- A NEW SYNTHESIS OF α-IODO CARBOXYLIC ACID USING IODINE-COPPER SALT
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Direct α-iodination of some carboxylic acids, namely, acetic acid, propionic acid, butyric acid, and valeric acid, using iodine-copper salt, gave the corresponding α-iodo carboxylic acid in high yield.This new synthetic method afforded several advantage over classical α-iodo carboxylic acid procedures.
- Horiuchi, C. Akira,Satoh, J. Yasuo
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- Photoiodocarboxylation of Activated C=C Double Bonds with CO2 and Lithium Iodide
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The photolysis at 254 nm of lithium iodide and olefins 1 carrying an electron-withdrawing Z-substituent in CO2-saturated (1 bar) anhydrous acetonitrile at room temperature produces the atom efficient and transition metal-free photoiodocarboxylation of the C=C double bond. The reaction proceeds well for terminal olefins 1 to form the new C-I and C-C σ-bonds at the α and β-positions of the Z-substituent, respectively, and is strongly inhibited by polar protic solvents or additives. The experimental results suggest that the reaction channels through the radical anion [CO2?-] in acetonitrile, yet involves different intermediates in aqueous medium. The stabilizing ion-quadrupole and electron donor-acceptor interactions of CO2 with the iodide anion play a crucial role in the reaction course as they allow CO2 to penetrate the solvation shell of the anion in acetonitrile, but not in water. The reaction paths and the reactive intermediates involved under different conditions are discussed.
- Mello, Rossella,Arango-Daza, Juan Camilo,Varea, Teresa,González-Nú?ez, María Elena
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p. 13381 - 13394
(2018/11/20)
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- Oxidative Coupling of Carboxylic Acid Dianions: The Total Synthesis of (+/-)-Hinokinin and (+/-)-Fomentaric Acid
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The oxidative coupling of carboxylic acid dianion derivatives provides the key intermediates needed for efficient syntheses of the symmetrical lignan hinokinin (9) and the unsymmetrical fungal metabolite fomentaric acid (22).Racemic hinokinin (9), a targed chosen to test the facility of dianion oxidative coupling in the presence of electron-rich aromatic rings, is prepared in an overall conversion of 61 percent from 3,4-(methylenedioxy)hydrocynnamic acid.Racemic fomentaric acid (22), a trisubstituted succinic acid derivative, results from a straightforward two-stepsequence that proceeds in an overall yield of 40 percent from eicosanoic acid.Preliminary studies demonstrate the utility of oxidative coupling in the synthesis of novel surfactant prototypes.
- Belletire, John L.,Fry, Douglas F.
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p. 2549 - 2555
(2007/10/02)
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- α-Iodination of Some Aliphatic Acids. Substituent Effect and Optimum Conditions
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The chlorosulfonic acid promoted α-iodination of some aliphatic acids in 1,2-dichloroethane has been studied.In contrast to the bromination, the effect of substituents on the rate shows not only a polar effect but also a steric effect in view of Taft's equation: , where ρ? = -1.20 and δ = 1.55 at 80 deg C.The transition state is discussed, which involves the electrophilic addition of I2 to a ketene intermediate.Aliphatic acids with less steric hindrance at the α-position, except acetic acid, are α-iodinated in good yields (ca. 80-100percent).The optimumconditions for α-iodination of long-chain aliphatic acids with caprylic acid as a model substrate are described.
- Ogata, Yoshiro,Watanabe, Shinya
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p. 2831 - 2834
(2007/10/02)
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