scholarly journals Synthesis of Imidazolium Precursors for the Hydroxyl-Group-Modified N-Heterocyclic Carbenes and Applications of the in situ Generated Carbene Ligands in Suzuki-Miyaura and Sonogashira Coupling Reactions

2017 ◽  
Vol 37 (5) ◽  
pp. 1258
Author(s):  
Yali Bai ◽  
Xiaowei Li ◽  
Xuedong Xiao ◽  
Jiaqi Liu ◽  
Junjuan Yang ◽  
...  
Keyword(s):  
Heterocyclic Carbenes ◽  
Hydroxyl Group ◽  
Coupling Reactions ◽  
Sonogashira Coupling ◽  
Carbene Ligands

N-Heterocyclic carbene ligands bearing poly(ethylene glycol) chains: effect of the chain length on palladium-catalyzed coupling reactions employing aryl chlorides

2015 ◽  
Vol 51 (98) ◽  
pp. 17382-17385 ◽  
Author(s):  
Tetsuaki Fujihara ◽  
Takahiro Yoshikawa ◽  
Motoi Satou ◽  
Hidetoshi Ohta ◽  
Jun Terao ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Chain Length ◽  
Heterocyclic Carbenes ◽  
Coupling Reactions ◽  
Poly Ethylene Glycol ◽  
Carbene Ligands ◽  
Aryl Chlorides ◽  
Palladium Catalyzed ◽  
Poly Ethylene

N-Heterocyclic carbenes bearing poly(ethylene glycol) chains of different lengths have been employed as ligands in palladium-catalyzed coupling reactions of aryl chlorides.

scholarly journals Specialized Olefin Metathesis Catalysts Featuring Unsymmetrical N-Heterocyclic Carbene Ligands Bearing N-(Fluoren-9-yl) Arm

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 599 ◽  
Author(s):  
Phillip I. Jolly ◽  
Anna Marczyk ◽  
Paweł Małecki ◽  
Damian Trzybiński ◽  
Krzysztof Woźniak ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Olefin Metathesis ◽  
High Selectivity ◽  
State Of The Art ◽  
Heterocyclic Carbenes ◽  
Carbene Ligands ◽  
Structural Motifs ◽  
In Situ Generation ◽  
Metathesis Catalysts

Beneficial structural motifs from two known state-of-the-art olefin metathesis catalysts types, bearing unsymmetrical N-heterocyclic carbenes (uNHCs), were combined into a new hybridized design thereby translating the complementary beneficial reactivity demonstrated by their ‘parent’ complexes to the new N-fluorene derived olefin metathesis catalysts. Two chelating 2-iso-propoxy-benzylidene (Hoveyda-type) and two 3-phenyl-1H-inden-1-ylidene (indenylidene-type) complexes were successfully prepared by in situ generation of either the N′-mesityl (Mes) or N′-diisopropylphenyl (Dipp) derived uNHCs taking advantage of the thermal decomposition of the corresponding 2-(penta-fluorophenyl)-imidazolidines (NHC adducts). The new fluorene-derived catalysts mediate challenging olefin metathesis processes, such as α-olefin self-metathesis, with high selectivity and conversion.

Nitrile-functionalized pyrrolidinium ionic liquids as solvents for cross-coupling reactions involving in situ generated nanoparticlecatalyst reservoirs

2010 ◽  
Vol 12 (8) ◽  
pp. 1834-1841 ◽  
Author(s):  
Yugang Cui ◽  
Ilaria Biondi ◽  
Manish Chaubey ◽  
Xue Yang ◽  
Zhaofu Fei ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Cross Coupling Reactions

scholarly journals Asymmetric Pd-NHC*-catalyzed coupling reactions

2012 ◽  
Vol 84 (8) ◽  
pp. 1741-1748 ◽  
Author(s):  
E. Peter Kündig ◽  
Yixia Jia ◽  
Dmitry Katayev ◽  
Masafumi Nakanishi
Keyword(s):  
High Temperature ◽  
Coupling Reactions ◽  
Structural Studies ◽  
Methylene Unit ◽  
Asymmetric Coupling ◽  
New Applications ◽  
Very High

Very high asymmetric inductions result in the Pd-catalyzed intramolecular arylation of amides to give 3,3-disubstituted oxindoles when new in situ-generated chiral N-heterocyclic carbene (NHC*) ligands are employed. Structural studies show that conformational locking to minimize allylic strain is the key to understanding the function of these ligands. New applications of these ligands in the frontier area of asymmetric coupling reactions involving C(sp3)–H bonds are detailed. Highly enantioenriched fused indolines are accessible using either preformed- or in situ-generated Pd-NHC* catalysts. Remarkably, this occurs at high temperature (140–160 °C) via excellent asymmetric recognition of an enantiotopic C–H bond in an unactivated methylene unit.

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