Diorganyl Dichalcogenides, Copper and Iron Salts: Versatile Cyclization System to Achieve Carbo- and Heterocycles from Alkynes

Synthesis ◽  
2021 ◽  
Author(s):  
Carla Kornowski Jurunic ◽  
Andrei Lucca Belladona ◽  
Ricardo Frederico Schumacher ◽  
Benhur Godoi

Organochalcogen-containing cyclic molecules have shown several promising pharmacological properties. Consequently, different synthetic strategies have been developed to their obtaining in the last years. Particularly due to the low cost and environmental aspects, copper and iron-promoted cyclization reactions of alkynyl substrates have been broadly and efficiently applied to this purpose. In this way, this manuscript consists on an overview of the most recent advances in the synthesis of organochalcogen-containing carbo- and heterocycles by reacting diorganyl disulfides, diselenides and ditellurides with alkyne derivatives in the presence of copper and iron salts to promote cyclization reactions.

2020 ◽  
Vol 24 (24) ◽  
pp. 2823-2844
Author(s):  
Aditya Bhattacharyya

: Multiheteroatom-containing small-sized cyclic molecules such as 2- iminothiazolidines are often found to possess beneficial pharmacological properties. In this review article, the biological significance of 2-iminothiazolidines is discussed and the literature reports published in the last 15 years spanning from 2006 to 2020 describing various preparative routes to access 2-iminothiazolidine derivatives have been categorically and chronologically described. The notable synthetic methods discussed here involve ringexpansion transformations of nonactivated and activated aziridines, thiiranes, epoxides, and other miscellaneous reactions.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3694
Author(s):  
Luminita Georgeta Confederat ◽  
Cristina Gabriela Tuchilus ◽  
Maria Dragan ◽  
Mousa Sha’at ◽  
Oana Maria Dragostin

Despite the advantages presented by synthetic polymers such as strength and durability, the lack of biodegradability associated with the persistence in the environment for a long time turned the attention of researchers to natural polymers. Being biodegradable, biopolymers proved to be extremely beneficial to the environment. At present, they represent an important class of materials with applications in all economic sectors, but also in medicine. They find applications as absorbers, cosmetics, controlled drug delivery, tissue engineering, etc. Chitosan is one of the natural polymers which raised a strong interest for researchers due to some exceptional properties such as biodegradability, biocompatibility, nontoxicity, non-antigenicity, low-cost and numerous pharmacological properties as antimicrobial, antitumor, antioxidant, antidiabetic, immunoenhancing. In addition to this, the free amino and hydroxyl groups make it susceptible to a series of structural modulations, obtaining some derivatives with different biomedical applications. This review approaches the physico-chemical and pharmacological properties of chitosan and its derivatives, focusing on the antimicrobial potential including mechanism of action, factors that influence the antimicrobial activity and the activity against resistant strains, topics of great interest in the context of the concern raised by the available therapeutic options for infections, especially with resistant strains.


Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1804
Author(s):  
Guangmin Ren ◽  
Hongtao Han ◽  
Yixuan Wang ◽  
Sitong Liu ◽  
Jianyong Zhao ◽  
...  

Photocatalysis holds great promise as an efficient and sustainable oxidation technology for application in wastewater treatment. Rapid progress developing novel materials has propelled photocatalysis to the forefront of sustainable wastewater treatments. This review presents the latest progress on applications of photocatalytic wastewater treatment. Our focus is on strategies for improving performance. Challenges and outlooks in this promising field are also discussed. We hope this review will help researchers design low-cost and high-efficiency photocatalysts for water treatment.


2021 ◽  
Vol 11 (16) ◽  
pp. 7554
Author(s):  
Isiaka Alimi ◽  
Romil Patel ◽  
Nuno Silva ◽  
Chuanbowen Sun ◽  
Honglin Ji ◽  
...  

This paper reviews recent progress on different high-speed optical short- and medium-reach transmission systems. Furthermore, a comprehensive tutorial on high-performance, low-cost, and advanced optical transceiver (TRx) paradigms is presented. In this context, recent advances in high-performance digital signal processing algorithms and innovative optoelectronic components are extensively discussed. Moreover, based on the growing increase in the dynamic environment and the heterogeneous nature of different applications and services to be supported by the systems, we discuss the reconfigurable and sliceable TRxs that can be employed. The associated technical challenges of various system algorithms are reviewed, and we proffer viable solutions to address them.


ChemInform ◽  
2010 ◽  
Vol 33 (52) ◽  
pp. no-no
Author(s):  
Iwao Ojima ◽  
Andrew C. Moralee ◽  
Victor C. Vassar

Vibration ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 64-86 ◽  
Author(s):  
Amirtahà Taebi ◽  
Brian Solar ◽  
Andrew Bomar ◽  
Richard Sandler ◽  
Hansen Mansy

Cardiovascular disease is a major cause of death worldwide. New diagnostic tools are needed to provide early detection and intervention to reduce mortality and increase both the duration and quality of life for patients with heart disease. Seismocardiography (SCG) is a technique for noninvasive evaluation of cardiac activity. However, the complexity of SCG signals introduced challenges in SCG studies. Renewed interest in investigating the utility of SCG accelerated in recent years and benefited from new advances in low-cost lightweight sensors, and signal processing and machine learning methods. Recent studies demonstrated the potential clinical utility of SCG signals for the detection and monitoring of certain cardiovascular conditions. While some studies focused on investigating the genesis of SCG signals and their clinical applications, others focused on developing proper signal processing algorithms for noise reduction, and SCG signal feature extraction and classification. This paper reviews the recent advances in the field of SCG.


Author(s):  
Christopher M. Puchalsky

Bus rapid transit (BRT) is an evolving and promising transit mode that has emerged as a low-cost competitor to light rail transit (LRT) in providing medium-capacity semirapid transit. In addition, recent advances in diesel and compressed natural gas technology have caused the truism “electric rail is cleaner than diesel bus” to be revisited. A partial fuel cycle comparison of the regional or urban emissions of carbon monoxide, oxides of nitrogen, and volatile organic compounds from BRT and LRT is presented. The BRT analysis includes tailpipe exhaust emissions and fuel transportation, storage, and distribution emissions. The LRT analysis contains electric power plant emissions and line-loss-induced emissions. The analysis shows that whenever equal levels of technology are compared, LRT consistently performs better than BRT despite recent advances in the BRT mode. The analysis also shows that both modes are cleaner now than in the past.


2007 ◽  
Vol 17 (2) ◽  
pp. 1521-1524 ◽  
Author(s):  
M. W. Hooker ◽  
K. S. Kano ◽  
M. W. Stewart
Keyword(s):  
Low Cost ◽  

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