scholarly journals A biomimetic S H 2 cross-coupling mechanism for quaternary sp 3 -carbon formation

Science ◽  
2021 ◽  
Vol 374 (6572) ◽  
pp. 1258-1263
Author(s):  
Wei Liu ◽  
Marissa N. Lavagnino ◽  
Colin A. Gould ◽  
Jesús Alcázar ◽  
David W. C. MacMillan
Keyword(s):  
Cross Coupling ◽  
Coupling Mechanism ◽  
Carbon Formation

Photoredox Nickel-Catalyzed C–S Cross-Coupling: Mechanism, Kinetics, and Generalization

2021 ◽  
Vol 143 (4) ◽  
pp. 2005-2015
Author(s):  
Yangzhong Qin ◽  
Rui Sun ◽  
Nikolas P. Gianoulis ◽  
Daniel G. Nocera
Keyword(s):  
Cross Coupling ◽  
Coupling Mechanism

scholarly journals Synthesis of aryl sulfides via radical–radical cross coupling of electron-rich arenes using visible light photoredox catalysis

2018 ◽  
Vol 14 ◽  
pp. 2520-2528 ◽  
Author(s):  
Amrita Das ◽  
Mitasree Maity ◽  
Simon Malcherek ◽  
Burkhard König ◽  
Julia Rehbein
Keyword(s):  
Visible Light ◽  
Experimental Evidence ◽  
Blue Light ◽  
Room Temperature ◽  
Cross Coupling ◽  
Light Irradiation ◽  
Coupling Mechanism ◽  
Photoredox Catalysis ◽  
Reaction Proceeds ◽  
Aryl Sulfides

Electron-rich arenes react with aryl and alkyl disulfides in the presence of catalytic amounts of [Ir(dF(CF3)ppy)2(dtbpy)]PF6 and (NH4)2S2O8 under blue light irradiation to yield arylthiols. The reaction proceeds at room temperature and avoids the use of prefunctionalized arenes. Experimental evidence suggests a radical–radical cross coupling mechanism.

Cross-coupling synchronous velocity control using model reference adaptive control scheme in an unsymmetrical biaxial winding system

2018 ◽  
Vol 232 (9) ◽  
pp. 1245-1259
Author(s):  
Huy Hung Nguyen ◽  
Van Tu Duong ◽  
Dae Hwan Kim ◽  
Hak Kyeong Kim ◽  
Sang Bong Kim
Keyword(s):  
Adaptive Control ◽  
Cross Coupling ◽  
Model Reference Adaptive Control ◽  
Coupling Mechanism ◽  
Unknown Parameters ◽  
Model Reference ◽  
Motion Error ◽  
Control Scheme ◽  
Model Reference Adaptive ◽  
Adaptive Control Scheme

Motion control with high accuracy for each axial system is the fundamental requirement to reduce a synchronous motion error of a multi-axis system. Especially, designing a model-based controller for an uncertainty system with unknown parameters is not easy without using system identification. To overcome the mentioned issue, this article proposes a cross-coupling synchronous velocity controller using a backstepping-based model reference adaptive control scheme in an unsymmetrical biaxial winding system called a transformer winding system. The proposed controller deals not only with the uncertainty but also with the recursive structure of the system. The backstepping technique for the recursive structural system and the model reference adaptive control method for the uncertainty of the system are designed to stabilize two axial systems with unknown parameters. An auxiliary system is added to build the proposed controller for coping with input constraints of physical actuators. To improve the proposed controller’s ability to cope with external disturbances, a dead-zone modification is utilized to modify the adaptation laws to avoid the drift phenomenon. Moreover, a cross-coupling mechanism is integrated into the proposed controller to reduce the synchronous velocity error between the velocities of the biaxial winding system. The proposed controller is also transformed into discrete time to be run on a digital signal processor alone chip. The experimental results are shown to verify the high performance and efficiency of the proposed controller for practical applications.

Photoredox/Pd dual-catalytic three-component cross-coupling

2020 ◽  
Author(s):  
Logan Forshee ◽  
Kaitie Cartwright ◽  
Jon Tunge ◽  
Megan Hegarty
Keyword(s):  
Cross Coupling
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