Organoselenium and organotellurium compounds containing chalcogen-oxygen bonds in organic synthesis or related processes

2018 ◽  
Vol 4 (5) ◽  
Author(s):  
Alexandra Pop ◽  
Cristian Silvestru ◽  
Anca Silvestru
Keyword(s):  
Organic Synthesis ◽  
Oxidation State ◽  
Reaction Rate ◽  
Green Solvents ◽  
Organic Transformations ◽  
Cyclization Reactions ◽  
Chiral Species ◽  
Organotellurium Compounds ◽  
New Strategies

Abstract This chapter emphasizes aspects related to the role of organochalcogen (Se, Te) compounds with single E‒O and/or double E=O (E=Se, Te) bonds in organic synthesis, as reagents, intermediates, or catalysts, and it gives a larger extent mainly to data reported in the field during the last ten years. For each of these two heavier chalcogens the material is structured according to the oxidation state of the chalcogen and, for the same oxidation state, in sections dedicated to a particular type of compounds. Functionalization or cyclization reactions in which the organochalcogen compounds take part as nucleophiles, electrophiles or radicals, employed in various synthetic transformations, are discussed and, where available, the mechanistic aspects are outlined. New chiral species and new strategies were developed during last years in order to increase the yield, the reaction rate and the stereoselectivity in specific organic transformations, i.e. addition, oxidation, elimination, cyclization or rearrangement reactions. A notably attention was devoted to easily accessible and environmental friendly catalysts, re-usable and “green” solvents, as well as waste-free procedures.

The double and triple role of L-(+)-tartaric acid and dimethyl urea: A prevailing green approach in organic synthesis

2021 ◽  
Vol 25 ◽  
Author(s):  
Rashid Ali ◽  
Ajay Kumar Chinnam ◽  
Vikas R. Aswar
Keyword(s):  
Tartaric Acid ◽  
Organic Synthesis ◽  
Low Cost ◽  
Organic Transformations ◽  
Green Approach ◽  
Dimethyl Urea ◽  
Low Toxicity ◽  
The One ◽  
Near Future

: The deep eutectic mixtures (DESs), introduced as novel alternative to usual volatile organic solvents for organic transformations has attracted a tremendous attention of the research community because of their low cost, negligible vapour pressure, low toxicity, biodegradability, recyclability, insensitive towards moisture, and readily availability from bulk renewable resources. Although, the low melting mixture of dimethyl urea (DMU)/L-(+)-tartaric acid (TA) is still infancy yet much effective as it play double and triple roles such as solvent, catalyst and/or reagent in a same pot for many crucial organic transformations. These unique properties of DMU/TA mixture prompted us to provide a quick overview of where the field stands presently, and where it might be going in near future. To our best knowledge, no review dealing with the applications of a low melting mixture of DMU/TA appeared in the literature except the one published in 2017 describing only the chemistry of indole systems. Therefore, we intended to reveal the developments of this versatile low melting mixture in the modern organic synthesis since its first report in 2011 by Köenig’s team to till date. Hopefully, the present review article will be useful to the researcher working not only in the arena of synthetic organic chemistry but also to the scientists working in other branches of science and technology.

scholarly journals Metal-Based Catalysts in Organic Synthesis

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1429
Author(s):  
Manas Sutradhar
Keyword(s):  
Organic Compounds ◽  
Organic Synthesis ◽  
Organic Transformations

The role of catalysts is extremely important for various organic transformations and the synthesis of organic compounds [...]

SELENIUM AS A VERSATILE REAGENT IN ORGANIC SYNTHESIS: MORE THAN ALLYLIC OXIDATION

2021 ◽  
Vol 18 ◽  
Author(s):  
Samuel Thurow ◽  
Laura Abenante ◽  
João Marcos Anghinoni ◽  
Eder João Lenardão
Keyword(s):  
Organic Synthesis ◽  
Selenium Dioxide ◽  
Allylic Oxidation ◽  
Organic Transformations ◽  
Naturally Occurring ◽  
Recent Advances ◽  
Versatile Reagent

: For many years since its discovery, Selenium has played the role of a bad boy who became a hero in organic transformations. Selenium dioxide, for instance, is one of the most remembered reagents in allylic oxidations, having been applied in the synthesis of several naturally occurring products. The main goal of this review is to show the recent advances in the use of classical and new selenium reagents in organic synthesis. As demonstrated through around 60 references discussed in this study, selenium can go even forward as a versatile reagent. We bring a collection of selenium reagents and their transformations that are still hidden from most synthetic organic chemists.

The Synthesis and Application of Functionalized Mesoporous Silica SBA-15 as Heterogeneous Catalyst in Organic Synthesis

2020 ◽  
Vol 24 ◽  
Author(s):  
Ghodsi Mohammadi Ziarani ◽  
Shima Roshankar ◽  
Fatemeh Mohajer ◽  
Alireza Badiei
Keyword(s):  
Mesoporous Silica ◽  
Heterogeneous Catalyst ◽  
Organic Synthesis ◽  
Lewis Acid ◽  
Heterogeneous Catalysts ◽  
Organic Transformations ◽  
Functionalized Mesoporous Silica ◽  
Silica Nanomaterials ◽  
Wide Range ◽  
Target Molecules

Abstract:: Mesoporous silica nanomaterials provide an extraordinary advantage for making new and superior heterogeneous catalysts because of their surface silanol groups. The functionalized mesoporous SBA-15, such as acidic, basic, BrÖnsted, lewis acid, and chiral catalysts, are used for a wide range of organic synthesis. The importance of the chiral ligands, which were immobilized on the SBA-15, was mentioned in this review to achieve chiral products as valuable target molecules. Herein, their synthesis and application in different organic transformations are reviewed from 2016 till date 2020.

Green Solvents in Organic Synthesis: An Overview II

2016 ◽  
Vol 20 (15) ◽  
pp. 1576-1583 ◽  
Author(s):  
Karem Shanab ◽  
Catharina Neudorfer ◽  
Helmut Spreitzer
Keyword(s):  
Organic Synthesis ◽  
Green Solvents

Recent Application of Polystyrene-supported Triphenylphosphine in Solid-Phase Organic Synthesis

2019 ◽  
Vol 23 (6) ◽  
pp. 643-678
Author(s):  
Lalthazuala Rokhum ◽  
Ghanashyam Bez
Keyword(s):  
Organic Synthesis ◽  
Combinatorial Chemistry ◽  
Solid Phase ◽  
Recent Application ◽  
Organic Transformations ◽  
Solid Phase Organic Synthesis ◽  
Wide Range ◽  
Fast Development ◽  
Polymer Supported

Recent years have witnessed a fast development of solid phase synthetic pathways, a variety of solid-supported reagent and its applications in diverse synthetic strategies and pharmaceutical applicability’s. Polymer-supported triphenylphosphine is getting a lot of applications owing to the speed and simplicity in the process. Furthermore, ease of recyclability and reuse of polymer-supported triphenylphosphine added its advantages. This review covers a wide range of useful organic transformations which are accomplished using cross-linked polystyrene-supported triphenylphosphine with the aim of giving renewed interest in the field of organic and medicinal-combinatorial chemistry.

Rhodamines as Photocatalyst in Organic Synthesis

2020 ◽  
Vol 07 ◽  
Author(s):  
Avik K. Bagdi ◽  
Papiya Sikdar
Keyword(s):  
Visible Light ◽  
Organic Synthesis ◽  
Organic Dyes ◽  
Transition Metal Catalysts ◽  
Visible Light Photocatalysis ◽  
Eosin Y ◽  
Organic Transformations ◽  
The Sustainable Development ◽  
Mechanistic Pathway ◽  
Green Model

Abstract:: Organic synthesis under environment friendly conditions has great impact in the sustainable development. In this context, visible light photocatalysis has emerged as a green model as this offers an energy-efficient pathway towards the organic transformation. Different transition-metal catalysts (Ir-, Ru-, Cu- etc) and organic dyes (eosin Y, rose bengal, methylene blue etc) are well-known photocatalysts in organic synthesis. Apart from the well-known organophotoredox catalysts, rhodamines (Rhodamine B and Rhodamine 6G) have been also employed as efficient photocatalysts for different organic transformations. In this review, we will focus on the photocatalysis by rhodamines in organic synthesis. Mechanistic pathway of the methodologies will also be discussed. We believe this review will stimulate the employment of rhodamines in the visible light photocatalysis for efficient organic transformations in the future.

scholarly journals The microbial world in a changing environment

2021 ◽  
Vol 94 (1) ◽  
Author(s):  
Rafael Vicuña ◽  
Bernardo González
Keyword(s):  
Climate Change ◽  
Microbial Communities ◽  
Recent Literature ◽  
Public Awareness ◽  
Complete Evaluation ◽  
Microbial World ◽  
Sustainable Environment ◽  
Entire Planet ◽  
New Strategies

Abstract Background In this article we would like to touch on the key role played by the microbiota in the maintenance of a sustainable environment in the entire planet. For obvious reasons, this article does not intend to review thoroughly this extremely complex topic, but rather to focus on the main threats that this natural scenario is presently facing. Methods Recent literature survey. Results Despite the relevance of microorganisms have in our planet, the effects of climate change on microbial communities have been scarcely and not systematically addressed in literature. Although the role of microorganisms in emissions of greenhouse gases has received some attention, there are several microbial processes that are affected by climate change with consequences that are presently under assessment. Among them, host-pathogen interactions, the microbiome of built environment, or relations among plants and beneficial microbes. Conclusions Further research is required to advance in knowledge of the effect of climate change on microbial communities. One of the main targets should be a complete evaluation of the global microbial functional diversity and the design of new strategies to cope with limitations in methods to grow microorganisms in the laboratory. These efforts should contribute to raise a general public awareness on the major role played by the microbiota on the various Earth ecosystems.

scholarly journals The activity status of cofilin is directly related to invasion, intravasation, and metastasis of mammary tumors

2006 ◽  
Vol 173 (3) ◽  
pp. 395-404 ◽  
Author(s):  
Weigang Wang ◽  
Ghassan Mouneimne ◽  
Mazen Sidani ◽  
Jeffrey Wyckoff ◽  
Xiaoming Chen ◽  
...  
Keyword(s):  
Cell Motility ◽  
Cell Invasion ◽  
Actin Polymerization ◽  
Cancer Cell Invasion ◽  
Invasion And Metastasis ◽  
Over Expression ◽  
Cell Biol ◽  
Tumor Cell Motility ◽  
New Strategies

Understanding the mechanisms controlling cancer cell invasion and metastasis constitutes a fundamental step in setting new strategies for diagnosis, prognosis, and therapy of metastatic cancers. LIM kinase1 (LIMK1) is a member of a novel class of serine–threonine protein kinases. Cofilin, a LIMK1 substrate, is essential for the regulation of actin polymerization and depolymerization during cell migration. Previous studies have made opposite conclusions as to the role of LIMK1 in tumor cell motility and metastasis, claiming either an increase or decrease in cell motility and metastasis as a result of LIMK1 over expression (Zebda, N., O. Bernard, M. Bailly, S. Welti, D.S. Lawrence, and J.S. Condeelis. 2000. J. Cell Biol. 151:1119–1128; Davila, M., A.R. Frost, W.E. Grizzle, and R. Chakrabarti. 2003. J. Biol. Chem. 278:36868–36875; Yoshioka, K., V. Foletta, O. Bernard, and K. Itoh. 2003. Proc. Natl. Acad. Sci. USA. 100:7247–7252; Nishita, M., C. Tomizawa, M. Yamamoto, Y. Horita, K. Ohashi, and K. Mizuno. 2005. J. Cell Biol. 171:349–359). We resolve this paradox by showing that the effects of LIMK1 expression on migration, intravasation, and metastasis of cancer cells can be most simply explained by its regulation of the output of the cofilin pathway. LIMK1-mediated decreases or increases in the activity of the cofilin pathway are shown to cause proportional decreases or increases in motility, intravasation, and metastasis of tumor cells.

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