Role of Lewis acid additives in a palladium catalyzed directed C–H functionalization reaction of benzohydroxamic acid to isoxazolone

2017 ◽  
Vol 15 (1) ◽  
pp. 246-255 ◽  
Author(s):  
C. Athira ◽  
Raghavan B. Sunoj
Keyword(s):  
Lewis Acid ◽  
Pivalic Acid ◽  
Bond Functionalization ◽  
Benzohydroxamic Acid ◽  
Palladium Catalyzed ◽  
Functionalization Reaction

The role of additives, pivalic acid and ZnCl2, in a Pd-catalyzed directed C–H bond functionalization reaction is established.

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>

ChemInform Abstract: Palladium Catalyzed Csp2-H Activation for Direct Aryl Hydroxylation: The Unprecedented Role of 1,4-Dioxane as a Source of Hydroxyl Radicals.

ChemInform ◽  
2015 ◽  
Vol 46 (22) ◽  
pp. no-no
Author(s):  
Kapileswar Seth ◽  
Manesh Nautiyal ◽  
Priyank Purohit ◽  
Naisargee Parikh ◽  
Asit K. Chakraborti
Keyword(s):  
Hydroxyl Radicals ◽  
Palladium Catalyzed

Lewis Acid Catalyzed Benzylic C-H Bond Functionalization of Azaarenes; Addition to Imines and Enones

Synthesis ◽  
2012 ◽  
Vol 44 (14) ◽  
pp. 2185-2194 ◽  
Author(s):  
Shigeki Matsunaga ◽  
Motomu Kanai ◽  
Hirotomo Komai ◽  
Tatsuhiko Yoshino
Keyword(s):  
Lewis Acid ◽  
Bond Functionalization ◽  
Acid Catalyzed

Critical role of Bronsted acid in Lewis-acid-catalyzed synthesis of Amadori and Heyns compounds of β-amino acids

2021 ◽  
pp. 1-11
Author(s):  
Debasree Chanda ◽  
Gangothri M. Venkataswamy ◽  
Lagamawwa V. Hipparagi ◽  
Nanishankar V. Harohally
Keyword(s):  
Amino Acids ◽  
Lewis Acid ◽  
Critical Role ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Brönsted Acid ◽  
Acid Catalyzed

ChemInform Abstract: High Diastereoselectivity in Hosomi-Sakurai Reaction on Metal-Complexed Acyclic Enones: Role of Out-of-Plane Coordination of Lewis Acid.

ChemInform ◽  
2010 ◽  
Vol 33 (8) ◽  
pp. no-no
Author(s):  
Surojit Sur ◽  
Sunil K. Mandal ◽  
Sambasivam Ganesh ◽  
Vedavati Puranik ◽  
Amitabha Sarkar
Keyword(s):  
Lewis Acid ◽  
Out Of Plane

scholarly journals Palladium-catalyzed cross coupling reactions of 4-bromo-6H-1,2-oxazines

2009 ◽  
Vol 5 ◽  
Author(s):  
Reinhold Zimmer ◽  
Elmar Schmidt ◽  
Michal Andrä ◽  
Marcel-Antoine Duhs ◽  
Igor Linder ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Cross Coupling ◽  
Pyridine Derivative ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed

A number of 4-aryl- and 4-alkynyl-substituted 6H-1,2-oxazines 8 and 9 have been prepared in good yields via cross coupling reactions of halogenated precursors 2, which in turn are easily accessible by bromination of 6H-1,2-oxazines 1. Lewis-acid promoted reaction of 1,2-oxazine 9c with 1-hexyne provided alkynyl-substituted pyridine derivative 12 thus demonstrating the potential of this approach for the synthesis of pyridines.

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