Evidence for a Cyclic Mechanism in (.eta.3-Allyl)palladium Chemistry. Promotion of .beta.-Hydride Elimination by Unsaturated Organometallics

1994 ◽  
Vol 116 (24) ◽  
pp. 11151-11152 ◽  
Author(s):  
Ehud Keinan ◽  
Sandeep Kumar ◽  
Vered Dangur ◽  
Jacob Vaya
Keyword(s):  
Cyclic Mechanism ◽  
Palladium Chemistry ◽  
Beta Hydride Elimination ◽  
Hydride Elimination

Controlled beta-hydride elimination during tetrahydropyran formation with Pd(II); diastereoselective formation of the tetrahydropyran ring of tetronomycin

1989 ◽  
Vol 30 (37) ◽  
pp. 4925-4928 ◽  
Author(s):  
M.F Semmelhack ◽  
Chung Ryeol Kim ◽  
Walter Dobler ◽  
Michael Meier
Keyword(s):  
Beta Hydride Elimination ◽  
Hydride Elimination

.beta.-Hydride elimination from methoxo vs. ethyl ligands: thermolysis of (DPPE)Pt(OCH3)2, (DPPE)Pt(CH2CH3)(OCH3) and (DPPE)Pt(CH2CH3)2

1986 ◽  
Vol 108 (16) ◽  
pp. 4805-4813 ◽  
Author(s):  
Henry E. Bryndza ◽  
Joseph C. Calabrese ◽  
Marianne. Marsi ◽  
D. Christopher. Roe ◽  
Wilson. Tam ◽  
...  
Keyword(s):  
Beta Hydride Elimination ◽  
Hydride Elimination

Alkyl iodide decomposition on copper surfaces: .alpha.-elimination and .beta.-hydride elimination from adsorbed alkyls

1991 ◽  
Vol 113 (16) ◽  
pp. 6308-6309 ◽  
Author(s):  
Cynthia J. Jenks ◽  
Chao Ming Chiang ◽  
Brian E. Bent
Keyword(s):  
Alkyl Iodide ◽  
Copper Surfaces ◽  
Beta Hydride Elimination ◽  
Hydride Elimination

Competitive uncatalyzed geometrical isomerization and .beta.-hydride elimination of alkyl complexes of platinum(II)

1989 ◽  
Vol 28 (2) ◽  
pp. 342-347 ◽  
Author(s):  
Giuseppe Alibrandi ◽  
Matteo Cusumano ◽  
Domenico Minniti ◽  
Luigi Monsu Scolaro ◽  
Raffaello Romeo
Keyword(s):  
Geometrical Isomerization ◽  
Alkyl Complexes ◽  
Beta Hydride Elimination ◽  
Hydride Elimination

scholarly journals Strain in Silica-Supported Ga (III) Sites: Neither Too Much nor Too Little for Propane Dehydrogenation Catalytic Activity

2020 ◽  
Author(s):  
C. S. Praveen ◽  
A. P. Borosy ◽  
Christophe Copéret ◽  
Aleix Comas Vives
Keyword(s):  
Catalytic Activity ◽  
Propane Dehydrogenation ◽  
Intrinsic Activity ◽  
Dehydrogenation Reaction ◽  
The Road ◽  
Highly Active ◽  
Beta Hydride Elimination ◽  
Hydride Elimination ◽  
Single Site Catalysts ◽  
Highly Strained

<p>Well-defined Ga(III) sites on SiO<sub>2</sub> are highly active, selective, and stable catalysts in the propane dehydrogenation reaction. In this contribution, we evaluate the catalytic activity towards propane dehydrogenation of tri-coordinated and tetra-coordinated Ga(III) sites on SiO<sub>2</sub> by means of first principles calculations using realistic amorphous periodic SiO<sub>2</sub>models. We evaluated the three reaction steps in propane dehydrogenation, namely the C-H activation of propane to form propyl, the beta-hydride elimination transfer to form propene, and a Ga-hydride, and the H-H coupling to release H<sub>2</sub>, regenerating the initial Ga-O bond and closing the catalytic cycle. Our work shows how Brønsted-Evans-Polanyi relationships are followed for these three reaction steps on Ga(III) sites on SiO<sub>2</sub> and highlights the role of the strain of the reactive Ga-O pairs on such sites of realistic amorphous SiO<sub>2</sub> models. While highly strained sites are very reactive sites for the initial C-H activation, they are more difficult to regenerate. The corresponding less strained sites are not reactive enough, pointing to the need of a right balance in strain to be an effective site for propane dehydrogenation. Overall, our work provides an understanding of the intrinsic activity of acidic Ga single sites towards the propane dehydrogenation reaction and paves the road towards the design and prediction of better single-site catalysts on SiO<sub>2 </sub>for the propane dehydrogenation reaction.</p>

Tertiary Alkylative Suzuki-Miyaura couplings

Synthesis ◽  
2022 ◽  
Author(s):  
Takashi Nishikata ◽  
Tom Sheppard ◽  
Naoki Tsuchiya
Keyword(s):  
Oxidative Addition ◽  
Short Review ◽  
The Other ◽  
Side Reactions ◽  
Coupling Reactions ◽  
Other Hand ◽  
Alkyl Electrophiles ◽  
Carbon Bonds ◽  
Beta Hydride Elimination ◽  
Hydride Elimination

The Suzuki-Miyaura coupling is extremely useful to construct Csp2-Csp2 carbon bonds. On the other hand, Csp2-Csp3 coupling reactions are do not work well, and tert-alkylative Suzuki-Miyaura coupling is particularly challenging due to problematic oxidative addition and beta-hydride elimination side reactions. In this short review, we will introduce recent examples of tert-alkylative Suzuki-Miyaura couplings with tert-alkyl electrophiles or -boron reagents. The review will mainly focus on catalyst and product structures and the proposed mechanisms .

Mechanism of .beta.-hydride elimination in adsorbed alkoxides

1993 ◽  
Vol 115 (2) ◽  
pp. 714-722 ◽  
Author(s):  
Andrew J. Gellman ◽  
Qing Dai
Keyword(s):  
Beta Hydride Elimination ◽  
Hydride Elimination
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