Electron transfer and bond breaking. Examples of passage from a sequential to a concerted mechanism in the electrochemical reductive cleavage of arylmethyl halides

1992 ◽  
Vol 114 (17) ◽  
pp. 6892-6904 ◽  
Author(s):  
Claude P. Andrieux ◽  
Annie Le Gorande ◽  
Jean Michel Saveant
Keyword(s):  
Electron Transfer ◽  
Reductive Cleavage ◽  
Bond Breaking ◽  
Concerted Mechanism

Reductive cleavage of carbon–chlorine bonds at catalytic and non-catalytic electrodes in 1-butyl-3-methylimidazolium tetrafluoroborate

2015 ◽  
Vol 17 (46) ◽  
pp. 31228-31236 ◽  
Author(s):  
Abdirisak A. Isse ◽  
Ludovico Scarpa ◽  
Christian Durante ◽  
Armando Gennaro
Keyword(s):  
Electron Transfer ◽  
Electrocatalytic Activity ◽  
Reductive Cleavage ◽  
Dissociative Electron Transfer ◽  
Concerted Mechanism ◽  
Good Electrocatalytic Activity

Silver shows good electrocatalytic activity for the reduction of organic chlorides only when the dissociative electron transfer follows a concerted mechanism.

scholarly journals Hypervalent Iodine-Mediated Styrene Hetero- and Homodimerization Initiation Proceeds with Two-Electron Reductive Cleavage

2020 ◽  
Author(s):  
Aqeel A. Hussein ◽  
Yumiao Ma ◽  
Ahmed Al-Yasari
Keyword(s):  
Electron Transfer ◽  
Density Functional ◽  
Reductive Cleavage ◽  
Hypervalent Iodine ◽  
Functional Theory ◽  
Concerted Mechanism ◽  
Bonding Interaction ◽  
Reaction Proceeds ◽  
Dynamics Simulations ◽  
Insight Into

<p><a>A mechanistic insight into </a>the hetero- and homodimerizations (HETD and HOMD) of styrenes promoted by hypervalent iodine reagents (HVIRs; <b>DMP</b> and <b>PIDA</b>) and facilitated by HFIP to yield all <i>trans</i> cyclobutanes is reported using density functional theory (DFT) calculations. The initialization involving direct bimolecular one-electron transfer is found to be highly unfavored, especially for the <b>PIDA</b> system. At this point, we suggest that the reaction is initiated with an overall two-electron reductive cleavage of two I─O bond cleavages, affording I(III) (iodinane) and I(I) (iodobenzene) product with DMP and PIDA as oxidant, respectively. The resulting acetate groups are stabilized by the solvent HFIP through strong hydrogen bonding interaction, which promotes the electron transfer process. The nature of the electron transfer is studied in detail and found that the overall two-electron transfer occurs within tri-molecular complex organized by π-stacking interactions and as a stepwise and concerted mechanism for I(III) and I(V) oxidants, respectively. The reaction rate is determined by the initialization step: for I(III), the initiation is thermodynamically endergonic, whereas the endergonicity for I(V) is modest. Upon initialization, the reaction proceeds through a stepwise [2+2] pathway, involving a radical-cationic π-π stacked intermediate, either hetero- or homodimerized. DFT results supported by quasiclassical molecular dynamics simulations show that HOMD is dynamically competing pathway to HETD although the latter is relatively faster, in accordance with experimental observations. </p>

scholarly journals Hypervalent Iodine-Mediated Styrene Hetero- and Homodimerization Initiation Proceeds with Two-Electron Reductive Cleavage

2020 ◽  
Author(s):  
Aqeel A. Hussein ◽  
Yumiao Ma ◽  
Ahmed Al-Yasari
Keyword(s):  
Electron Transfer ◽  
Density Functional ◽  
Reductive Cleavage ◽  
Hypervalent Iodine ◽  
Functional Theory ◽  
Concerted Mechanism ◽  
Bonding Interaction ◽  
Reaction Proceeds ◽  
Dynamics Simulations ◽  
Insight Into

<p><a>A mechanistic insight into </a>the hetero- and homodimerizations (HETD and HOMD) of styrenes promoted by hypervalent iodine reagents (HVIRs; <b>DMP</b> and <b>PIDA</b>) and facilitated by HFIP to yield all <i>trans</i> cyclobutanes is reported using density functional theory (DFT) calculations. The initialization involving direct bimolecular one-electron transfer is found to be highly unfavored, especially for the <b>PIDA</b> system. At this point, we suggest that the reaction is initiated with an overall two-electron reductive cleavage of two I─O bond cleavages, affording I(III) (iodinane) and I(I) (iodobenzene) product with DMP and PIDA as oxidant, respectively. The resulting acetate groups are stabilized by the solvent HFIP through strong hydrogen bonding interaction, which promotes the electron transfer process. The nature of the electron transfer is studied in detail and found that the overall two-electron transfer occurs within tri-molecular complex organized by π-stacking interactions and as a stepwise and concerted mechanism for I(III) and I(V) oxidants, respectively. The reaction rate is determined by the initialization step: for I(III), the initiation is thermodynamically endergonic, whereas the endergonicity for I(V) is modest. Upon initialization, the reaction proceeds through a stepwise [2+2] pathway, involving a radical-cationic π-π stacked intermediate, either hetero- or homodimerized. DFT results supported by quasiclassical molecular dynamics simulations show that HOMD is dynamically competing pathway to HETD although the latter is relatively faster, in accordance with experimental observations. </p>

scholarly journals Hypervalent Iodine-Mediated Styrene Hetero- and Homodimerization Initiation Proceeds with Two-Electron Reductive Cleavage

2020 ◽  
Author(s):  
Aqeel A. Hussein ◽  
Yumiao Ma ◽  
Ahmed Al-Yasari
Keyword(s):  
Electron Transfer ◽  
Density Functional ◽  
Reductive Cleavage ◽  
Hypervalent Iodine ◽  
Functional Theory ◽  
Concerted Mechanism ◽  
Bonding Interaction ◽  
Reaction Proceeds ◽  
Dynamics Simulations ◽  
Insight Into

<p><a>A mechanistic insight into </a>the hetero- and homodimerizations (HETD and HOMD) of styrenes promoted by hypervalent iodine reagents (HVIRs; <b>DMP</b> and <b>PIDA</b>) and facilitated by HFIP to yield all <i>trans</i> cyclobutanes is reported using density functional theory (DFT) calculations. The initialization involving direct bimolecular one-electron transfer is found to be highly unfavored, especially for the <b>PIDA</b> system. At this point, we suggest that the reaction is initiated with an overall two-electron reductive cleavage of two I─O bond cleavages, affording I(III) (iodinane) and I(I) (iodobenzene) product with DMP and PIDA as oxidant, respectively. The resulting acetate groups are stabilized by the solvent HFIP through strong hydrogen bonding interaction, which promotes the electron transfer process. The nature of the electron transfer is studied in detail and found that the overall two-electron transfer occurs within tri-molecular complex organized by π-stacking interactions and as a stepwise and concerted mechanism for I(III) and I(V) oxidants, respectively. The reaction rate is determined by the initialization step: for I(III), the initiation is thermodynamically endergonic, whereas the endergonicity for I(V) is modest. Upon initialization, the reaction proceeds through a stepwise [2+2] pathway, involving a radical-cationic π-π stacked intermediate, either hetero- or homodimerized. DFT results supported by quasiclassical molecular dynamics simulations show that HOMD is dynamically competing pathway to HETD although the latter is relatively faster, in accordance with experimental observations. </p>

scholarly journals Metal-Free Reductive Cleavage of CN and SN Bonds by Photoactivated Electron Transfer from a Neutral Organic Donor

2013 ◽  
Vol 126 (2) ◽  
pp. 484-488 ◽  
Author(s):  
Steven O'Sullivan ◽  
Eswararao Doni ◽  
Tell Tuttle ◽  
John A. Murphy
Keyword(s):  
Electron Transfer ◽  
Reductive Cleavage ◽  
Metal Free

Stepwise and Concerted Pathways in Thermal and Photoinduced Electron-Transfer/Bond-Breaking Reactions

2000 ◽  
Vol 104 (32) ◽  
pp. 7492-7501 ◽  
Author(s):  
Cyrille Costentin ◽  
Marc Robert ◽  
Jean-Michel Savéant
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Bond Breaking

Elementary Reactions in the Condensed Phase: Bond Breaking, Isomerization and Electron Transfer

2003 ◽  
pp. 391-398
Author(s):  
Eva Åkesson ◽  
Alexander N. Tarnovsky ◽  
Gabor Benkö ◽  
Arkady Yartsev ◽  
Villy Sundström
Keyword(s):  
Electron Transfer ◽  
Condensed Phase ◽  
Bond Breaking ◽  
Elementary Reactions
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