scholarly journals Modular and stereoselective synthesis of tetrasubstituted vinyl sulfides leading to a library of AIEgens

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xun-Shen Liu ◽  
Zhiqiong Tang ◽  
Zhiming Li ◽  
Mingjia Li ◽  
Lin Xu ◽  
...  
Keyword(s):  
Sulfur Atom ◽  
Density Functional ◽  
Stereoselective Synthesis ◽  
Photophysical Properties ◽  
Density Functional Theory Calculation ◽  
Vital Role ◽  
Biologically Active ◽  
Vinyl Sulfides ◽  
Emission Effect ◽  
Diazo Carbonyl Compounds

AbstractTetraarylethylenes exhibit intriguing photophysical properties and sulfur atom frequently play a vital role in organic photoelectric materials and biologically active compounds. Tetrasubstituted vinyl sulfides, which include both sulfur atom and tetrasubstituted alkenes motifs, might be a suitable skeleton for the discovery of the new material molecules and drug with unique functions and properties. However, how to modular synthesis these kinds of compounds is still challenging. Herein, a chemo- and stereo-selective Rh(II)-catalyzed [1,4]-acyl rearrangements of α-diazo carbonyl compounds and thioesters has been developed, providing a modular strategy to a library of 63 tetrasubstituted vinyl sulfides. In this transformation, the yield is up to 95% and the turnover number is up to 3650. The mechanism of this reaction is investigated by combining experiments and density functional theory calculation. Moreover, the “aggregation-induced emission” effect of tetrasubstituted vinyl sulfides were also investigated, which might useful in functional material, biological imaging and chemicalnsing via structural modification.

scholarly journals Expedient synthesis of E-hydrazone esters and 1H-indazole scaffolds through heterogeneous single-atom platinum catalysis

2019 ◽  
Vol 5 (12) ◽  
pp. eaay1537 ◽  
Author(s):  
Cuibo Liu ◽  
Zhongxin Chen ◽  
Huan Yan ◽  
Shibo Xi ◽  
Kah Meng Yam ◽  
...  
Keyword(s):  
Density Functional ◽  
Stereoselective Synthesis ◽  
Density Functional Theory Calculations ◽  
Building Blocks ◽  
Hydrogenation Reaction ◽  
Biologically Active ◽  
Single Atom ◽  
One Pot ◽  
Platinum Catalysis ◽  
Scalable Synthesis

Unprotected E-hydrazone esters are prized building blocks for the preparation of 1H-indazoles and countless other N-containing biologically active molecules. Despite previous advances, efficient and stereoselective synthesis of these compounds remains nontrivial. Here, we show that Pt single atoms anchored on defect-rich CeO2 nanorods (Pt1/CeO2), in conjunction with the alcoholysis of ammonia borane, promotes exceptionally E-selective hydrogenation of α-diazoesters to afford a wide assortment of N-H hydrazone esters with an overall turnover frequency of up to 566 hours−1 upon reaction completion. The α-diazoester substrates could be generated in situ from readily available carboxylic esters in one-pot hydrogenation reaction. Utility is demonstrated through concise, scalable synthesis of 1H-indazole–derived pharmaceuticals and their 15N-labeled analogs. The present protocol highlights a key mechanistic nuance wherein simultaneous coordination of a Pt site with the diazo N═N and ester carbonyl motifs plays a central role in controlling stereoselectivity, which is supported by density functional theory calculations.

scholarly journals Microwave-Assisted Synthesis, Optical and Theoretical Characterization of Novel 2-(imidazo[1,5-a]pyridine-1-yl)pyridinium Salts

Chemistry ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 714-727
Author(s):  
Luca M. Cavinato ◽  
Giorgio Volpi ◽  
Elisa Fresta ◽  
Claudio Garino ◽  
Andrea Fin ◽  
...  
Keyword(s):  
Density Functional ◽  
Chemical Structure ◽  
Photophysical Properties ◽  
Density Functional Theory Calculation ◽  
Microwave Assisted Synthesis ◽  
Pyridinium Salts ◽  
Chemical Structures ◽  
Theory Calculation

In the last few years, imidazo[1,5-a]pyridine scaffolds and derivatives have attracted growing attention due to their unique chemical structure and optical behaviors. In this work, a series of pyridylimidazo[1,5-a]pyridine derivatives and their corresponding pyridinium salts were synthesized and their optical properties investigated to evaluate the effect of the quaternization on the optical features both in solution and polymeric matrix. A critical analysis based on the spectroscopic data, chemical structures along with density functional theory calculation is reported to address the best strategies to prevent aggregation and optimize the photophysical properties. The obtained results describe the relationship between chemical structure and optical behaviors, highlighting the role of pendant pyridine. Finally, the presence of a positive charge is fundamental to avoid any possible aggregation process in polymeric films.

Ordered boron phosphorus codoped graphene realizing widely tunable quasi Dirac-cone gap

2021 ◽  
Vol 9 (12) ◽  
pp. 4316-4321
Author(s):  
L.-B. Meng ◽  
S. Ni ◽  
Z. M. Zhang ◽  
S. K. He ◽  
W. M. Zhou
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculation ◽  
Dirac Cone ◽  
Functional Theory ◽  
Theory Calculation

Density functional theory calculation predicts a novel ordered boron phosphorus codoped graphene realizing a widely tunable Dirac-cone gap.

scholarly journals Uncovering Prospective Role and Applications of Existing and New Nutraceuticals from Bacterial, Fungal, Algal and Cyanobacterial, and Plant Sources

2021 ◽  
Vol 13 (7) ◽  
pp. 3671
Author(s):  
Jameel R. Al-Obaidi ◽  
Khalid H. Alobaidi ◽  
Bilal Salim Al-Taie ◽  
David Hong-Sheng Wee ◽  
Hasnain Hussain ◽  
...  
Keyword(s):  
Human Health ◽  
Well Being ◽  
Vital Role ◽  
Biologically Active ◽  
Future Perspective ◽  
The Public ◽  
Biological Sources ◽  
Pharmaceutical Properties ◽  
Plant Sources ◽  
Health And Well Being

Nutraceuticals are a category of products more often associated with food but having pharmaceuticals property and characteristics. However, there is still no internationally accepted concept of these food-pharmaceutical properties, and their interpretation can differ from country to country. Nutraceuticals are used as part of dietary supplements in most countries. They can be phytochemicals which are biologically active and have health benefits. These can be supplied as a supplement and/or as a functional food to the customer. For human health and longevity, these materials are likely to play a vital role. Consumption of these items is typical without a therapeutic prescription and/or supervision by the vast majority of the public. The development of nutraceuticals can be achieved through many bioresources and organisms. This review article will discuss the current research on nutraceuticals from different biological sources and their potential use as an agent for improving human health and well-being, as well as the gaps and future perspective of research related to nutraceutical development.

Photophysical Properties of N-Methyl and N-Acetyl Substituted Alloxazine: A Theoretical Investigation

2021 ◽  
Author(s):  
Huimin Guo ◽  
Xiaolin Ma ◽  
Zhiwen Lei ◽  
Yang Qiu ◽  
Bernhard Dick ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Theoretical Investigation ◽  
Density Functional ◽  
Photophysical Properties ◽  
Time Dependent ◽  
Functional Theory ◽  
Td Dft ◽  
Dependent Density

The electronic structure and photophysical properties of a series of N-Methyl and N-Acetyl substituted alloxazine (AZs) were investigated with extensive density functional theory (DFT) and time-dependent density functional theory (TD-DFT)...

scholarly journals Regulating coordination number in atomically dispersed Pt species on defect-rich graphene for n-butane dehydrogenation reaction

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaowen Chen ◽  
Mi Peng ◽  
Xiangbin Cai ◽  
Yunlei Chen ◽  
Zhimin Jia ◽  
...  
Keyword(s):  
Coordination Number ◽  
Density Functional ◽  
Activation Barrier ◽  
Density Functional Theory Calculation ◽  
Catalytic Performance ◽  
Atomic Level ◽  
Metal Nanoparticle ◽  
Single Atom ◽  
Nano Structure ◽  
Theory Calculation

AbstractMetal nanoparticle (NP), cluster and isolated metal atom (or single atom, SA) exhibit different catalytic performance in heterogeneous catalysis originating from their distinct nanostructures. To maximize atom efficiency and boost activity for catalysis, the construction of structure–performance relationship provides an effective way at the atomic level. Here, we successfully fabricate fully exposed Pt3 clusters on the defective nanodiamond@graphene (ND@G) by the assistance of atomically dispersed Sn promoters, and correlated the n-butane direct dehydrogenation (DDH) activity with the average coordination number (CN) of Pt-Pt bond in Pt NP, Pt3 cluster and Pt SA for fundamentally understanding structure (especially the sub-nano structure) effects on n-butane DDH reaction at the atomic level. The as-prepared fully exposed Pt3 cluster catalyst shows higher conversion (35.4%) and remarkable alkene selectivity (99.0%) for n-butane direct DDH reaction at 450 °C, compared to typical Pt NP and Pt SA catalysts supported on ND@G. Density functional theory calculation (DFT) reveal that the fully exposed Pt3 clusters possess favorable dehydrogenation activation barrier of n-butane and reasonable desorption barrier of butene in the DDH reaction.

Sign in / Sign up

Export Citation Format

Share Document