Current Regular Issue

Vol. 104, No. 9, 2022

12 data found. 1 - 12 listed
Contents | Regular issue | Vol 104, No. 9, 2022
Published online: 28th March, 2022
DOI: 10.3987/Contents-22-10409
Contents
FREE:PDF (2.7MB)
Review | Regular issue | Vol 104, No. 9, 2022, pp. 1535 - 1558
Published online: 24th June, 2022
DOI: 10.3987/REV-22-984
Gold-Catalyzed Skeletal Rearrangement Reactions of O-Propargylic and O-Homopropargylic Oximes

Itaru Nakamura* and Masahiro Terada

*Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan

Abstract

Au-catalyzed skeletal rearrangement reactions of O-propargylic oximes, which were derived from the condensation of N-propargyloxyamine with either formaldehyde or glyoxylate, afforded the corresponding 4-methylenated isoxazolines via C=N bond cleavage. The obtained isoxazolines underwent carbonyl–ene reactions, generating functionalized isoxazoles in good yields. Moreover, a sequence of Au-catalyzed reactions followed by a carbonyl–ene reaction of enantioenriched substrate produced isoxazoles having a chiral side chain, with excellent levels of chirality transfer. In contrast, the Au-catalyzed reactions of O-propargylic oximes bearing an electron-deficient aryl group on the oxime carbon proceeded via N–O bond cleavage, affording oxazines in good yields.

PDF (2MB)PDF with Links (1.9MB)
Communication | Regular issue | Vol 104, No. 9, 2022, pp. 1559 - 1564
Published online: 13th July, 2022
DOI: 10.3987/COM-22-14698
Facile and Efficient N-Boc Deprotection of Amide and Sulfonamide under Microwave Irradiation in Water

Zhi-you Huang,* Wen-sheng Li, Jia Xu, Bing-rong Xiang, Min-xin Li, Li-jun Chen, and Ye-she Wang

*College of Urban and Rural Construction, Shaoyang University, Shaoyang, 422000, P.R.China

Abstract

A facile and efficient microwave-assisted N-Boc deprotection of amide and sulfonamide in water was developed. With environmentally friendly, operational-simplicity, good substrate scope and excellent product yields, this methodology is superior to the existing approach. Significantly, the target compound was obtained after filtration and dry.

Supporting Info. (5.4MB)PDF (724KB)PDF with Links (723KB)
Communication | Regular issue | Vol 104, No. 9, 2022, pp. 1565 - 1572
Published online: 26th July, 2022
DOI: 10.3987/COM-22-14714
Direct β-Alkenylation of Thiophenes with Alkenyl Halides Catalyzed by a Dinuclear Palladium Complex

Nozomi Asahara and Naofumi Tsukada*

*Department of Chemistry, Faculty of Science, Shizuoka University, 836 Ohya, Shizuoka 422-8529, Japan

Abstract

Direct alkenylation of thiophenes with iodoalkenes proceeded in the presence of a dinuclear palladium complex formed by a chelate-bridging ligand. In most reactions, β-alkenylthiophenes were obtained with good to high regioselectivity.

PDF (802KB)PDF with Links (803KB)
Paper | Regular issue | Vol 104, No. 9, 2022, pp. 1573 - 1583
Published online: 28th June, 2022
DOI: 10.3987/COM-22-14685
Regioselective Synthesis of Some Novel Phosphonopyrazole, Phosphonopyrimidine and Phosphonodiazepine Compounds Containing Coumarin Ring

Tarik E. Ali* and Mohammed A. Assiri

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

Abstract

A convenient regioselective synthesis of some novel phosphonopyrazole, phosphonopyrimidine and phosphonodiazepine derivatives containing a coumarin ring, was designed. The methodology involves one-pot reaction of 3-(2-bromoacetyl)-2H-chromen-2-one (1) with dimethylformamide dimethyl acetal and diethyl phosphite to give diethyl [2-bromo-3-oxo-3-(2-oxo-2H-chromen-3-yl)prop-1-en-1-yl]phosphonate (2). The successful heterocyclization of substrate 2 with 1,2-, 1,3- and 1,4-diamine reagents afforded the target products in moderate to good yields.

PDF (739KB)PDF with Links (765KB)
Paper | Regular issue | Vol 104, No. 9, 2022, pp. 1584 - 1600
Published online: 29th July, 2022
DOI: 10.3987/COM-22-14696
The Continuous-Flow Synthesis of 1H-Indazoles via Reaction of o-Fluorobenzaldehydes with tert-Butyl Carbazate under High Temperature

Wenjie Ye, Kai Zhu, Yiping Huang, Chuansong Duanmu, Yanxing Li, Jin Li, Weichuan Xu, and Feng Zhou*

*National & Local Joint Engineering Research Center for Deep Utilization Technology of Rock-salt Resource, Faculty of Chemical Engineering, Huaiyin Institute of Technology, Huai’an 223003, P. R. China

Abstract

Large amounts of 1H-indazoles have been developed and widely used in the production of diverse drugs. The reaction of 4-bromo-2,6-difluorobenzaldehyde with tert-butyl carbazate was selected as model transformation for the application of continuous-flow strategy to realize the efficient syntheses of 1H-indazoles in a highly controlled and safe manner. Various conditions (reaction temperature, residence time, solvent amount, the amount of tert-butyl carbazate, water content) were investigated under continuous-flow conditions to elucidate the benefits of using the continuous-flow strategy. The Box-Behnken design in response surface methodology was employed for the optimization of reaction conditions, and over 85% yield of 6-bromo-4-fluoro-1H-indazole could be achieved. Furthermore, the generality of the reaction conditions found optimal for the synthesis of 6-bromo-4-fluoro-1H-indazole was evaluated for the synthesis of several different 1H-indazoles.

PDF (1.3MB)PDF with Links (1.2MB)
Paper | Regular issue | Vol 104, No. 9, 2022, pp. 1601 - 1613
Published online: 15th July, 2022
DOI: 10.3987/COM-22-14700
Reactivity of 4-Bromoacetyl-1,2,3-triazoles towards Amines and Phenols: Synthesis and Antimicrobial Activity of Novel Heterocycles

Bakr F. Abdel-Wahab, Hanan A. Mohamed, Abdelbasset A. Farahat, Benson M. Kariuki, and Gamal A. El-Hiti*

*Department of Optometry, College of Applied Medical Sciences, King Saud University, P.O. Box 10219, Riyadh 11433, Saudi Arabia

Abstract

The reactivity of 4-bromoacetyl-1H-1,2,3-triazoles towards amines and phenols was studied. Reaction of 4-bromoacetyl-1H-1,2,3-triazole (1a; R = H) with benzylamine (2) in the absence of any catalyst unexpectedly afforded heterocycle 2,5-bis(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)pyrazine (4) in 50% yield. Additionally, the reaction of 1b (R = Br) with 4-bromoaniline and of 1c (R = Me) or 1d (R = NO2) with 1H-benzotriazole in basic media gave the expected aminoketone products 8 and 9a or 9b in high yields. Furthermore, the reaction of 1c (R = Me) or 1e (R = Cl) with phenol or β-naphthol in basic media led to the production of keto-ethers 10 or 11, respectively in an excellent yield. Compound 10 showed the highest inhibitory effect against the growth of the tested pathogens.

PDF (1.5MB)PDF with Links (1.3MB)
Paper | Regular issue | Vol 104, No. 9, 2022, pp. 1614 - 1623
Published online: 15th July, 2022
DOI: 10.3987/COM-22-14703
Synthesis of 2,3-Anthracenedicarboxylic-Acid-Derived Fluorophore and Chemiluminophore Incorporating Dipicolylaminomethyl Receptors, and Their Luminescence Responses to Metal Ions

Naomi Yamazaki, Ayako Matsui, Kyosuke Satake, and Hideki Okamoto*

*Department of Chemistry, Faculty of Science, Okayama University, 3-1-1 Tsushima-naka, Okayama 700-8530, Japan

Abstract

2,3-Anthracenedicarboxylic-acid-derived carboximide 1 and cyclic-hydrazide 2, incorporating dipicolylaminomethyl receptors, have been respectively prepared as novel fluorescence and chemiluminescence probes for metal cations. Carboximide 1 was essentially non-fluorescent in acetonitrile whereas it produced intense fluorescence (λFLmax 470 nm) upon addition of Zn2+ (off–on response). Cyclic-hydrazide 2 gave off blue chemiluminescence emission (λCLmax 465 nm) after addition of alkaline H2O2 and iodide ion in dimethyl sulfoxide. Addition of metal cations, e.g. Zn2+, into the chemiluminescence system resulted in significant quenching of the chemiluminescence (on–off response). Therefore, the effects of the metal cation on the chemiluminescence behavior of cyclic-hydrazide 2 showed clear contrast to those on the fluorescence behavior of carboximide 1.

Supporting Info. (324KB)PDF (1.3MB)PDF with Links (1.2MB)
Short Paper | Regular issue | Vol 104, No. 9, 2022, pp. 1625 - 1640
Published online: 30th June, 2022
DOI: 10.3987/COM-22-14686
Efficient and Aqueous Synthesis of 3,4-Disubstituted Isoxazol-5(4H)-one Derivatives Using Piperazine under Green Conditions

Ziba Daroughezadeh and Hamzeh Kiyani*

*School of Chemistry, Damghan University, 36719-41167 Damghan, Iran

Abstract

The one-pot, three-component, as well as expeditious synthesis of 3,4-disubstitted isoxazol-5(4H)-ones has been attained from the heterocyclization of various aryl/heteroaryl aldehydes, active methylene compounds, and hydroxylamine hydrochloride in the presence of piperazine as the efficient, low-cost, commercially available, and eco-friendliness basic organocatalyst. This double secondary amine catalyst was found that catalyzed the synthesis of isoxazol-5(4H)-ones under green conditions. The additional features of the present catalyst include readily available starting materials, relatively low catalyst loading, using water as a green solvent, broad substrate scope, simplicity, good to excellent reaction yields, faster synthesis, and avoiding the hazardous organic solvents.

PDF (1MB)PDF with Links (938KB)
Short Paper | Regular issue | Vol 104, No. 9, 2022, pp. 1641 - 1648
Published online: 22nd July, 2022
DOI: 10.3987/COM-22-14697
An Efficient Method for the Synthesis of N-Aryl Substituted C1-Functionalized 1,2,3,4-Tetrahydroisoquinolines

Hairong Luo,* Fen Tian, Yi He, Xurong Liu, Jing Li, and Meihang Chen*

*College of Material and Chemical Engineering, Tongren University, Tongren,Guizhou 554300, China

Abstract

An efficient and facile cyclic iminium-ion-based strategy has been developed for the synthesis of structurally diverse N-aryl substituted C1-functionalized THIQs. Cyclic iminium ions generated in situ from 2-(2-bromomethyl)benzaldehyde reacted with acetone to furnish ketone moiety at C-1 position in THIQs in moderate to good yields.

Supporting Info. (1.2MB)PDF (742KB)PDF with Links (746KB)
Short Paper | Regular issue | Vol 104, No. 9, 2022, pp. 1649 - 1660
Published online: 15th July, 2022
DOI: 10.3987/COM-22-14699
Molecular Iodine Mediated Synthesis of 2,4,5-Trisubstituted Imidazoles Commencing from α-Methylene Ketones and Benzylic Primary Alcohols Using a One-Pot, Two-Step Approach

Lindokuhle P. Mabizela and Vineet Jeena*

*School of Chemistry and Physics, University of KwaZulu-Natal, Scottsville, Pietermaritzburg, 3209, South Africa

Abstract

A simple one-pot, two-step approach to 2,4,5-trisubstituted imidazoles has been developed commencing from α-methylene ketones and primary alcohols. Using an environmentally friendly, inexpensive, and readily available iodine-based system, a series of trisubstituted imidazoles were prepared in moderate to good yields under mild reaction conditions.

Supporting Info. (1.5MB)PDF (805KB)PDF with Links (812KB)
Short Paper | Regular issue | Vol 104, No. 9, 2022, pp. 1661 - 1667
Published online: 20th July, 2022
DOI: 10.3987/COM-22-14713
New Anti-TMV Isochromenes from Nicotiana tabacum-Derived Endophytic Fungus Aspergillus versicolor

Qiu-Fen Hu, Ling-Fang Zhang, Guang-Hai Zhang, Mei-Fen Bao, Yin-Ke Li, Dong Miao, Yu-Ping Wu, Gang Du,* and Guang-Hui Kong*

*Key Laboratory of Chemistry in Ethnic Medicinal Resources, Yunnan Minzu University, Kunming 60500, P. R. China

Abstract

Three new isochromenes, versicolols G-I (1-3), together with four known analogues (4-7) were isolated from the fermentation products of a Nicotiana tabacum-derived endophytic fungus Aspergillus versicolor. Their structures were elucidated by spectroscopic methods, including extensive 1H, 13C, and 2D-NMR techniques. Compounds 1-3 were also tested for their anti-tobacco mosaic virus (anti-TMV) activities, and the results revealed that compound 1 exhibited high anti-TMV activity with inhibition rate of 41.6%, and this rate are higher than that of positive control. Compounds 2 and 3 also showed potential anti-TMV activities with inhibition rates of 22.8 and 26.5%, respectively.

Supporting Info. (523KB)PDF (755KB)PDF with Links (741KB)
12 data found. 1 - 12 listed