A Facile Modular Addition Approach to Size Control in the Synthesis of Oxo Bridged Phosphazane Macrocycles

Author(s):  
Xiaoyan Shi ◽  
felix leon ◽  
Rakesh Ganguly ◽  
jesus diaz ◽  
Felipe Garcia

Inorganic macrocycles remain largely underdeveloped compared with their organic counterparts due to the challenges involved in their synthesis. Among them, cyclodiphosphazane macrocycles have shown to be promising candidates for supramolecular chemistry applications. However, further developments have been handicapped by the lack of synthetic routes to high-order cyclodiphosphazane macrocycles. Here we report the synthesis of high-order oxygen-bridged phosphazane macrocycles via a “3+n” (n= 1 and 3) condensation reaction synthetic strategy using novel trimeric building blocks. Using this method, the first-ever all-PIII high-order hexameric cyclodiphosphazane macrocycle was isolated, displaying a larger macrocyclic cavity than comparable organic crown-ether counterparts. Our approach demonstrates that increasing building block complexity enables unprecedented rational control over macrocycle size.

2020 ◽  
Author(s):  
Xiaoyan Shi ◽  
felix leon ◽  
Rakesh Ganguly ◽  
jesus diaz ◽  
Felipe Garcia

Inorganic macrocycles remain largely underdeveloped compared with their organic counterparts due to the challenges involved in their synthesis. Among them, cyclodiphosphazane macrocycles have shown to be promising candidates for supramolecular chemistry applications. However, further developments have been handicapped by the lack of synthetic routes to high-order cyclodiphosphazane macrocycles. Here we report the synthesis of high-order oxygen-bridged phosphazane macrocycles via a “3+n” (n= 1 and 3) condensation reaction synthetic strategy using novel trimeric building blocks. Using this method, the first-ever all-PIII high-order hexameric cyclodiphosphazane macrocycle was isolated, displaying a larger macrocyclic cavity than comparable organic crown-ether counterparts. Our approach demonstrates that increasing building block complexity enables unprecedented rational control over macrocycle size.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Xiaoyan Shi ◽  
Felix León ◽  
How Chee Ong ◽  
Rakesh Ganguly ◽  
Jesús Díaz ◽  
...  

AbstractInorganic macrocycles remain largely underdeveloped compared with their organic counterparts due to the challenges involved in their synthesis. Among them, cyclodiphosphazane macrocycles have shown to be promising candidates for supramolecular chemistry applications due to their ability to encapsulate small molecules or ions within their cavities. However, further developments have been handicapped by the lack of synthetic routes to high-order cyclodiphosphazane macrocycles. Moreover, current approaches allow little control over the size of the macrocycles formed. Here we report the synthesis of high-order oxygen-bridged phosphazane macrocycles via a “3 + n cyclisation” (n = 1 and 3). Using this method, an all-PIII high-order hexameric cyclodiphosphazane macrocycle was isolated, displaying a larger macrocyclic cavity than comparable organic crown-ethers. Our approach demonstrates that increasing building block complexity enables precise control over macrocycle size, which will not only generate future developments in both the phosphazane and main group chemistry but also in the fields of supramolecular chemistry.


2020 ◽  
Vol 24 (21) ◽  
pp. 2475-2497
Author(s):  
Andrea Verónica Rodríguez-Mayor ◽  
German Jesid Peralta-Camacho ◽  
Karen Johanna Cárdenas-Martínez ◽  
Javier Eduardo García-Castañeda

Glycoproteins and glycopeptides are an interesting focus of research, because of their potential use as therapeutic agents, since they are related to carbohydrate-carbohydrate, carbohydrate-protein, and carbohydrate-lipid interactions, which are commonly involved in biological processes. It has been established that natural glycoconjugates could be an important source of templates for the design and development of molecules with therapeutic applications. However, isolating large quantities of glycoconjugates from biological sources with the required purity is extremely complex, because these molecules are found in heterogeneous environments and in very low concentrations. As an alternative to solving this problem, the chemical synthesis of glycoconjugates has been developed. In this context, several methods for the synthesis of glycopeptides in solution and/or solid-phase have been reported. In most of these methods, glycosylated amino acid derivatives are used as building blocks for both solution and solid-phase synthesis. The synthetic viability of glycoconjugates is a critical parameter for allowing their use as drugs to mitigate the impact of microbial resistance and/or cancer. However, the chemical synthesis of glycoconjugates is a challenge, because these molecules possess multiple reaction sites and have a very specific stereochemistry. Therefore, it is necessary to design and implement synthetic routes, which may involve various protection schemes but can be stereoselective, environmentally friendly, and high-yielding. This review focuses on glycopeptide synthesis by recapitulating the progress made over the last 15 years.


2020 ◽  
Vol 09 ◽  
Author(s):  
Minita Ojha ◽  
R. K. Bansal

Background: During the last two decades, horizon of research in the field of Nitrogen Heterocyclic Carbenes (NHC) has widened remarkably. NHCs have emerged as ubiquitous species having applications in a broad range of fields, including organocatalysis and organometallic chemistry. The NHC-induced non-asymmetric catalysis has turned out to be a really fruitful area of research in recent years. Methods: By manipulating structural features and selecting appropriate substituent groups, it has been possible to control the kinetic and thermodynamic stability of a wide range of NHCs, which can be tolerant to a variety of functional groups and can be used under mild conditions. NHCs are produced by different methods, such as deprotonation of Nalkylhetrocyclic salt, transmetallation, decarboxylation and electrochemical reduction. Results: The NHCs have been used successfully as catalysts for a wide range of reactions making a large number of building blocks and other useful compounds accessible. Some of these reactions are: benzoin condensation, Stetter reaction, Michael reaction, esterification, activation of esters, activation of isocyanides, polymerization, different cycloaddition reactions, isomerization, etc. The present review includes all these examples published during the last 10 years, i.e. from 2010 till date. Conclusion: The NHCs have emerged as versatile and powerful organocatalysts in synthetic organic chemistry. They provide the synthetic strategy which does not burden the environment with metal pollutants and thus fit in the Green Chemistry.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1214
Author(s):  
Sergey N. Podyachev ◽  
Rustem R. Zairov ◽  
Asiya R. Mustafina

The present review is aimed at highlighting outlooks for cyclophanic 1,3-diketones as a new type of versatile ligands and building blocks of the nanomaterial for sensing and bioimaging. Thus, the main synthetic routes for achieving the structural diversity of cyclophanic 1,3-diketones are discussed. The structural diversity is demonstrated by variation of both cyclophanic backbones (calix[4]arene, calix[4]resorcinarene and thiacalix[4]arene) and embedding of different substituents onto lower or upper macrocyclic rims. The structural features of the cyclophanic 1,3-diketones are correlated with their ability to form lanthanide complexes exhibiting both lanthanide-centered luminescence and magnetic relaxivity parameters convenient for contrast effect in magnetic resonance imaging (MRI). The revealed structure–property relationships and the applicability of facile one-pot transformation of the complexes to hydrophilic nanoparticles demonstrates the advantages of 1,3-diketone calix[4]arene ligands and their complexes in developing of nanomaterials for sensing and bioimaging.


2010 ◽  
Vol 49 (13) ◽  
pp. 5971-5976 ◽  
Author(s):  
Hu Zhou ◽  
Ai-Hua Yuan ◽  
Su-Yan Qian ◽  
You Song ◽  
Guo-Wang Diao

2020 ◽  
Author(s):  
Venkatesan Thimmakondu ◽  
Krishnan Thirumoorthy

Novel flat crown ether molecules have been characterized in silico using DFT hybrid and hybrid-meta functionals. Monomer units of Si2C3 with a planar tetracoordinate carbon atom have been used as building blocks. Alkali (Li+, Na+, K+, Rb+, and Cs+) and alkaline-earth (Ca2+, Sr2+, and Ba2+) metals, and uranyl (UO2+ 2 ) ion selective complexes have also been theoretically identified. The high symmetry and higher structural rigidity of the host molecules may likely to impart higher selectivity in chelation. Theoretical binding energies have been computed and experimental studies are invited.


Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1063
Author(s):  
Katarzyna Mituła ◽  
Michał Dutkiewicz ◽  
Julia Duszczak ◽  
Monika Rzonsowska ◽  
Beata Dudziec

The scientific reports on polyhedral oligomeric silsesquioxanes are mostly focused on the formation of completely condensed T8 cubic type structures and recently so-called double-decker derivatives. Herein, we report on efficient synthetic routes leading to trifunctionalized, open-cage silsesquioxanes with alkenyl groups of varying chain lengths from -vinyl to -dec-9-enyl and two types of inert groups (iBu, Ph) at the silsesquioxane core. The presented methodology was focused on hydrolytic condensation reaction and it enabled obtaining titled compounds with high yields and purity. A parallel synthetic methodology that was based on the hydrosilylation reaction was also studied. Additionally, a thorough characterization of the obtained compounds was performed, also in terms of their thermal stability, melting and crystallization temperatures (TGA and DSC) in order to show the changes in the abovementioned parameters dependent on the type of reactive as well as inert groups at Si-O-Si core. The presence of unsaturated alkenyl groups has a profound impact on the application potential of these systems, i.e., as modifiers or comonomers for copolymerization reaction.


2018 ◽  
Vol 6 (21) ◽  
pp. 5662-5670 ◽  
Author(s):  
Bogyu Lim ◽  
Dang Xuan Long ◽  
Song-Yi Han ◽  
Yoon-Chae Nah ◽  
Yong-Young Noh

We report an effective synthetic strategy to achieve well-defined regioregular alternative conjugated polymers using large molecular weight regioregular monomers.


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