Kinetic and Mechanistic Studies of Carboxylic Acid–Bisoxazoline Chain-Coupling Reactions

2003 ◽  
Vol 204 (14) ◽  
pp. 1755-1764 ◽  
Author(s):  
Laurent Néry ◽  
Hervé Lefebvre ◽  
Alain Fradet
Keyword(s):  
Carboxylic Acid ◽  
Coupling Reactions ◽  
Mechanistic Studies

scholarly journals Heterobiaryl synthesis by contractive C–C coupling via P(V) intermediates

Science ◽  
2018 ◽  
Vol 362 (6416) ◽  
pp. 799-804 ◽  
Author(s):  
Michael C. Hilton ◽  
Xuan Zhang ◽  
Benjamin T. Boyle ◽  
Juan V. Alegre-Requena ◽  
Robert S. Paton ◽  
...  
Keyword(s):  
Cross Coupling ◽  
The Other ◽  
Coupling Reactions ◽  
Mechanistic Studies ◽  
Alternative Approach ◽  
Metal Catalyzed ◽  
Polar Functional Groups ◽  
Pharmacological Function ◽  
Complex Drug ◽  
Acidic Alcohol

Heterobiaryls composed of pyridine and diazine rings are key components of pharmaceuticals and are often central to pharmacological function. We present an alternative approach to metal-catalyzed cross-coupling to make heterobiaryls using contractive phosphorus C–C couplings, also termed phosphorus ligand coupling reactions. The process starts by regioselective phosphorus substitution of the C–H bonds para to nitrogen in two successive heterocycles; ligand coupling is then triggered via acidic alcohol solutions to form the heterobiaryl bond. Mechanistic studies imply that ligand coupling is an asynchronous process involving migration of one heterocycle to the ipso position of the other around a central pentacoordinate P(V) atom. The strategy can be applied to complex drug-like molecules containing multiple reactive sites and polar functional groups, and also enables convergent coupling of drug fragments and late-stage heteroarylation of pharmaceuticals.

Nickel-Catalyzed Hydroalkenylation of Alkynes through C–F Bond Activation: Synthesis of 2-Fluoro-1,3-dienes

Synthesis ◽  
2017 ◽  
Vol 49 (16) ◽  
pp. 3569-3575 ◽  
Author(s):  
Junji Ichikawa ◽  
Yota Watabe ◽  
Kohei Kanazawa ◽  
Takeshi Fujita
Keyword(s):  
Bond Activation ◽  
Oxidative Cyclization ◽  
Coupling Reactions ◽  
Mechanistic Studies ◽  
Co Catalyst

2-Fluoro-1,3-dienes were synthesized through nickel-catalyzed coupling reactions between β,β-difluorostyrenes and alkynes in the presence of ZrF4 as co-catalyst and a hydride source derived from triethylborane and lithium isopropoxide. Mechanistic studies revealed that the carbon–fluorine bond was cleaved by β-fluorine elimination from intermediary nickelacyclopentenes generated through oxidative cyclization of the two substrates.

scholarly journals Palladium-catalyzed Suzuki-Miyaura coupling of thioureas or thioamides

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Shaoyu Mai ◽  
Wendong Li ◽  
Xue Li ◽  
Yingwei Zhao ◽  
Qiuling Song
Keyword(s):  
Silver Salt ◽  
Coupling Reaction ◽  
Coupling Reactions ◽  
Mechanistic Studies ◽  
Aromatic Rings ◽  
Cross Coupling Reactions ◽  
Broad Array ◽  
Palladium Catalyzed

AbstractCross-coupling reactions involving metal carbene intermediates play an increasingly important role in C–C bond formation. Expanding the carbene precursors to a broader range of starting materials and more diverse products is an ongoing challenge in synthetic organic chemistry. Herein, we report a Suzuki-Miyaura coupling reaction of in situ-generated Pd–carbene complexes via desulfurization of thioureas or thioamides. This strategy enables the preparation of a broad array of substituted amidinium salts and unsymmetrical diaryl ketones. The reaction is readily scalable, compatible with bromo groups on aromatic rings, tolerant to moisture and air and has a broad substrate scope. Furthermore, a single crystal structure of Pd-diaminocarbene complex is obtained and proven to be the key intermediate in both catalytic and stoichiometric reactions. Preliminary mechanistic studies demonstrate the dual role of the silver salt as a desulfurating reagent assisting the elimination of sulfur and as oxidant facilitating the PdII/Pd0/PdII catalytic cycle.

Structural and mechanistic studies of the base-induced Sommelet–Hauser rearrangement of N-α-branched benzylic azetidine-2-carboxylic acid-derived ammonium salts

2017 ◽  
Vol 15 (31) ◽  
pp. 6668-6678 ◽  
Author(s):  
Eiji Tayama ◽  
Kazutoshi Watanabe ◽  
Sho Sotome
Keyword(s):  
Carboxylic Acid ◽  
Acid Ester ◽  
Ammonium Salts ◽  
Mechanistic Studies ◽  
Carboxylic Acid Ester

The base-induced Sommelet–Hauser rearrangement of N-α-branched benzylic azetidine-2-carboxylic acid ester-derived ammonium salts was demonstrated.

Mechanistic studies of 1-aminocyclopropane-1-carboxylic acid oxidase: single turnover reaction

2004 ◽  
Vol 9 (2) ◽  
pp. 171-182 ◽  
Author(s):  
Amy M. Rocklin ◽  
Keisuke Kato ◽  
Hung-wen Liu ◽  
Lawrence Que ◽  
John D. Lipscomb
Keyword(s):  
Carboxylic Acid ◽  
Acid Oxidase ◽  
Mechanistic Studies ◽  
Single Turnover

Copper-Catalyzed Double Decarboxylative Coupling Reactions of Alkynyl Carboxylic Acid and Glyoxylic Acid: Synthesis of Propargyl Amines and Imidazopyridines

2016 ◽  
Vol 5 (6) ◽  
pp. 770-777 ◽  
Author(s):  
Jinseop Choi ◽  
Jeongah Lim ◽  
Francis Mariaraj Irudayanathan ◽  
Han-Sung Kim ◽  
Jaerim Park ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Glyoxylic Acid ◽  
Acid Synthesis ◽  
Coupling Reactions ◽  
Decarboxylative Coupling
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