- Copper-Catalyzed Oxidative Cyclization of Carboxylic Acids
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A method for converting C-H to C-O bonds through oxidative cyclization of carboxylic acids to generate lactone products is described. The reaction employs catalytic amounts of Cu(OAc)2 and potassium persulfate as the terminal oxidant and is performed open to air in an aqueous acetic acid solvent system. Preliminary mechanistic studies suggest that substrate oxidation likely proceeds by sulfate radical anion and that the Cu catalyst has no influence on the product-determining step. These conclusions differ from related investigations that propose the intermediacy of a carboxylate radical.
- Sathyamoorthi, Shyam,Du Bois
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supporting information
p. 6308 - 6311
(2016/12/23)
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- Novel Carboxymethylation of Styrene Derivatives by Mn(3+)-Mediated Electrooxidation
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Anodic oxidation in a mixed solvent of acetic acid and acetic anhydride containing a variety of styrene derivatives, small amounts of Mn(OAc)2*4H2O and Cu(OAc)2*H2O brought about a facile carboxymethylation to give the corresponding γ-butyrolactones as the main products in good yields.
- Shundo, Ryushi,Nishiguchi, Ikuzo,Matsubara, Yoshiharu
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p. 185 - 188
(2007/10/02)
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- Mechanisms for Manganese(III) Osidations with Alkenes
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In the reaction of manganese(III) acetate with carboxylic acids and alkenes, three distinct processes have been identified which involve the alkene and two processes which are independent of alkene.A combination of product studies, rearrangements, dilution experiments and literature kinetic data allow the proposal of a unified mechanistic picture to describe these processes.Specifically, the role of α-H acidity of the carboxylyic acid component, electron deficient radical additions, metal complexed organic radicals, and the importance of an oxo-centered manganese(III) triangle are discussed as they relate to the lactone annulation reaction.Single electron transfer oxidation of alkenes is described as a route toward 1,2-diacetates of alkenes within the 8.1-7.5 eV I.P. range.Three less common modes of Mn(III) reaction are discussed and compared with the two primary processes of lactone annulation and 1,2-diacetate formation.
- Fristad, William E.,Peterson, John R.,Ernst, Andreas B.,Urbi, Gordon B.
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p. 3429 - 3442
(2007/10/02)
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- Manganese(III)-Mediated γ-Lactone Annulation
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The annulation of a γ-lactone ring onto an alkene by manganese(III) acetate oxidation of acetic acid was investigated.The regioselectivity of addition to unsymmetrically substituted alkenes is reported along with the stereoselectivity of addition to various acyclic and cyclic alkenes.Alkenes with ionization potentials above 8.2 eV were found to react in good yield.The role of acetic anhydride in these reactions was studied, and it was shown to be oxidized faster than acetic acid and also led to different products.The fate of oxidized acetic acid or anhydridein the absence of suitable acceptor molecule has also been quantitatively identified.The relationship of enolizability, or C-H acidity, of the carboxylic acid being oxidized was established quantitatively.
- Fristad, William E.,Peterson, John R.
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