scholarly journals Half-sandwich nickel(II) complexes bearing 1,3-di(cycloalkyl)imidazol-2-ylidene ligands

2015 ◽  
Vol 11 ◽  
pp. 2171-2178 ◽  
Author(s):  
Johnathon Yau ◽  
Kaarel E Hunt ◽  
Laura McDougall ◽  
Alan R Kennedy ◽  
David J Nelson
Keyword(s):  
Cross Coupling ◽  
Nickel Catalysts ◽  
Coupling Reactions ◽  
New Members ◽  
X Ray ◽  
Aryl Chlorides ◽  
X Ray Crystallography ◽  
Cross Coupling Reactions ◽  
Aryl Bromides ◽  
Half Sandwich

Two new nickel catalysts have been prepared using a convenient procedure where nickelocene, the NHC·HBF4 salts, and [Et4N]Cl were heated in THF using microwave irradiation. The resulting [NiCl(Cp)(NHC)] complexes are air- and moisture stable in the solid state, and represent two new members of this valuable and practical class of nickel catalysts. The new species were fully characterised using methods including NMR spectroscopy and X-ray crystallography. When tested in model Suzuki–Miyaura cross-coupling reactions, these complexes were found to be active for the cross-coupling of aryl bromides and aryl chlorides.

Ferrocenyl phosphine–oxazaphospholidine oxide ligands for the Suzuki–Miyaura coupling of hindered aryl bromides and chlorides

2009 ◽  
Vol 87 (1) ◽  
pp. 171-175 ◽  
Author(s):  
Daniele Vinci ◽  
Nelson Martins ◽  
Ourida Saidi ◽  
John Bacsa ◽  
Amadeu Brigas ◽  
...  
Keyword(s):  
Cross Coupling ◽  
Boronic Acids ◽  
Coupling Reactions ◽  
Aryl Chlorides ◽  
Cross Coupling Reactions ◽  
Aryl Bromides ◽  
Highly Effective

A series of ferrocenyl oxazaphospholidine phosphines that differ electronically and sterically were investigated as ligands for the Suzuki–Miyaura cross-coupling reactions. One of these compounds, 1, was shown to be highly effective in the coupling reactions of bulky aryl bromides with boronic acids when combined with Pd(OAc)2, while another, 2, was capable of coupling aryl chlorides with boronic acids. However, these ligands were less effective in asymmetric induction.Key words: Suzuki–Miyaura coupling, ferrocenyl phosphines, aryl bromides, aryl chlorides, palladium.

scholarly journals Preparation and Diels–Alder/cross coupling reactions of a 2-diethanolaminoboron-substituted 1,3-diene

2009 ◽  
Vol 5 ◽  
Author(s):  
Liqiong Wang ◽  
Cynthia S Day ◽  
Marcus W Wright ◽  
Mark E Welker
Keyword(s):  
Cross Coupling ◽  
Diels Alder ◽  
High Yield ◽  
Coupling Reactions ◽  
X Ray ◽  
X Ray Crystallography ◽  
Cross Coupling Reactions

A 2-diethanolamine boronyl substituted 1,3-diene has been synthesized in high yield and characterized spectroscopically as well as by X-ray crystallography. This diene has then subsequently been used in a number of fast, high yielding Diels–Alder/cross coupling reactions.

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 Microwave-Enhanced Cross-Coupling Reactions Involving Alkynyltrifluoroborates with Aryl Bromides

Molecules ◽  
2013 ◽  
Vol 18 (2) ◽  
pp. 1755-1761 ◽  
Author(s):  
Vitali Coltuclu ◽  
Eric Dadush ◽  
Abhijit Naravane ◽  
George Kabalka
Keyword(s):  
Cross Coupling ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Aryl Bromides

scholarly journals Protecting group-free, selective cross-coupling of alkyltrifluoroborates with borylated aryl bromides via photoredox/nickel dual catalysis

2015 ◽  
Vol 112 (39) ◽  
pp. 12026-12029 ◽  
Author(s):  
Yohei Yamashita ◽  
John C. Tellis ◽  
Gary A. Molander
Keyword(s):  
Small Molecules ◽  
Functional Group ◽  
Cross Coupling ◽  
Differential Protection ◽  
Coupling Reactions ◽  
Protecting Group ◽  
Cross Coupling Reactions ◽  
Aryl Bromides ◽  
Rapid Construction ◽  
Metal Catalyzed

Orthogonal reactivity modes offer substantial opportunities for rapid construction of complex small molecules. However, most strategies for imparting orthogonality to cross-coupling reactions rely on differential protection of reactive sites, greatly reducing both atom and step economies. Reported here is a strategy for orthogonal cross-coupling wherein a mechanistically distinct activation mode for transmetalation of sp3-hybridized organoboron reagents enables C-C bond formation in the presence of various protected and unprotected sp2-hybridized organoborons. This manifold has the potential for broad application, because orthogonality is inherent to the activation mode itself. The diversification potential of this platform is shown in the rapid elaboration of a trifunctional lynchpin through various transition metal-catalyzed processes without nonproductive deprotection or functional group manipulation steps.

scholarly journals Preparation of pyridine-3,4-diols, their crystal packing and their use as precursors for palladium-catalyzed cross-coupling reactions

2010 ◽  
Vol 6 ◽  
Author(s):  
Tilman Lechel ◽  
Irene Brüdgam ◽  
Hans-Ulrich Reissig
Keyword(s):  
Crystal Structure ◽  
Crystal Packing ◽  
Cross Coupling ◽  
Crystal Structure Analysis ◽  
Coupling Reactions ◽  
X Ray ◽  
Cross Coupling Reactions ◽  
Fluorescence Measurements ◽  
Subsequent Conversion ◽  
Palladium Catalyzed

A series of trifluoromethyl-substituted 3-alkoxypyridinol derivatives has been deprotected to furnish pyridine-3,4-diol derivatives in good yields. The X-ray crystal structure analysis proved that a 1:1 mixture of pyridine-3,4-diols and their pyridin-4-one tautomers exist in the solid state. Subsequent conversion into bis(perfluoroalkanesulfonate)s were smoothly achieved. The obtained compounds were used as substrates for palladium-catalyzed coupling reactions. Fluorescence measurements of the biscoupled products showed a maximum of emission in the violet region of the spectrum.

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