Palladium(II)-Catalyzed Cycloisomerization of Substituted 1,5-Hexadienes: A Combined Experimental and Computational Study on an Open and an Interrupted Hydropalladation/Carbopalladation/β-Hydride Elimination (HCHe) Catalytic Cycle

2012 ◽  
Vol 77 (11) ◽  
pp. 4980-4995 ◽  
Author(s):  
Björn Nelson ◽  
Sonja Herres-Pawlis ◽  
Wolf Hiller ◽  
Hans Preut ◽  
Carsten Strohmann ◽  
...  
Keyword(s):  
Computational Study ◽  
Catalytic Cycle ◽  
Hydride Elimination

scholarly journals Computational study of productive and non-productive cycles in fluoroalkene metathesis

2015 ◽  
Vol 11 ◽  
pp. 2150-2157 ◽  
Author(s):  
Markéta Rybáčková ◽  
Jan Hošek ◽  
Ondřej Šimůnek ◽  
Viola Kolaříková ◽  
Jaroslav Kvíčala
Keyword(s):  
Computational Study ◽  
Catalytic Cycle ◽  
Dft Study ◽  
Cross Metathesis ◽  
High Preference ◽  
The Cross

A detailed DFT study of the mechanism of metathesis of fluoroethene, 1-fluoroethene, 1,1-difluoroethene, cis- and trans-1,2-difluoroethene, tetrafluoroethene and chlorotrifluoroethene catalysed with the Hoveyda–Grubbs 2nd generation catalyst was performed. It revealed that a successful metathesis of hydrofluoroethenes is hampered by a high preference for a non-productive catalytic cycle proceeding through a ruthenacyclobutane intermediate bearing fluorines in positions 2 and 4. Moreover, the calculations showed that the cross-metathesis of perfluoro- or perhaloalkenes should be a feasible process and that the metathesis is not very sensitive to stereochemical issues.

scholarly journals Stereoretention in styrene heterodimerisation promoted by one-electron oxidants

2020 ◽  
Vol 11 (34) ◽  
pp. 9309-9324
Author(s):  
Xinglong Zhang ◽  
Robert S. Paton
Keyword(s):  
Computational Study ◽  
Catalytic Cycle

A computational study details the mechanism, catalytic cycle and origins of stereoselectivity underlying hole-catalyzed intermolecular alkene heterodimerisation to give unsymmetrical, tetra-substituted cyclobutanes.

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.

Four Oxidation States in a Single Photoredox Nickel‐Based Catalytic Cycle: A Computational Study

2019 ◽  
Vol 131 (12) ◽  
pp. 3938-3942 ◽  
Author(s):  
Adiran de Aguirre ◽  
Ignacio Funes‐Ardoiz ◽  
Feliu Maseras
Keyword(s):  
Computational Study ◽  
Catalytic Cycle ◽  
Oxidation States

Gas-Phase Reactions of the Group 10 Organometallic Cations, [(phen)M(CH3)]+ with Acetone: Only Platinum Promotes a Catalytic Cycle via the Enolate [(phen)Pt(OC(CH2)CH3)]+

2019 ◽  
Vol 233 (6) ◽  
pp. 845-864 ◽  
Author(s):  
Kim Greis ◽  
Allan J. Canty ◽  
Richard A. J. O’Hair
Keyword(s):  
Acetic Acid ◽  
Gas Phase ◽  
Ion Trap ◽  
Catalytic Cycle ◽  
Acetate Complex ◽  
Ion Molecule Reactions ◽  
Group 10 ◽  
Beta Hydride Elimination ◽  
Hydride Elimination ◽  
Organometallic Cations

Abstract Electrospray ionisation of the ligated group 10 metal complexes [(phen)M(O2CCH3)2] (M = Ni, Pd, Pt) generates the cations [(phen)M(O2CCH3)]+, whose gas-phase chemistry was studied using multistage mass spectrometry experiments in an ion trap mass spectrometer with the combination of collision-induced dissociation (CID) and ion-molecule reactions (IMR). A new catalytic cycle has been discovered. In step 1, decarboxylation of [(phen)M(O2CCH3)]+ under CID conditions generates the organometallic cations [(phen)M(CH3)]+, which react with acetone to generate the [(phen)M(CH3)(OC(CH3)2)]+ adducts in competition with formation of the coordinated enolate for M = Pt (step 2). For M = Ni and Pd, the adducts regenerate [(phen)M(CH3)]+ upon CID. In the case of M = Pt, loss of methane is favored over loss of acetone and results in the formation of the enolate complex, [(phen)Pt(OC(CH2)CH3)]+. Upon further CID, both methane and CO loss can be observed resulting in the formation of the ketenyl and ethyl complexes [(phen)Pt(OCCH)]+ and [(phen)Pt(CH2CH3)]+ (step 3), respectively. In step 4, CID of [(phen)Pt(CH2CH3)]+ results in a beta-hydride elimination reaction to yield the hydride complex, [(phen)Pt(H)]+, which reacts with acetic acid to regenerate the acetate complex [(phen)Pt(O2CCH3)]+ and H2 in step 5. Thus, the catalytic cycle is formally closed, which corresponds to the decomposition of acetone and acetic acid into methane, CO, CO2, ethene and H2. All except the last step of the catalytic cycle are modelled using DFT calculations with optimizations of structures at the M06/SDD 6-31G(d) level of theory.

A computational study of the mechanism for water oxidation by (bpc)(bpy)RuIIOH2

2014 ◽  
Vol 43 (36) ◽  
pp. 13776-13782 ◽  
Author(s):  
Ying Wang ◽  
Mårten S. G. Ahlquist
Keyword(s):  
Carboxylic Acid ◽  
Water Oxidation ◽  
Computational Study ◽  
Catalytic Cycle ◽  
Mechanistic Study

A mechanistic study on the catalytic cycle water oxidation with 1 [(bpc)(bpy)RuIIOH2]+ (Hbpc = 2,2′-bipyridine-6-carboxylic acid, bpy = 2,2′-bipyridine) is described in this paper.

Alkene-alkyl interconversion: an experimental and computational study of the olefin insertion and β-hydride elimination processes

2018 ◽  
Vol 47 (19) ◽  
pp. 6808-6818 ◽  
Author(s):  
S. Azpeitia ◽  
U. Prieto ◽  
E. San Sebastián ◽  
A. Rodríguez-Diéguez ◽  
M. A. Garralda ◽  
...  
Keyword(s):  
Computational Study ◽  
Alkyl Complexes ◽  
Hydride Elimination

Six new silyl-thioether rhodium and iridium compounds have been used to study the transformation of alkene- into alkyl-complexes and vice versa.

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