scholarly journals Stereoselective cobalt-catalyzed halofluoroalkylation of alkynes

2018 ◽  
Vol 9 (7) ◽  
pp. 1795-1802 ◽  
Author(s):  
Guojiao Wu ◽  
Axel Jacobi von Wangelin
Keyword(s):  
Halogen Atom ◽  
Atom Transfer ◽  
Chain Mechanism ◽  
Atom Economy ◽  
Unsaturated Hydrocarbons ◽  
Radical Chain ◽  
Mild Conditions ◽  
Radical Chain Mechanism ◽  
Acetone Water ◽  
Rapid Generation

Stereoselective additions of functionalized reagents to unsaturated hydrocarbons are attractive due to the high atom economy, modularity and rapid generation of complexity. We report a stereoselective cobalt-catalyzed (E)-halofluoroalkylation of alkynes/alkenes that under mild conditions (2 mol% cat., 20 °C, acetone/water, 3 h). This reaction operates via a radical chain mechanism involving terminal halogen atom transfer which obviates the need for a stoichiometric sacrificial reductant.

Metal ion initiated halogenation reaction of N-haloamines

1970 ◽  
Vol 48 (4) ◽  
pp. 544-545 ◽  
Author(s):  
F. Minisci ◽  
G. P. Gardini ◽  
F. Bertini
Keyword(s):  
Free Radical ◽  
Radical Cation ◽  
Chlorine Atom ◽  
Metal Ion ◽  
Chain Mechanism ◽  
Radical Chain ◽  
Radical Chain Mechanism ◽  
Halogenation Reaction ◽  
Amino Radical Cation ◽  
Methyl Heptanoate

The metal ion catalyzed chlorination of 1-chlorobutane, 1-chlorohexane, methyl-pentanoate, and methyl-heptanoate by protonated N-chloroamines proceeds by a free radical chain mechanism and the chain carrying species was shown not to be a chlorine atom, but an amino radical cation.

Catalysis of hydrogen peroxide dceomposition by 2-electron oxidation and reduction

1959 ◽  
Vol 12 (2) ◽  
pp. 147 ◽  
Author(s):  
NK King ◽  
ME Winfield
Keyword(s):  
Hydrogen Peroxide ◽  
Free Radical ◽  
Radical Formation ◽  
Single Electron ◽  
Chain Mechanism ◽  
Radical Chain ◽  
Radical Chain Mechanism ◽  
Free Radical Formation ◽  
Decomposition Of H2o2

A thermodynamical argument is used to support the suggestion made elsewhere that the more common radical chain mechanism for catalysed decomposition of H2O2 need not predominate if the catalyst can readily undergo a reversible 2-electron oxidation. How complete the exclusion of free radical formation may be depends upon the redox characteristics of the catalyst and on whether its oxidation by two single-electron steps is readily reversible along the same path.

Insight into the free-radical chain mechanism of gold-catalyzed hydrocarbon oxidation reactions in the liquid phase

2007 ◽  
Vol 122 (3-4) ◽  
pp. 284-291 ◽  
Author(s):  
Pascal Lignier ◽  
Franck Morfin ◽  
Laurent Piccolo ◽  
Jean-Luc Rousset ◽  
Valérie Caps
Keyword(s):  
Free Radical ◽  
Liquid Phase ◽  
Hydrocarbon Oxidation ◽  
Chain Mechanism ◽  
Oxidation Reactions ◽  
Radical Chain ◽  
Radical Chain Mechanism ◽  
Insight Into

Oxidation of the [nido-6,9-C2B8H10]2- Anion - An Alternative Source of the 1,6- and 1,10-Dicarba-closo-decaboranes(10)

1999 ◽  
Vol 64 (6) ◽  
pp. 971-976 ◽  
Author(s):  
Bohumil Štíbr ◽  
Zbyněk Janoušek ◽  
Matthew Trammell ◽  
Bohumír Grüner ◽  
Zbyněk Plzák
Keyword(s):  
Chain Mechanism ◽  
Alternative Source ◽  
Radical Chain ◽  
Radical Chain Mechanism ◽  
Chloro Derivatives

The oxidation of the [nido-6,9-C2B8H10]2- (1) dianion with CuCl2, is supposed to proceed via an unstable closo-2,6-C2B8H10 (2) intermediate, which is then rearranged into closo-1,6-C2B8H10 (3) (yields 30-35%). The synthesis is accompanied by the formation of the isomeric closo-dicarbaboranes 1,10-C2B8H10 (4) and 1,2-C2B8H10 (5) and the whole procedure can be modified to isolate only isomer 4 (yield 35%). Side products from the synthesis consist of a complex and so far unseparable mixture, in which arachno-4,6-C2B7H13, chloro derivatives closo-C2B8H9Cl, and trimeric compounds of a closo-(C2B8H9)2-C2B8H8 formulation were detected by GLC/MS techniques. These findings point to the involvement of a radical-chain mechanism in the reaction.

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