Sterically Demanding, Water-Soluble Alkylphosphines as Ligands for High Activity Suzuki Coupling of Aryl Bromides in Aqueous Solvents

2001 ◽  
Vol 3 (17) ◽  
pp. 2757-2759 ◽  
Author(s):  
Kevin H. Shaughnessy ◽  
Rebecca S. Booth
Keyword(s):  
High Activity ◽  
Suzuki Coupling ◽  
Water Soluble ◽  
Aryl Bromides ◽  
Sterically Demanding

Monodentate Trialkylphosphines: Privileged Ligands in Metal-catalyzed Crosscoupling Reactions

2020 ◽  
Vol 24 (3) ◽  
pp. 231-264 ◽  
Author(s):  
Kevin H. Shaughnessy
Keyword(s):  
Transition Metal ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Aryl Bromides ◽  
Wide Range ◽  
Sterically Demanding ◽  
Transition Metal Catalyzed ◽  
Catalyzed Reactions ◽  
Metal Catalyzed

Phosphines are widely used ligands in transition metal-catalyzed reactions. Arylphosphines, such as triphenylphosphine, were among the first phosphines to show broad utility in catalysis. Beginning in the late 1990s, sterically demanding and electronrich trialkylphosphines began to receive attention as supporting ligands. These ligands were found to be particularly effective at promoting oxidative addition in cross-coupling of aryl halides. With electron-rich, sterically demanding ligands, such as tri-tertbutylphosphine, coupling of aryl bromides could be achieved at room temperature. More importantly, the less reactive, but more broadly available, aryl chlorides became accessible substrates. Tri-tert-butylphosphine has become a privileged ligand that has found application in a wide range of late transition-metal catalyzed coupling reactions. This success has led to the use of numerous monodentate trialkylphosphines in cross-coupling reactions. This review will discuss the general properties and features of monodentate trialkylphosphines and their application in cross-coupling reactions of C–X and C–H bonds.

scholarly journals Synthesis of a Novel Library of 1-Substituted Pyrido[1,2-a]benzimidazoles

2020 ◽  
Vol 73 (12) ◽  
pp. 1208
Author(s):  
Satyanarayana Gadde ◽  
Yun Cheuk Leung ◽  
Mohan Bhadbade ◽  
Belamy B. Cheung ◽  
David StC. Black ◽  
...  
Keyword(s):  
Nucleophilic Substitution ◽  
Suzuki Coupling ◽  
Solvent Free ◽  
Side Product ◽  
Sterically Demanding ◽  
Electron Donating Groups ◽  
Coupling Type

The reactivity and synthesis of new analogues of pyrido[1,2-a]benzimidazoles have been explored. Twenty-three derivatives bearing phenoxy, thiophenoxy, aniline, and aryl groups at the 1-position were successfully synthesised in 25–91% yield, via nucleophilic substitution, Buchwald–Hartwig amination, and Suzuki coupling type processes. Solvent free synthetic protocols were employed to achieve the nucleophilic substitution of anilines with electron donating groups or moderately electron withdrawing groups on a sterically demanding intermediate (7a). An unusual polycyclic heterocycle was identified as a side-product during this work: a dimeric bis(pyrido[1,2-a]benzimidazole).

Yttrium dialkyl supported by a silaamidinate ligand: synthesis, structure and catalysis on cyclotrimerization of isocyanates

2019 ◽  
Vol 55 (82) ◽  
pp. 12324-12327
Author(s):  
Deshuai Liu ◽  
Dahai Zhou ◽  
Hao Yang ◽  
Jianfeng Li ◽  
Chunming Cui
Keyword(s):  
High Activity ◽  
Functional Group ◽  
Sterically Demanding ◽  
Ligand Synthesis

A four-coordinate yttrium dialkyl complex with a sterically demanding silaamidinate ligand exhibited high activity and excellent functional group tolerance for the catalysis of isocyanate cyclotrimerization.

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