Cobalt(II)-Catalyzed Activation of C(sp3)–H Bonds: Organic Oxidant Enabled Selective Functionalization

ACS Catalysis ◽  
2022 ◽  
pp. 1650-1656
Author(s):  
He Zhang ◽  
Meng-Chan Sun ◽  
Dandan Yang ◽  
Tong Li ◽  
Mao-Ping Song ◽  
...  
2010 ◽  
Vol 38 (1) ◽  
pp. 80-98 ◽  
Author(s):  
M. Gerster ◽  
C. Fagouri ◽  
E. Peregi

Abstract One challenge facing green tire technology is to achieve good silica hydrophobation/dispersion within the polymer matrix without a detrimental increase in the rubber compound’s viscosity during compounding. This phenomenon is well known to be induced by premature and unwanted coupling and/or crosslinking of the traditional coupling agents. The current state-of-the-art polysulfides silanes, bis(3-triethoxysilylpropyl)tetrasulfide and to a lesser extent bis(3-triethoxysilylpropyl)disulfide (“Product Application—VP Si 75/VP X 75-S in the Rubber Industry,” Degussa Hüls Report No. PA 723.1E), need to be carefully incorporated with careful temperature control during the rubber compounding to prevent this “scorchy” behavior. This paper will present novel monofunctional silanes which are suited for preparing highly silica-loaded rubber compounds of superior processability, while applying fewer mixing passes, thereby reducing mixing times which can lead to improved productivity and cost savings. Additionally, these safer coupling agents can be processed at higher temperatures which can, again, lead to reduced mixing time and better ethanol removal thereby improving the tire’s physical properties and reducing the volatile organic compounds generated during the tire’s use. The rubber compounds produced using these monofunctional silanes are characterized by lower Mooney viscosity and improved processability. Advantageously, within these novel chemical classes of coupling agents, selective functionalization of the silanes allows production of tailor-made coupling agents which can respond to the specific requirements of the tire industry (Vilgis, T. A. and Heinrich, G., “Die Physic des Autoreifens,” Physikalische Blätter, Vol. 57, 2001, pp. 1–7).


2019 ◽  
Author(s):  
Sandeep Pimparkar ◽  
Trisha Bhattacharya ◽  
Arun Maji ◽  
Argha Saha ◽  
Ramasamy Jayarajan ◽  
...  

The significance of site selective functionalization stands upon the superior selectivity, easy synthesis and diverse product utility. In this work we demonstrate the <i>para</i>-selective introduction of versatile nitrile moiety, enabled by detachable and reusable H-bonded auxiliary. The methodology holds its efficiency irrespective of substrate electronic bias. The conspicuous shift in the step energetics was probed by both experimental and computational mechanistic tools heralds the inception of <i>para</i>-deuteration. The synthetic impact of the methodology was highlighted with reusability of directing group and post synthetic modifications


2019 ◽  
Author(s):  
Sandeep Pimparkar ◽  
Trisha Bhattacharya ◽  
Arun Maji ◽  
Argha Saha ◽  
Ramasamy Jayarajan ◽  
...  

The significance of site selective functionalization stands upon the superior selectivity, easy synthesis and diverse product utility. In this work we demonstrate the <i>para</i>-selective introduction of versatile nitrile moiety, enabled by detachable and reusable H-bonded auxiliary. The methodology holds its efficiency irrespective of substrate electronic bias. The conspicuous shift in the step energetics was probed by both experimental and computational mechanistic tools heralds the inception of <i>para</i>-deuteration. The synthetic impact of the methodology was highlighted with reusability of directing group and post synthetic modifications


2020 ◽  
Author(s):  
Bapurao Bhoge ◽  
Ishu Saraogi

Chemo- and site-specific modifications in oligonucleotides have wide applicability as mechanistic probes in chemical biology. Here we have employed a classical reaction in organic chemistry, reductive amination, to selectively functionalize the N<sup>2</sup>-amine of guanine/2’-deoxyguanine monophosphate. This method specifically modifies guanine in several tested DNA oligonucleotides, while leaving the other bases unaffected. Using this approach, we have successfully incorporated desired handles chemoselectively into DNA oligomers.


2021 ◽  
Author(s):  
Mathias O. Senge ◽  
Natalia N. Sergeeva ◽  
Karl J. Hale

The development of porphyrin synthesis is illustrated, using classic and modern-day examples, which attempt to provide insights, including mechanistic ones, into the most used methods for porphyrin ring-construction and selective functionalization.


Author(s):  
Zdravko Dzambaski ◽  
Aleksandra Bondzic ◽  
Ierasia Triandafillidi ◽  
Christoforos Kokotos ◽  
Bojan Bondzic
Keyword(s):  

RSC Advances ◽  
2021 ◽  
Vol 11 (34) ◽  
pp. 20859-20864
Author(s):  
Pramodkumar D. Jadhav ◽  
Jianheng Shen ◽  
Peta-Gaye Burnett ◽  
Jian Yang ◽  
Ramaswami Sammynaiken ◽  
...  

One step regioselective methionine epimerization in cyclic peptides followed by selective functionalization leads to chemical novelty.


ACS Nano ◽  
2012 ◽  
Vol 6 (10) ◽  
pp. 9214-9220 ◽  
Author(s):  
Winand Slingenbergh ◽  
Sanne K. de Boer ◽  
Thorben Cordes ◽  
Wesley R. Browne ◽  
Ben L. Feringa ◽  
...  

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