Divergent Carbonylation Reactivity Preferences of Nickel Complexes Containing Amido Pincer Ligands: Migratory Insertion versus Reductive Elimination

2011 ◽  
Vol 31 (2) ◽  
pp. 700-708 ◽  
Author(s):  
Lan-Chang Liang ◽  
Yu-Ting Hung ◽  
Yu-Lun Huang ◽  
Pin-Shu Chien ◽  
Pei-Ying Lee ◽  
...  
Keyword(s):  
Nickel Complexes ◽  
Reductive Elimination ◽  
Pincer Ligands ◽  
Migratory Insertion

scholarly journals autodE: Automated Calculation of Reaction Energy Profiles – Application to Organic and Organometallic Reactions

2020 ◽  
Author(s):  
Tom Young ◽  
Joseph Silcock ◽  
Alistair Sterling ◽  
Fernanda Duarte
Keyword(s):  
Claisen Rearrangement ◽  
Reductive Elimination ◽  
Conformational Sampling ◽  
Reaction Energy ◽  
General Applicability ◽  
Organometallic Reactions ◽  
Energy Profiles ◽  
Migratory Insertion ◽  
Human Effort ◽  
Metal Catalyzed

Calculating reaction profiles to aid in mechanistic elucidation has long been the domain of the expert computational chemist. We introduce autodE, an open-source tool capable of locating transition states and minima and delivering a full reaction energy profile with minimal human effort (https://github.com/duartegroup/autodE). autodE is broadly applicable to study organic and organometallic reaction classes, including addition, substitution, elimination, migratory insertion, oxidative addition and reductive elimination; it accounts for conformational sampling of both minima and TSs, and is compatible with many electronic structure packages. The general applicability of autodE is demonstrated in complex multi-step reactions, including metal-catalyzed cobalt- and rhodium-catalyzed hydroformylation, and an Ireland-Claisen rearrangement.

Access to Substituted Indenol Ethers via a Regioselective Intermolecular Carbopalladation Cascade

2019 ◽  
Author(s):  
Brandon L. Coles-Taylor ◽  
Maximilian S. McCallum ◽  
Andrés G. Muñoz ◽  
Brian Michel
Keyword(s):  
Heck Reaction ◽  
Reductive Elimination ◽  
Catalytic Cycle ◽  
Reaction Conditions ◽  
Powerful Approach ◽  
Migratory Insertion ◽  
Ynol Ethers ◽  
Hydride Elimination ◽  
Turn Over

Alkyne carbopalladation reactions represent a powerful approach to generating multiple new C–C bonds and substituted alkenes, however regioselectivity is often challenging for intermolecular variants. By utilizing ynol ethers as polarized alkynes we observe complete regiocontrol of migratory insertion with Pd–Ar species. A Heck reaction was used to turn-over the catalytic cycle by intercepting the vinyl-Pd adduct of carbopalladation with a pendant alkene. When using <i>o</i>-iodo styrenes substrates the resulting products are oligosubstituted 1-indenol ethers with defined stereochemistry based on the initial alkene geometry. By blocking β-hydride elimination we demonstrated C–H and C–C reductive elimination steps for catalyst turnover. Herein we report the optimization of reaction conditions, scope, and alternative termination steps.

scholarly journals Synthesis, Solid-state Structures, Solution Behaviour and Catalysis Studies of Nickel Complexes of Bis(benzimidazolin-2-ylidene)pyridine Pincer Ligands

2012 ◽  
Vol 65 (7) ◽  
pp. 823 ◽  
Author(s):  
Karen D. M. MaGee ◽  
Guy Travers ◽  
Brian W. Skelton ◽  
Massimilliano Massi ◽  
Alan D. Payne ◽  
...  
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Nickel Complexes ◽  
Pincer Ligands ◽  
X Ray Diffraction ◽  
Nmr Studies ◽  
X Ray ◽  
Solution Studies ◽  
Solid State Structures ◽  
Solution Behaviour

N-Heterocyclic carbene–nickel complexes with five- and four-coordinate geometries [(CNC)NiBr2] and [(CNC)NiBr]X (X = PF6 or BPh4) have been prepared with the pincer ligands 2,6-bis(N-octylbenzimidazolin-2-ylidene)pyridine and 2,6-bis(N-butyl-5,6-dimethoxybenzimidazolin-2-ylidene)pyridine. The addition of the n-octyl substituent significantly extends the solubility of the complexes and has allowed UV-vis solution studies of the complexes in dichloromethane and methanol. The four- and five-coordinate species exist in equilibrium in solution and this equilibrium has been explored by UV-vis studies. The complexes have also been characterized by NMR studies, and single crystal X-ray diffraction studies have been performed on [(CNC)NiBr2] (where CNC = 2,6-bis(N-octylbenzimidazolin-2-ylidene)pyridine) and [(CNC)NiBr]BPh4 (where CNC = 2,6-bis(N-butyl-5,6-dimethoxybenzimidazolin-2-ylidene)pyridine).

Palladium-Catalyzed Annulation via Acyl C–H Bond Activation

Synlett ◽  
2018 ◽  
Vol 29 (16) ◽  
pp. 2087-2092 ◽  
Author(s):  
Gui Chen ◽  
Xueliang Huang ◽  
Yinghua Yu
Keyword(s):  
Bond Activation ◽  
Reductive Elimination ◽  
Straightforward Manner ◽  
Migratory Insertion ◽  
Palladium Catalyzed

Palladium-catalyzed annulation of ortho-bromobenzaldehydes with aryl diazoesters is achieved via a sequence of palladium carbene migratory insertion, acyl C–H bond activation and reductive elimination of a seven-membered palladacyclic intermediate. A variety of isocoumarin derivatives were furnished in a straightforward manner.

PREPARATION OF ACYL(p-CYANOPHENOXO)(2,2′-BIPYRIDINE)NICKEL AND REDUCTIVE ELIMINATION OF PHENYL ESTERS FROM ACYL(PHENOXO)NICKEL COMPLEXES

1979 ◽  
Vol 8 (12) ◽  
pp. 1513-1516 ◽  
Author(s):  
Teiji Kohara ◽  
Sanshiro Komiya ◽  
Takakazu Yamamoto ◽  
Akio Yamamoto
Keyword(s):  
Nickel Complexes ◽  
Reductive Elimination

scholarly journals autodE: Automated Calculation of Reaction Energy Profiles – Application to Organic and Organometallic Reactions

2020 ◽  
Author(s):  
Tom Young ◽  
Joseph Silcock ◽  
Alistair Sterling ◽  
Fernanda Duarte
Keyword(s):  
Claisen Rearrangement ◽  
Reductive Elimination ◽  
Conformational Sampling ◽  
Reaction Energy ◽  
General Applicability ◽  
Organometallic Reactions ◽  
Energy Profiles ◽  
Migratory Insertion ◽  
Human Effort ◽  
Metal Catalyzed

Calculating reaction profiles to aid in mechanistic elucidation has long been the domain of the expert computational chemist. We introduce autodE, an open-source tool capable of locating transition states and minima and delivering a full reaction energy profile with minimal human effort (https://github.com/duartegroup/autodE). autodE is broadly applicable to study organic and organometallic reaction classes, including addition, substitution, elimination, migratory insertion, oxidative addition and reductive elimination; it accounts for conformational sampling of both minima and TSs, and is compatible with many electronic structure packages. The general applicability of autodE is demonstrated in complex multi-step reactions, including metal-catalyzed cobalt- and rhodium-catalyzed hydroformylation, and an Ireland-Claisen rearrangement.

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