heterocyclic Systems Containing Chromeno[2,3-b]quinoline

Magdy A. Ibrahim,* Sami A. Al-Harbi, Esam S. Allehyani, Esam A. Alqurashi, and Fatmah M. Alshareef

*Department of Chemistry, Faculty of Education, Ain Shams University, Roxy 11757, Cairo, Egypt

Abstract

Cyclic β-chloroenaldehyde 1 was used to create a novel series of angular heteroannulated chromones. Condensation of β-chloroenaldehyde 1 with hydrazine derivatives produced chromeno[2,3-b]pyrazolo[3,4-f]quinolines 2, 5 and 6. Also, condensation of compound 1 with some 1,3-N,N-binucleophiles yielded chromeno[2`,3`:6,5]pyrido[2,3-h]quinazolines 7-9. Treating compound 1 with some 1,3-N,C-binucleophiles produced chromeno[2,3-J]phenanthrolines 10, 11, benzoimidazo[1,2-a]chromeno[2,3-J]phenanthroline 12 and chromeno[2,3-J]- pyrazolo[3,4-b]phenanthrolines 13, 14. Reacting compound 1 with a diversity of 1,4-binucleophiles produced chromeno[2,3-b][1,4]diazepino[2,3-f]quinoline 15, chromeno[2,3-b][1,4]benzodiazepino[2,3-f]quinoline 16, chromeno[2,3-b][1,4]- benzoxazepino[2,3-f]quinoline 17 and chromeno[2,3-b][1,4]benzothiazepino- [2,3-f]quinoline 18. The in vitro antimicrobial activity seemed variable inhibitory effect for the prepared compounds.

FREE:PDF (338KB)

Published online: 16th September, 2022

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-22-14737
■ Synthesis of New Multivalent Furo[3,2-c]pyridine and Bifuro[3,2-c]pyridine Derivatives

Maurice Taszarek and Hans-Ulrich Reissig*

*Institut für Chemie und Biochemie, Freien Universität Berlin, Takustr. 3 Berlin, Germany

Abstract

A series of furo[3,2-c]pyridine derivatives was prepared by an efficient cascade process involving Sonogashira reactions of 4-hydroxy-3-iodopyridine with suitable terminal alkynes followed by an immediate 5-endo-dig cyclization to generate the furan ring. Several multivalent furo[3,2-c]pyridines were prepared by employing dialkynes or trialkynes. Two bifuro[3,2-c]pyridine derivatives were prepared by alternative coupling methods. The photophysical properties of several of these compounds are compared.

FREE:Supporting Info. (131KB)PDF (737KB)

Published online: 14th September, 2022

Paper | Regular issue | Prepress
DOI: 10.3987/COM-22-14735
■ Regiodivergent Medium-Ring Oxasilacycle Synthesis from Diallylsilanes

Inna A. Fomina, Christopher R. Myers, Cierra L. M. Soumis, Margaret L. Scheuermann, James McCarty, Timothy B. Clark, and Gregory W. O'Neil*

*Chemistry, Western Washington University, MS 9150, 516 High Street, U.S.A.

Abstract

Medium-ring (7-9 membered) oxasilacycles were synthesized by sequential electrophile-promoted rearrangement of diallylsilanes, etherification with an alkene-containing alcohol, and ring-closing metathesis (RCM). Depending on the choice of catalyst for the RCM, different oxasilacycle products could be obtained. The first-generation catalyst cleanly afforded allyl ether oxasilacycles whereas the second-generation Grubbs catalyst selected for the regioisomeric cyclic enol ether, resulting from RCM followed by isomerization. Isomerization during RCM was suppressed by substitution at the allyl ether position. The use of homoallyl ether- or non-ether substrates, and/or the addition of benzoquinone also prevented isomerization during RCM, suggestive of a ruthenium hydride-based double bond migration mechanism. Both product subclasses represent useful synthetic intermediates. As an initial demonstration, this sequence was used to prepare the side-chain of the natural product psymberin, as well as a ulosonic acid analogue.

FREE:Supporting Info. (3.2MB)PDF (1.3MB)

Published online: 8th September, 2022

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-22-14726
■ Novel Benzofuranoid Norlignans from the Aerial Parts of Asparagus cochinchinensis and Their Biological Activity

Baixiang Cai,* Jingyi Yue, Tao Xu, Jutao Wang , and Yang Yu*

*School of Pharmacy, Anhui University of Chinese Medicine, Yaohai District of Hefei City, Anhui Province, Mo Dian Xiang Anhui University of Chinese medicine shaoquan Lake Campus, 230012, China

Abstract

Three new benzofuranoid norlignans asparlignan A (1), B (2), and C (3) were isolated from the aerial parts of Asparagus cochinchinensis, in addition to previously known metabolites (4-6). The structures of these compounds were elucidated using a combination of spectroscopic analyses, including UV, IR, HRESIMS, 1D, and 2D NMR. Further, all compounds were evaluated for their anti-inflammatory activity and capability to inhibit nitric oxide (NO) production by RAW 264.7 macrophages and anticancer activity against three tumor cells.

FREE:Supporting Info. (2.6MB)PDF (464KB)

Published online: 6th September, 2022

Review | Regular issue | Prepress
DOI: 10.3987/REV-22-990
■ Mini Review on Pyrido[2,3-c]coumarins Backbone of Santiagonamine Antibiotics

Prasanta Patra* and Susanta Patra

*Chemisty, Jhargram Raj College, West Bengal, Jhargram College Rd, Jhargram, West Bengal, India

Abstract

Santiagonamine is a natural coumarin fused pyridine, specifically pyrido[2,3-c]coumarin derivative having wound-healing activities and is extracted from stems and branches of the South American shrub Berberis darwinii Hook. It was isolated by Shamma et al. in 1984. Both coumarin and pyridine represent an important class of a multi tasking and multi functional scaffolds in organic synthesis. So, the syntheses of coumarin fused pyridine derivatives have an immense impact in the field of organic and pharmaceutical chemistry due to various biological activities displayed by such classes of compounds as well as for their natural occurrences. The main purpose of this review is to focus on different synthetic methodologies for the synthesis of specifically pyrido[2,3-c]coumarins as it is the backbone of santiagonamine antibiotics. Several methods for the synthesis of pyrido[2,3-c]coumarins have been described in the literature, most of which use 3-aminocoumarin as the starting material.

FREE:PDF (877KB)

Published online: 6th September, 2022

Paper | Regular issue | Prepress
DOI: 10.3987/COM-22-14731
■ Reaction Pathway and Kinetic Study of 4,5-Dihydroxyimidazolidine-2-thione Synthesis by HPLC and NMR

Liudmila Kalichkina,* Dmitry Novikov, Oleg Kotelnikov, Viktor Malkov, and Alexey Knyazev

*Chemical department, Tomsk state university, 36 Lenin Ave., Tomsk, Russia, Russia

Abstract

Process of 4,5-dihydroxyimidazolidine-2-thione (DHIT) synthesis from thiourea and glyoxal is studied. Formation of imidazole-2-thiones and 4,5-dihydroxyimidazolidin-2-one as byproducts is confirmed by NMR. The kinetics of the scalable DHIT synthesis process is studied by HPLC, and the kinetic parameters of the model based on the proposed reaction scheme are calculated. The model correctly describes the kinetics of the DHIT formation and thiourea consumption.

FREE:PDF (1MB)

Published online: 31st August, 2022

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-22-14719
■ Antimicrobial Activities of Heliciopsis terminalis Trunk Extract

Charinrat Saechan, Uyen Hoang Nguyen, Zhichao Wang, Sachiko Sugimoto, Yoshi Yamano, Supinya Thanapongpichat, Katsuyoshi Matsunami, Hideaki Otsuka, Giang Minh Phan, Viet Hung Pham, Natakorn Nokchan, Jisnuson Svasti, Hansuk Buncherd,* and Jasadee Kaewsrichan*

*Faculty of Medical Technology, Prince of Songkla University, Songkhla 90110, Thailand

Abstract

Phenolic glucosides, methyl 5-(1,3-dihyroxyphenyl)pentanoate 1-O-β-D-glucopyranoside (1), ethyl 5-(1,3-dihyroxyphenyl)pentanoate 1-O-β-D-glucopyranoside (2), along with 2-(3-methoxy-4-hydroxyphenyl)propane-l,3-diol (3), C-veratroylglycol (4), 6'-[(E)-2''-hydroxymethyl-2''-butenoyl] arbutin (5), and (8'Z)-1,3-dihydroxy-5-[16'-(3'',5''-dihydroxyphenyl)-8'-hexadecen-1'-yl]benzene (6), were isolated from Heliciopsis terminalis. Their molecular structures were determined by extensive spectroscopic analyses. The antimicrobial activities of all compounds were evaluated. The results showed that only compound 6 expressed strong antimicrobial activity against Gram-positive bacteria.

FREE:Supporting Info. (1.6MB)PDF (801KB)

Published online: 22nd August, 2022

Review | Regular issue | Prepress
DOI: 10.3987/REV-22-988
■ The Azalogues of Pyrrolotetrazole – An Overview

Dietrich Moderhack*

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

Abstract

This overview is dealing with the seven azalogues of pyrrolotetrazole, i.e., the systems A–G, in all their manifold forms. Major interest is directed to the preparative chemistry, but theoretical work, in particular on the azolotetrazole–azidoazole isomerism ('ring–chain tautomerism'), will be looked at as well.

FREE:PDF (6.6MB)

Published online: 12th August, 2022

Review | Regular issue | Prepress
DOI: 10.3987/REV-22-986
■ Understanding the Diversity and Molecular Basis of Biosynthesis of Heterocyles in Natural Products Produced by Actinobacteria

Yohei Katsuyama*

*Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan

Abstract

Many of the natural products produced by actinomycetes have useful biological activities including antibiotic, antitumor and immunosuppressant activities, reflecting their structural diversity. In addition, many of them have heterocyclic rings in their structures, and these rings are considered to be important for their biological activities. Various chemical reactions and enzymes catalyzing them are used for their formation reactions. In this review, our recent examples of biosynthetic studies on the natural product with heterocycles in actinomycetes are summarized. These include indoline and tetrahydroquinoline ring formation using the nitrene-forming reaction found in the biosynthetic pathway of benzastatin, oxazoline ring formation in nonribosomal peptide synthetases and polyketide-derived piperidine alkaloid biosynthesis. These studies are expected to provide novel insights into enzyme chemistry as well as a new idea for synthetic organic chemists.

FREE:PDF (1.6MB)

Published online: 26th July, 2022

Review | Regular issue | Prepress
DOI: 10.3987/REV-22-985
■ Total Syntheses of Conhydrines via Ruthenium-Catalyzed Ring-Closing Metathesis (RCM) Reactions

Tian Jin,* Lu Zhao,* Hong-Ping Wang, Chichong Lu,* Zong-He Li, Zhe-Bin Zheng, and Won-Hun Ham*

*Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, Huaguan Road 168, Chengdu City, China

Abstract

Conhydrines are extremely interesting target molecules in organic synthesis because of their unique structural motifs and potent bioactivities. The ring-closing metathesis (RCM) reaction has received considerable attention for a long time. In this review, we highlight 13 total syntheses of conhydrines by using RCM reaction as the key step from different research groups during the period 2000 to 2021.

FREE:PDF (1.7MB)
15 data found. 1 - 15 listed