scholarly journals Alkene-oxo and alkene-alkene coupling on Pt(II)

2005 ◽  
Author(s):  
◽  
Endre Szuromi
Keyword(s):  
Exchange Reaction ◽  
Bond Cleavage ◽  
Kinetic Studies ◽  
Direct Reaction ◽  
Triflic Acid ◽  
Common Features ◽  
Allyl Complex ◽  
Significant Discovery

Tetranuclear Pt(II) oxo-complex [(COD)4Pt4([mu]3-O)2Cl2](BF4)2 (1) (COD = 1,5- cyclooctadiene) was found to readily react with a variety of alkenes (ethylene, norbornene, propylene and cyclopentene). The most significant discovery resulted from the norbornene reaction, which gave platinaoxetane [(COD)2Pt2(OC7H10)Cl]BF4 (4), the first metallaoxetane obtained from the direct reaction of an oxo complex and an alkene. A facile alkene-exchange reaction was observed between platinaoxetane 4 and norbornene-derivative 5 giving a new platinaoxetane and free norbornene. Kinetic studies revealed that the reaction is catalyzed by possibly more than one electrophilic catalyst.We describe two probable mechanisms for the reaction.Cationic Pt(II) complexes (COD)Pt(OTf)2 and [(COD)Pt(THF)(OTf)]OTf were found to readily react with alkenes such as norbornenes, cyclopentene, propylene and ethylene.Two common features of these reactions were alkene C-H bond cleavage and triflic acid elimination. Norbornenes, cyclopentene and ethylene gave alkene-coupled products, while propylene resulted in a simple allyl complex.

Exploring the acid-catalyzed substitution mechanism of [Fe4S4Cl4]2−

2016 ◽  
Vol 45 (1) ◽  
pp. 307-314 ◽  
Author(s):  
Thaer M. M. Al-Rammahi ◽  
Richard A. Henderson
Keyword(s):  
Bond Cleavage ◽  
Kinetic Studies ◽  
Substitution Reactions ◽  
Substitution Mechanism ◽  
Acid Catalyzed

Kinetic studies focussing on either the protonation or substitution step of the acid catalyzed substitution reactions of [Fe4S4Cl4]2− support a mechanism involving concomitant cluster protonation and Fe–(μ3-SH) bond cleavage.

scholarly journals Analyzing Mechanisms in Co(I) Redox Catalysis Using a Pattern Recognition Platform

2020 ◽  
Author(s):  
Tianhua Tang ◽  
Christopher Sandford ◽  
Shelley D. Minteer ◽  
Matthew Sigman
Keyword(s):  
Pattern Recognition ◽  
Bond Cleavage ◽  
Linear Regression Analysis ◽  
Benzyl Bromide ◽  
Kinetic Studies ◽  
Outer Sphere ◽  
Redox Catalysis ◽  
Tridentate Ligands ◽  
Electron Transfer Mechanism ◽  
Multivariable Linear Regression Analysis

Redox catalysis has been broadly utilized in electrochemical synthesis due to its kinetic advantages over direct electrolysis. The appropriate choice of redox mediator can avoid electrode passivation and overpotential, which strongly inhibit the efficient activation of substrates in electrolysis. Despite the benefits brought by redox catalysis, establishing the precise nature of substrate activation remains challenging. Herein, we determine that a Co(I) complex bearing two <i>N</i>,<i>N</i>,<i>N</i>-tridentate ligands acts as a competent redox catalyst for the reduction of benzyl bromide substrates. Kinetic studies combining electroanalytical techniques with multivariable linear-regression analysis were conducted, disclosing an outer-sphere electron-transfer mechanism, which occurs in concert with C–Br bond cleavage. Furthermore, we apply a pattern recognition platform to distinguish between mechanisms in the activation of benzyl bromides, found to be dependent on the ligation state of the cobalt(I) center and ligand used.

Stoichiometric CH Bond Cleavage Reaction in a Bis(carboxylato)ruthenium(II) Complex and Its Application to the Catalytic H-D Exchange Reaction of Carboxylic Acids

ChemCatChem ◽  
2013 ◽  
Vol 5 (5) ◽  
pp. 1101-1115 ◽  
Author(s):  
Masafumi Hirano ◽  
Ryo Fujimoto ◽  
Kohei Hatagami ◽  
Nobuyuki Komine ◽  
Sanshiro Komiya
Keyword(s):  
Exchange Reaction ◽  
Carboxylic Acids ◽  
Bond Cleavage ◽  
Cleavage Reaction ◽  
Bond Cleavage Reaction
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