scholarly journals Electrophilic Substitution of Thiophenes with Arylpalladium(II) and Platinum(II) Complexes: Mechanistic Studies on Palladium-Catalyzed CH Arylation of Thiophenes

2009 ◽  
Vol 82 (5) ◽  
pp. 555-562 ◽  
Author(s):  
Atsushi Sugie ◽  
Hirotoshi Furukawa ◽  
Yuji Suzaki ◽  
Kohtaro Osakada ◽  
Munetaka Akita ◽  
...  
2017 ◽  
Vol 8 (4) ◽  
pp. 2841-2851 ◽  
Author(s):  
Yining Ji ◽  
Hongming Li ◽  
Alan M. Hyde ◽  
Qinghao Chen ◽  
Kevin M. Belyk ◽  
...  

Detailed mechanistic studies of a Pd-catalyzed asymmetric C–N coupling led to a rational design of a new series of bis-phosphine mono-oxides ligated Pd(ii) pre-catalysts that allow for reliable and complete catalyst activation.


2020 ◽  
Vol 142 (7) ◽  
pp. 3564-3576 ◽  
Author(s):  
Antoine de Gombert ◽  
Alasdair I. McKay ◽  
Christopher J. Davis ◽  
Katherine M. Wheelhouse ◽  
Michael C. Willis

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Shaoyu Mai ◽  
Wendong Li ◽  
Xue Li ◽  
Yingwei Zhao ◽  
Qiuling Song

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.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhi-Tao He ◽  
John F. Hartwig

Abstract Small, strained rings have rigid, defined conformations and unique electronic properties. For these reasons, many groups seek to use these subunits to form biologically active molecules. We report a generally applicable approach to attach small rings to a wide range of aromatic compounds by palladium-catalyzed α-arylation of cyclopropyl, cyclobutyl and azetidinyl esters. The direct α-arylation of cyclopropyl esters and cyclobutyl esters is achieved in high yield by ensuring that the rate of coupling exceeds the rate of Claisen condensation. The α-arylation of azetidines is achieved without ring opening of the strained saturated heterocycle by conducting the reactions with an azetidine derivative bearing a benzyl protecting group on nitrogen. Mechanistic studies show that the α-arylation of small rings is challenging because of the weak acidity of α C-H bond (cyclopropanes), strong sensitivity of the strained esters to Claisen condensation (cyclobutatanes), or facile decomposition of the enolates (azetidinyl esters).


ACS Catalysis ◽  
2014 ◽  
Vol 4 (7) ◽  
pp. 2395-2401 ◽  
Author(s):  
Devin M. Ferguson ◽  
Stacey R. Rudolph ◽  
Dipannita Kalyani

2017 ◽  
Vol 2017 (28) ◽  
pp. 4168-4174 ◽  
Author(s):  
Atanu Modak ◽  
Sujoy Rana ◽  
Ashwini K. Phukan ◽  
Debabrata Maiti

2017 ◽  
Vol 13 ◽  
pp. 2610-2616 ◽  
Author(s):  
Tao Fan ◽  
Wei-Dong Meng ◽  
Xingang Zhang

An efficient palladium-catalyzed Heck-type reaction of secondary trifluoromethylated alkyl bromides has been developed. The reaction proceeds under mild reaction conditions with high efficiency and excellent functional group tolerance, even towards formyl and hydroxy groups. Preliminary mechanistic studies reveal that a secondary trifluoromethylated alkyl radical is involved in the reaction.


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