Stabilization of Nickel Complexes with Ni0···H–N Bonding Interactions Using Sterically Demanding Cyclic Diphosphine Ligands

2011 ◽  
Vol 31 (1) ◽  
pp. 144-156 ◽  
Author(s):  
Eric S. Wiedner ◽  
Jenny Y. Yang ◽  
Shentan Chen ◽  
Simone Raugei ◽  
William G. Dougherty ◽  
...  
Keyword(s):  
Nickel Complexes ◽  
Diphosphine Ligands ◽  
Sterically Demanding

Comparison of Cobalt and Nickel Complexes with Sterically Demanding Cyclic Diphosphine Ligands: Electrocatalytic H2Production by [Co(PtBu2NPh2)(CH3CN)3](BF4)2†

2010 ◽  
Vol 29 (21) ◽  
pp. 5390-5401 ◽  
Author(s):  
Eric S. Wiedner ◽  
Jenny Y. Yang ◽  
William G. Dougherty ◽  
W. Scott Kassel ◽  
R. Morris Bullock ◽  
...  
Keyword(s):  
Nickel Complexes ◽  
Diphosphine Ligands ◽  
Sterically Demanding ◽  
Cobalt And Nickel

Monomeric nickel hydroxide stabilized by a sterically demanding phosphorus–nitrogen PN3P-pincer ligand: synthesis, reactivity and catalysis

2018 ◽  
Vol 47 (45) ◽  
pp. 16057-16065 ◽  
Author(s):  
Changguang Yao ◽  
Priyanka Chakraborty ◽  
Emanuele Aresu ◽  
Huaifeng Li ◽  
Chao Guan ◽  
...  
Keyword(s):  
Nickel Hydroxide ◽  
Nickel Complexes ◽  
Pincer Ligand ◽  
Sterically Demanding ◽  
Ligand Synthesis

Various new nickel complexes and amides are synthesized using monomeric nickel hydroxide (PN3P)Ni(OH) (3) as the precursor or catalyst.

Spatiotemporal Control of Amide Radicals During Photocatalysis

2020 ◽  
Author(s):  
Shogo Mori ◽  
Takahiro Aoki ◽  
Kaliyamoorthy Selvam ◽  
Shunichi Fukuzumi ◽  
Jieun Jung ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Nickel Complex ◽  
Nickel Complexes ◽  
Semiconductor Material ◽  
Radical Reactions ◽  
Substitution Reactions ◽  
Carbon Neutrality ◽  
Spatiotemporal Control ◽  
Scalable Production ◽  
Salt Waste

Despite the continuing popularity of radical reactions in organic synthesis, much remains to be explored in this area. Herein, we describe how spatiotemporal control can be exerted over the formation and reactivity of divergent exchangeable formamide radicals using nickel complexes with a semiconductor material (TiO<sub>2</sub>) under irradiation from near-UV–Vis light. Depending on the bipyridine ligand used and the quantity of the nickel complex that is hybridized on or nonhydridized over the TiO<sub>2</sub> surface, these radicals selectively undergo substitution reactions at the carbon center of carbon–bromine bonds that proceed via three different pathways. As the scalable production of formamides from CO<sub>2</sub> does not produce salt waste, these methods could add a new dimension to the search for carbon neutrality through the indirect incorporation of CO<sub>2</sub> into organic frameworks.

Regioselective Gas-Phase n-Butane Transfer Dehydrogenation via Silica-Supported Pincer-Iridium Complexes

2020 ◽  
Author(s):  
Boris Sheludko ◽  
Cristina Castro ◽  
Chaitanya Khalap ◽  
Thomas Emge ◽  
Alan Goldman ◽  
...  
Keyword(s):  
Gas Phase ◽  
Active Site ◽  
Lower Cost ◽  
Open Systems ◽  
Iridium Complexes ◽  
Terminal Olefin ◽  
Molecular Precursors ◽  
Sterically Demanding ◽  
Olefin Production ◽  
Steam Cracking

<b>Abstract:</b> The production of olefins via on-purpose dehydrogenation of alkanes allows for a more efficient, selective and lower cost alternative to processes such as steam cracking. Silica-supported pincer-iridium complexes of the form [(≡SiO-<sup>R4</sup>POCOP)Ir(CO)] (<sup>R4</sup>POCOP = κ<sup>3</sup>-C<sub>6</sub>H<sub>3</sub>-2,6-(OPR<sub>2</sub>)<sub>2</sub>) are effective for acceptorless alkane dehydrogenation, and have been shown stable up to 300 °C. However, while solution-phase analogues of such species have demonstrated high regioselectivity for terminal olefin production under transfer dehydrogenation conditions at or below 240 °C, in open systems at 300 °C, regioselectivity under acceptorless dehydrogenation conditions is consistently low. In this work, complexes <a>[(≡SiO-<i><sup>t</sup></i><sup>Bu4</sup>POCOP)Ir(CO)] </a>(<b>1</b>) and [(≡SiO-<i><sup>i</sup></i><sup>Pr4</sup>PCP)Ir(CO)] (<b>2</b>) were synthesized via immobilization of molecular precursors. These complexes were used for gas-phase butane transfer dehydrogenation using increasingly sterically demanding olefins, resulting in observed selectivities of up to 77%. The results indicate that the active site is conserved upon immobilization.

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.

Thermally Stable Half-Sandwich Benzhydryl Ln(II) (Ln = Sm, Yb) Complexes Supported by Sterically Demanding Carbazolyl and Fluorenyl Ligands

2019 ◽  
Vol 38 (24) ◽  
pp. 4615-4624 ◽  
Author(s):  
Alexander N. Selikhov ◽  
Andrey S. Shavyrin ◽  
Anton V. Cherkasov ◽  
Georgy K. Fukin ◽  
Alexander A. Trifonov
Keyword(s):  
Thermally Stable ◽  
Sterically Demanding ◽  
Half Sandwich

Synthesis of unsaturated amines from butadiene and allylamines in presence of palladium and nickel complexes

1978 ◽  
Vol 27 (6) ◽  
pp. 1230-1232 ◽  
Author(s):  
U. M. Dzhemilev ◽  
F. A. Selimov ◽  
A. Z. Yakupova ◽  
G. A. Tolstikov
Keyword(s):  
Nickel Complexes
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