Enantioselective synthesis and selective functionalization of 4‐aminotetrahydroquinolines as novel GLP‐1 secretagogues

Chirality ◽  
2021 ◽  
Author(s):  
Mustafa Z. Kazancioglu ◽  
Kevin Quirion ◽  
Peter Wipf ◽  
Erin M. Skoda
Keyword(s):  
Enantioselective Synthesis ◽  
Selective Functionalization

Catalytic enantioselective synthesis of indolizino[8,7-b]indole alkaloid derivatives based on the tandem reaction of tertiary enamides

2021 ◽  
Author(s):  
Xin-Ming Xu ◽  
Ming Xie ◽  
Jiazhu Li ◽  
Mei-Xiang Wang
Keyword(s):  
Indole Alkaloid ◽  
Enantioselective Synthesis ◽  
High Yield ◽  
Tandem Reaction ◽  
Indole Derivatives

An exquisite Pybox/Cu(OTf)2-catalyzed asymmetric tandem reaction of tertiary enamides was developed, which enabled the expeditious synthesis of indolizino[8,7-b]indole derivatives in high yield, excellent enantioselectivity and diastereoselectivity.

Novel Coupling Agents for Silica-filled Rubbers with Superior Processing Safety and Improved Hysteresis of the Vulcanizates

2010 ◽  
Vol 38 (1) ◽  
pp. 80-98 ◽  
Author(s):  
M. Gerster ◽  
C. Fagouri ◽  
E. Peregi
Keyword(s):  
Mixing Time ◽  
Cost Savings ◽  
Coupling Agents ◽  
Tire Industry ◽  
Selective Functionalization ◽  
Current State ◽  
Rubber Compounds ◽  
Volatile Organic ◽  
Filled Rubbers ◽  
Ethanol Removal

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).

para-Selective Cyanation of Arenes by H-Bonded Template

2019 ◽  
Author(s):  
Sandeep Pimparkar ◽  
Trisha Bhattacharya ◽  
Arun Maji ◽  
Argha Saha ◽  
Ramasamy Jayarajan ◽  
...  
Keyword(s):  
Selective Functionalization ◽  
Directing Group ◽  
Product Utility ◽  
Site Selective

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

para-Selective Cyanation of Arenes by H-Bonded Template

2019 ◽  
Author(s):  
Sandeep Pimparkar ◽  
Trisha Bhattacharya ◽  
Arun Maji ◽  
Argha Saha ◽  
Ramasamy Jayarajan ◽  
...  
Keyword(s):  
Selective Functionalization ◽  
Directing Group ◽  
Product Utility ◽  
Site Selective

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

Selective Functionalization at N2-Position of Guanine in Oligonucleotides via Reductive Amination

2020 ◽  
Author(s):  
Bapurao Bhoge ◽  
Ishu Saraogi
Keyword(s):  
Organic Chemistry ◽  
Chemical Biology ◽  
Reductive Amination ◽  
The Other ◽  
Dna Oligomers ◽  
Site Specific ◽  
Wide Applicability ◽  
Dna Oligonucleotides ◽  
Selective Functionalization

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.

Enantioselective Synthesis of Azamerone

2018 ◽  
Author(s):  
Matthew L. Landry ◽  
Grace McKenna ◽  
Noah Burns
Keyword(s):  
Late Stage ◽  
Cross Coupling ◽  
Enantioselective Synthesis ◽  
Selective Synthesis

A concise and selective synthesis of the dichlorinated meroterpenoid azamerone is described. The paucity of tactics for the synthesis of chiral organochlorides motivated the development of unique strategies for accessing these motifs in enantioenriched forms. The route features a novel enantioselective chloroetherification reaction, a Pd-catalyzed cross-coupling between a quinone diazide and a boronic hemiester, and a late-stage tetrazine [4+2]-cycloaddition/oxidation cascade.

Modular, Stereocontrolled Cβ–H/Cα–C Activation of Alkyl Carboxylic Acids

2019 ◽  
Author(s):  
Ming Shang ◽  
Karla S. Feu ◽  
Julien C. Vantourout ◽  
Lisa M. Barton ◽  
Heather L. Osswald ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Heterocyclic Compounds ◽  
Cross Coupling ◽  
Building Blocks ◽  
Enantioselective Synthesis ◽  
Carbon Centers ◽  
Drug Candidates ◽  
Rapid Diversification ◽  
Directing Group ◽  
Compound Series

<div> <div> <div> <p>The union of two powerful transformations, directed C–H activation and decarboxylative cross-coupling, for the enantioselective synthesis of vicinally functionalized alkyl, carbocyclic, and heterocyclic compounds is described. Starting from simple carboxylic acid building blocks, this modular sequence exploits the residual directing group to access more than 50 scaffolds that would be otherwise extremely difficult to prepare. The tactical use of these two transformations accomplishes a formal vicinal difunctionalization of carbon centers in a way that is modular and thus amenable to rapid diversity incorporation. A simplification of routes to known preclinical drug candidates is presented along with the rapid diversification of an antimalarial compound series. </p> </div> </div> </div>

Enantioselective Synthesis of Azamerone

2018 ◽  
Author(s):  
Matthew L. Landry ◽  
Grace McKenna ◽  
Noah Burns
Keyword(s):  
Late Stage ◽  
Cross Coupling ◽  
Enantioselective Synthesis ◽  
Selective Synthesis

A concise and selective synthesis of the dichlorinated meroterpenoid azamerone is described. The paucity of tactics for the synthesis of chiral organochlorides motivated the development of unique strategies for accessing these motifs in enantioenriched forms. The route features a novel enantioselective chloroetherification reaction, a Pd-catalyzed cross-coupling between a quinone diazide and a boronic hemiester, and a late-stage tetrazine [4+2]-cycloaddition/oxidation cascade.

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