N-Heterocyclic Carbene-Catalyzed [4 + 2] Cyclization of Saturated Carboxylic Acid with o-Quinone Methides through in Situ Activation: Enantioselective Synthesis of Dihydrocoumarins

2017 ◽  
Vol 82 (3) ◽  
pp. 1790-1795 ◽  
Author(s):  
Yuanfeng Wang ◽  
Jian Pan ◽  
Jingjiao Dong ◽  
Chenxia Yu ◽  
Tuanjie Li ◽  
...  
2020 ◽  
Vol 56 (3) ◽  
pp. 439-442 ◽  
Author(s):  
Yong You ◽  
Ting-Ting Li ◽  
Shu-Pei Yuan ◽  
Ke-Xin Xie ◽  
Zhen-Hua Wang ◽  
...  

An asymmetric [4+2] cycloaddition of 1-((2-aryl)vinyl)naphthalen-2-ols with in situ generated ortho-quinone methides enables the highly enantioselective synthesis of polysubstituted chromanes.


2015 ◽  
Vol 51 (8) ◽  
pp. 1461-1464 ◽  
Author(s):  
Satyajit Saha ◽  
Santosh Kumar Alamsetti ◽  
Christoph Schneider

Hydrogen-bonded, in situ-generated ortho-quinone methides undergo highly enantioselective Friedel–Crafts reactions with indoles and naphthols under mild reaction conditions.


2018 ◽  
Vol 9 (22) ◽  
pp. 4992-4998 ◽  
Author(s):  
Fengchang Cheng ◽  
Wenxin Lu ◽  
Wei Huang ◽  
Lu Wen ◽  
Mingfeng Li ◽  
...  

Catalytic chemo- and enantioselective generation of tertiary benzylic copper complexes from Cu–B(pin) (pin = pinacolato) additions to 1,1-disubstituted alkenes followed by in situ reactions with ketones and carboxylic acid phenol esters to construct multifunctional alkylboron compounds that contain quaternary stereogenic centers is presented.


2018 ◽  
Author(s):  
Roshna Vakkeel ◽  
Aleeza Farrukh ◽  
Aranzazu del Campo

In order to study how dynamic changes of α5β1 integrin engagement affect cellular behaviour, photoactivatable derivatives of α5β1 specific ligands are presented in this article. The presence of the photoremovable protecting group (PRPG) introduced at a relevant position for integrin recognition, temporally inhibits ligand bioactivity. Light exposure at cell-compatible dose efficiently cleaves the PRPG and restores functionality. Selective cell response (attachment, spreading, migration) to the activated ligand on the surface is achieved upon controlled exposure. Spatial and temporal control of the cellular response is demonstrated, including the possibility to in situ activation. Photoactivatable integrin-selective ligands in model microenvironments will allow the study of cellular behavior in response to changes in the activation of individual integrins as consequence of dynamic variations of matrix composition.


2019 ◽  
Author(s):  
Ming Shang ◽  
Karla S. Feu ◽  
Julien C. Vantourout ◽  
Lisa M. Barton ◽  
Heather L. Osswald ◽  
...  

<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>


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