scholarly journals Three-component radical homo Mannich reaction

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shuai Shi ◽  
Wenting Qiu ◽  
Pannan Miao ◽  
Ruining Li ◽  
Xianfeng Lin ◽  
...  
Keyword(s):  
Mannich Reaction ◽  
Aliphatic Amine ◽  
Single Step ◽  
Great Utility ◽  
Powerful Approach ◽  
Desulfurization Process ◽  
Ionic Nature ◽  
The Mannich Reaction ◽  
Pharmaceutical Agents

AbstractAliphatic amine, especially tertiary aliphatic amine, is one of the most popular functionalities found in pharmaceutical agents. The Mannich reaction is a classical and widely used transformation for the synthesis of β-amino-carbonyl products. Due to an ionic nature of the mechanism, the Mannich reaction can only use non-enolizable aldehydes as substrates, which significantly limits the further applications of this powerful approach. Here we show, by employing a radical process, we are able to utilize enolizable aldehydes as substrates and develop the three-component radical homo Mannich reaction for the streamlined synthesis of γ-amino-carbonyl compounds. The electrophilic radicals are generated from thiols via the desulfurization process facilitated by visible-light, and then add to the electron-rich double bonds of the in-situ formed enamines to provide the products in a single step. The broad scope, mild conditions, high functional group tolerance, and modularity of this metal-free approach for the synthesis of complex tertiary amine scaffolds will likely be of great utility to chemists in both academia and industry.

In situ generation of less accessible Boc-imines from aldehydes: construction of a quaternary carbon by the Mannich reaction or unprecedented aldol reaction

2017 ◽  
Vol 15 (21) ◽  
pp. 4527-4530 ◽  
Author(s):  
Taichi Kano ◽  
Chihiro Homma ◽  
Keiji Maruoka
Keyword(s):  
Mannich Reaction ◽  
Aldol Reaction ◽  
Quaternary Carbon ◽  
Mannich Reactions ◽  
The Mannich Reaction ◽  
In Situ Generation

Mannich reactions of β-dicarbonyls with in situ generated less accessible Boc-imines from aldehydes were achieved.

scholarly journals Single Step In Situ Detection of Surface Protein and MicroRNA in Clustered Extracellular Vesicles Using Flow Cytometry

2021 ◽  
Vol 10 (2) ◽  
pp. 319
Author(s):  
Hee Cheol Yang ◽  
Won Jong Rhee
Keyword(s):  
Extracellular Vesicles ◽  
Liquid Biopsy ◽  
Molecular Beacon ◽  
Disease Diagnosis ◽  
Single Step ◽  
Flow Cytometer ◽  
Surface Proteins ◽  
Biomarker Detection ◽  
In Situ Detection

Because cancers are heterogeneous, it is evident that multiplexed detection is required to achieve disease diagnosis with high accuracy and specificity. Extracellular vesicles (EVs) have been a subject of great interest as sources of novel biomarkers for cancer liquid biopsy. However, EVs are nano-sized particles that are difficult to handle; thus, it is necessary to develop a method that enables efficient and straightforward EV biomarker detection. In the present study, we developed a method for single step in situ detection of EV surface proteins and inner miRNAs simultaneously using a flow cytometer. CD63 antibody and molecular beacon-21 were investigated for multiplexed biomarker detection in normal and cancer EVs. A phospholipid-polymer-phospholipid conjugate was introduced to induce clustering of the EVs analyzed using nanoparticle tracking analysis, which enhanced the detection signals. As a result, the method could detect and distinguish cancer cell-derived EVs using a flow cytometer. Thus, single step in situ detection of multiple EV biomarkers using a flow cytometer can be applied as a simple, labor- and time-saving, non-invasive liquid biopsy for the diagnosis of various diseases, including cancer.

scholarly journals Computational and experimental investigations of one-step conversion of poly(carbonate)s into value-added poly(aryl ether sulfone)s

2016 ◽  
Vol 113 (28) ◽  
pp. 7722-7726 ◽  
Author(s):  
Gavin O. Jones ◽  
Alexander Yuen ◽  
Rudy J. Wojtecki ◽  
James L. Hedrick ◽  
Jeannette M. García
Keyword(s):  
High Performance ◽  
Density Functional ◽  
Value Added ◽  
Single Step ◽  
Nucleophilic Attack ◽  
Experimental Investigations ◽  
Aryl Ether ◽  
One Step ◽  
Poly Carbonate

It is estimated that ∼2.7 million tons poly(carbonate)s (PCs) are produced annually worldwide. In 2008, retailers pulled products from store shelves after reports of bisphenol A (BPA) leaching from baby bottles, reusable drink bottles, and other retail products. Since PCs are not typically recycled, a need for the repurposing of the PC waste has arisen. We report the one-step synthesis of poly(aryl ether sulfone)s (PSUs) from the depolymerization of PCs and in situ polycondensation with bis(aryl fluorides) in the presence of carbonate salts. PSUs are high-performance engineering thermoplastics that are commonly used for reverse osmosis and water purification membranes, medical equipment, as well as high temperature applications. PSUs generated through this cascade approach were isolated in high purity and yield with the expected thermal properties and represent a procedure for direct conversion of one class of polymer to another in a single step. Computational investigations performed with density functional theory predict that the carbonate salt plays two important catalytic roles in this reaction: it decomposes the PCs by nucleophilic attack, and in the subsequent polyether formation process, it promotes the reaction of phenolate dimers formed in situ with the aryl fluorides present. We envision repurposing poly(BPA carbonate) for the production of value-added polymers.

scholarly journals Data assimilation for volcanic ash plumes using a satellite observational operator: a case study on the 2010 Eyjafjallajökull volcanic eruption

2017 ◽  
Vol 17 (2) ◽  
pp. 1187-1205 ◽  
Author(s):  
Guangliang Fu ◽  
Fred Prata ◽  
Hai Xiang Lin ◽  
Arnold Heemink ◽  
Arjo Segers ◽  
...  
Keyword(s):  
Data Assimilation ◽  
Volcanic Ash ◽  
Three Dimensional ◽  
Forecast Accuracy ◽  
Improve Model ◽  
Powerful Approach ◽  
Using Data ◽  
D Model

Abstract. Using data assimilation (DA) to improve model forecast accuracy is a powerful approach that requires available observations. Infrared satellite measurements of volcanic ash mass loadings are often used as input observations for the assimilation scheme. However, because these primary satellite-retrieved data are often two-dimensional (2-D) and the ash plume is usually vertically located in a narrow band, directly assimilating the 2-D ash mass loadings in a three-dimensional (3-D) volcanic ash model (with an integral observational operator) can usually introduce large artificial/spurious vertical correlations.In this study, we look at an approach to avoid the artificial vertical correlations by not involving the integral operator. By integrating available data of ash mass loadings and cloud top heights, as well as data-based assumptions on thickness, we propose a satellite observational operator (SOO) that translates satellite-retrieved 2-D volcanic ash mass loadings to 3-D concentrations. The 3-D SOO makes the analysis step of assimilation comparable in the 3-D model space.Ensemble-based DA is used to assimilate the extracted measurements of ash concentrations. The results show that satellite DA with SOO can improve the estimate of volcanic ash state and the forecast. Comparison with both satellite-retrieved data and aircraft in situ measurements shows that the effective duration of the improved volcanic ash forecasts for the distal part of the Eyjafjallajökull volcano is about 6 h.

The Mannich Reaction Between Aromatic Ketones, Aromatic Aldehydes and Aromatic Amines

Synthesis ◽  
1991 ◽  
Vol 1991 (09) ◽  
pp. 717-718 ◽  
Author(s):  
Yi Lin ◽  
Lei Huangshu ◽  
Zou Junhua ◽  
Xu Xiujuan
Keyword(s):  
Mannich Reaction ◽  
Aromatic Amines ◽  
Aromatic Aldehydes ◽  
Aromatic Ketones ◽  
The Mannich Reaction
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