Kinetic energy release distributions as a probe of transition-metal-mediated hydrogen-hydrogen, carbon-hydrogen, and carbon-carbon bond formation processes: reactions of cobalt and nickel ions with alkanes

1988 ◽  
Vol 110 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Maureen A. Hanratty ◽  
J. L. Beauchamp ◽  
Andreas J. Illies ◽  
Petra. Van Koppen ◽  
M. T. Bowers
Keyword(s):  
Kinetic Energy ◽  
Transition Metal ◽  
Energy Release ◽  
Bond Formation ◽  
Kinetic Energy Release ◽  
Formation Processes ◽  
Carbon Bond ◽  
Nickel Ions ◽  
Carbon Carbon Bond ◽  
Cobalt And Nickel

Carbon Dioxide-Mediated C(sp2)–H Arylation of Primary and Secondary Benzylamines

2018 ◽  
Author(s):  
Mohit Kapoor ◽  
Pratibha Chand-Thakuri ◽  
Michael Young
Keyword(s):  
Carbon Dioxide ◽  
Transition Metal ◽  
Bond Activation ◽  
Bond Formation ◽  
Carbon Bond ◽  
Chelate Effect ◽  
Free Amine ◽  
Carbon Carbon Bond ◽  
New Strategy ◽  
Metal Catalyzed

Carbon-carbon bond formation by transition metal-catalyzed C–H activation has become an important strategy to fabricate new bonds in a rapid fashion. Despite the pharmacological importance of <i>ortho</i>-arylbenzylamines, however, effective <i>ortho</i>-C–C bond formation from C–H bond activation of free primary and secondary benzylamines using Pd<sup>II</sup> remains an outstanding challenge. Presented herein is a new strategy for constructing <i>ortho</i>-arylated primary and secondary benzylamines mediated by carbon dioxide (CO<sub>2</sub>). The use of CO<sub>2</sub> is critical to allowing this transformation to proceed under milder conditions than previously reported, and that are necessary to furnish free amine products that can be directly used or elaborated without the need for deprotection. In cases where diarylation is possible, a chelate effect is demonstrated to facilitate selective monoarylation.

scholarly journals Transition Metal-Catalyzed α-Position Carbon–Carbon Bond Formations of Carbonyl Derivatives

Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 861 ◽  
Author(s):  
Ha-Eun Lee ◽  
Dopil Kim ◽  
Ahrom You ◽  
Myung Hwan Park ◽  
Min Kim ◽  
...  
Keyword(s):  
Transition Metal ◽  
Carbonyl Compounds ◽  
Bond Formation ◽  
Chiral Ligand ◽  
Catalytic Systems ◽  
Carbon Bond ◽  
Carbonyl Derivatives ◽  
Carbon Carbon Bond ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

α-Functionalization of carbonyl compounds in organic synthesis has traditionally been accomplished via classical enolate chemistry. As α-functionalized carbonyl moieties are ubiquitous in biologically and pharmaceutically valuable molecules, catalytic α-alkylations have been extensively studied, yielding a plethora of practical and efficient methodologies. Moreover, stereoselective carbon–carbon bond formation at the α-position of achiral carbonyl compounds has been achieved by using various transition metal–chiral ligand complexes. This review describes recent advances—in the last 20 years and especially focusing on the last 10 years—in transition metal-catalyzed α-alkylations of carbonyl compounds, such as aldehydes, ketones, imines, esters, and amides and in efficient carbon–carbon bond formations. Active catalytic species and ligand design are discussed, and mechanistic insights are presented. In addition, recently developed photo-redox catalytic systems for α-alkylations are described as a versatile synthetic tool for the synthesis of chiral carbonyl-bearing molecules.

scholarly journals Metal-free visible light photoredox enables generation of carbyne equivalents via phosphonium ylide C–H activation

2019 ◽  
Vol 10 (6) ◽  
pp. 1687-1691 ◽  
Author(s):  
Mrinmoy Das ◽  
Minh Duy Vu ◽  
Qi Zhang ◽  
Xue-Wei Liu
Keyword(s):  
Visible Light ◽  
Bond Formation ◽  
Formation Processes ◽  
New Approach ◽  
Carbon Bond ◽  
Metal Free ◽  
Carbon Carbon Bond ◽  
Carbon Carbon Bonds ◽  
Carbon Bonds ◽  
New Strategy

Phosphonium ylides have shown their synthetic usefulness in important carbon–carbon bond formation processes. Our new strategy employs phosphonium ylides as novel carbyne equivalents and features a new approach for constructing carbon–carbon bonds from alkenes.

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