Enantioselective Palladium-Catalyzed Decarboxylative Allylation of β-Keto Esters Assisted by a Thiourea

Enantioselective intramolecular decarboxylative allylation of β-keto esters catalyzed by a palladium bis(phosphine)-thiourea complex is reported. This procedure is not only effective for β-keto esters, but also effective for β-keto amides. An intermolecular variant of the asymmetric decarboxylative allylation is also established. DFT calculations indicate that an outer-sphere mechanism is viable for the decarboxylative allylation of β-keto esters.

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Palladium-catalyzed alkylation of unactivated olefins

Pure and Applied Chemistry ◽

10.1351/pac200476030671 ◽

2004 ◽

Vol 76 (3) ◽

pp. 671-678 ◽

Cited By ~ 14

Author(s):

Ross A. Widenhoefer

Keyword(s):

Good Yield ◽

Catalytic Amount ◽

Outer Sphere ◽

Deuterium Labeling ◽

Carbon Nucleophiles ◽

Keto Esters ◽

Reactive Carbon ◽

Aryl Ketones ◽

Palladium Catalyzed ◽

Hydride Elimination

The reaction of a 3-butenyl β-diketone with a catalytic amount of PdCl2(CH3CN)2 in dioxane at room temperature led to olefin hydroalkylation and formation of the corresponding 2-acylcyclohexanone in good yield as a single regioisomer. Deuterium-labeling experiments for the hydroalkylation of 7-octene-2,4-dione were in accord with a mechanism involving outer-sphere attack of the pendant enol on a palladium-complexed olefin to form a palladium cyclohexyl species, followed by palladium migration via iterative β-hydride elimination/addition and protonolysis from a palladium enolate complex. In comparison to a 3-butenyl β-diketone, reaction of a 4-pentenyl β-diketone with a catalytic amount of PdCl2(CH3CN)2 in the presence of CuCl2 led to oxidative alkylation and formation of the corresponding 2-acyl-3-methyl-2-cyclohexenone in good yield as a single isomer. Unactivated olefins tethered to less reactive carbon nucleophiles such as β-keto esters, α-aryl ketones, and even dialkyl ketones underwent palladium-catalyzed hydroalkylation in the presence of Me3SiCl or HCl to form the corresponding cyclohexanones in moderate-to-good yield with high regioselectivity.

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Kinetics and mechanism of redox reactions of U(III) ions with monochloroacetic and dichloroacetic acids

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19790401 ◽

1979 ◽

Vol 44 (2) ◽

pp. 401-405 ◽

Cited By ~ 2

Author(s):

Ľubica Adamčíková ◽

Ľudovít Treindl

Keyword(s):

Redox Reactions ◽

Reaction Rate ◽

Activation Parameters ◽

Outer Sphere ◽

Alcohol Concentration ◽

Kinetics And Mechanism ◽

Solvent Structure ◽

Influence Of Ph ◽

Sphere Mechanism

The kinetics and mechanism of the redox reactions of U3+ ions with mono- and dichloroacetic acids were studied. The influence of pH was observed mainly in the second case and led to the determination of the rate constants and activation parameters corresponding to two parallel steps, namely oxidation of U3+ with CHCl2COO- ions and oxidation of U3+ with CHCl2.COOH molecules. The influence of binary mixtures of water with methanol, ethanol, isopropanol, or tert-butenol on the reaction rate was followed. Increasing alcohol concentration influences the rate constant not only through changing dielectric constant and solvation of the reactants but also through a change of the solvent structure which plays a role in reactions with an outer sphere mechanism of the electron transfer.

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RuIII(edta) complexes as molecular redox catalysts in chemical and electrochemical reduction of dioxygen and hydrogen peroxide: inner-sphere versus outer-sphere mechanism

RSC Advances ◽

10.1039/d1ra03293c ◽

2021 ◽

Vol 11 (35) ◽

pp. 21359-21366

Author(s):

Debabrata Chatterjee ◽

Marta Chrzanowska ◽

Anna Katafias ◽

Maria Oszajca ◽

Rudi van Eldik

Keyword(s):

Hydrogen Peroxide ◽

Electron Transfer ◽

Electrochemical Reduction ◽

Molecular Oxygen ◽

Outer Sphere ◽

Transfer Processes ◽

Edta Complexes ◽

Inner Sphere ◽

Electron Transfer Processes ◽

Sphere Mechanism

[RuII(edta)(L)]2–, where edta4– =ethylenediaminetetraacetate; L = pyrazine (pz) and H2O, can reduce molecular oxygen sequentially to hydrogen peroxide and further to water by involving both outer-sphere and inner-sphere electron transfer processes.

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A Palladium-Catalyzed Oxa-(4+4)-Cycloaddition Strategy Towards Oxazocine Scaffolds

Synlett ◽

10.1055/s-0040-1706038 ◽

2021 ◽

Author(s):

Julian Garrec ◽

Alexis Archambeau ◽

Anaïs Scuiller ◽

Xueyang Liu ◽

Marie Cordier

Keyword(s):

Dft Calculations ◽

Palladium Catalyzed

AbstractA Pd-catalyzed oxa-(4+4)-cycloaddition between 1-azadienes and (2-hydroxymethyl)allyl carbonates is described. Aurone-derived azadienes furnished polycyclic 1,5-oxazocines in good yields. Interestingly, linear azadienes have also been involved and yielded monocyclic heterocycles with complete regioselectivity. DFT calculations were carried out to gain insight on this observation.

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