Mechanistic investigation of N-heterocyclic carbene and Na2CO3 cooperatively catalyzed C(sp3)-F bond activation reaction of fluoroenal

2020 ◽  
Vol 489 ◽  
pp. 110944 ◽  
Author(s):  
Yang Wang ◽  
Donghui Wei
Keyword(s):  
Bond Activation ◽  
Activation Reaction ◽  
Mechanistic Investigation

Theoretical and experimental studies of palladium-catalyzed site-selective C(sp3)−H bond functionalization enabled by transient ligands

2017 ◽  
Author(s):  
Haibo Ge ◽  
Lei Pan ◽  
Piaoping Tang ◽  
Ke Yang ◽  
Mian Wang ◽  
...  
Keyword(s):  
Bond Activation ◽  
Theoretical Calculations ◽  
Experimental Studies ◽  
Bond Functionalization ◽  
Aliphatic Ketones ◽  
Site Selectivity ◽  
Mechanistic Investigation ◽  
Palladium Catalyzed ◽  
Metal Catalyzed ◽  
Site Selective

Transition metal-catalyzed selective C–H bond functionalization enabled by transient ligands has become an extremely attractive topic due to its economical and greener characteristics. However, catalytic pathways of this reaction process on unactivated sp<sup>3</sup> carbons of reactants have not been well studied yet. Herein, detailed mechanistic investigation on Pd-catalyzed C(sp<sup>3</sup>)–H bond activation with amino acids as transient ligands has been systematically conducted. The theoretical calculations showed that higher angle distortion of C(sp2)-H bond over C(sp3)-H bond and stronger nucleophilicity of benzylic anion over its aromatic counterpart, leading to higher reactivity of corresponding C(sp<sup>3</sup>)–H bonds; the angle strain of the directing rings of key intermediates determines the site-selectivity of aliphatic ketone substrates; replacement of glycine with β-alanine as the transient ligand can decrease the angle tension of the directing rings. Synthetic experiments have confirmed that β-alanine is indeed a more efficient transient ligand for arylation of β-secondary carbons of linear aliphatic ketones than its glycine counterpart.<br><br>

Cu-catalyzed C–H Activation Reaction: One Pot Direct Synthesis of Xanthine and Uric Acid Derivatives from 5-Bromo Uracil

Synlett ◽  
2021 ◽  
Author(s):  
Habibur Rahaman ◽  
Brindaban Roy ◽  
Somjit Hazra ◽  
Biplab Mondal
Keyword(s):  
Uric Acid ◽  
Bond Activation ◽  
Direct Synthesis ◽  
One Pot ◽  
Activation Reaction

Abstract: A one pot direct synthesis of xanthine and uric acid derivates is reported. This simple yet efficient methodology illustrates concurrent formation of two C-N bonds using CuBr2 as catalyst and one of those C-N bonds is formed by uracil C6-H bond activation.

scholarly journals Rh-catalyzed decarbonylation of conjugated ynones via carbon–alkyne bond activation: reaction scope and mechanistic exploration via DFT calculations

2015 ◽  
Vol 6 (5) ◽  
pp. 3201-3210 ◽  
Author(s):  
Alpay Dermenci ◽  
Rachel E. Whittaker ◽  
Yang Gao ◽  
Faben A. Cruz ◽  
Zhi-Xiang Yu ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Bond Activation ◽  
Activation Reaction

We report a catalytic C–C bond activation of unstrained conjugated monoynonesviadecarbonylation to synthesize disubstituted alkynes.

scholarly journals A Detailed Kinetico-Mechanistic Investigation on the Palladium C–H Bond Activation in Azobenzenes and Their Monopalladated Derivatives

2020 ◽  
Vol 59 (23) ◽  
pp. 17123-17133
Author(s):  
Alen Bjelopetrović ◽  
Dajana Barišić ◽  
Zrinka Duvnjak ◽  
Ivan Džajić ◽  
Marina Juribašić Kulcsár ◽  
...  
Keyword(s):  
Bond Activation ◽  
Mechanistic Investigation

scholarly journals Femtosecond Infrared Studies of Chemical Bond Activation

1999 ◽  
Vol 19 (1-4) ◽  
pp. 253-262 ◽  
Author(s):  
M. C. Asplund ◽  
H. Yang ◽  
K. T. Kotz ◽  
S. E. Bromberg ◽  
M. J. Wilkens ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Chemical Bond ◽  
Bond Activation ◽  
Product Formation ◽  
Organometallic Complexes ◽  
Activation Time ◽  
Activation Reaction ◽  
Infrared Studies ◽  
Important Intermediate ◽  
Solvent Complex

The identification of the intermediates observed in bond activation reactions involving organometallic complexes on time scales from femtoseconds to milliseconds has been accomplished through the use of ultrafast infrared spectroscopy. C—H bond activation by the molecule Tp*Rh(CO)2 showed a final activation time of 200 ns in cyclic solvents, indicating a reaction barrier of 8.3 kcal/mol. An important intermediate is the partially dechelated η2-Tp*Rh(CO)(S) solvent complex, which was formed 200 ps after the initial photoexcitation. Si—H bond activation by CpM(CO)3 (M=Mn, Re) showed some product formation in less than 5 ps, indicating that the Si—H activation reaction is barrierless. The activated product was formed on several timescales, from picoseconds to nanoseconds, suggesting that there are different pathways for forming final product which are partitioned by the initial photoexcitation.

Mechanistic investigation of vinylic carbon–fluorine bond activation of perfluorinated cycloalkenes using Cp*2ZrH2 and Cp*2ZrHF

2010 ◽  
Vol 131 (11) ◽  
pp. 1122-1132 ◽  
Author(s):  
Bradley M. Kraft ◽  
Eric Clot ◽  
Odile Eisenstein ◽  
William W. Brennessel ◽  
William D. Jones
Keyword(s):  
Bond Activation ◽  
Mechanistic Investigation
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