Iron‐Catalyzed Oxidative Cleavage of Olefins and Alkynes to Carboxylic Acids with Aqueous tert‐Butyl Hydroperoxide

Abstract

A new method for the oxidation of aromatic olefins and alkynes has been developed using inexpensive iron(III) chloride hexahydrate (FeCl(3)center dot 6H(2)O, 5 mol%) catalyst in combination with commercially available aqueous 70% tert-butyl hydroperoxide (TBHP) as oxidant. The present system works well for aromatic alkenes and alkynes with both electron-donating and electron-withdrawing substituents being tolerated. The protocol is free from chromatographic purification and the carboxylic acids are obtained in high yields by simple filtration

Sequential [3+2] Cycloaddition/Air Oxidation Reactions: Triazoloyl Ion Assisted Oxidative Cleavage of Alkynes

“…Various oxidants have been reported to effect this transformation, including KMnO 4 , [1] RuO 4 , [2] molybdenum and tungsten polyoxometalates, [3] methylrhenium trioxide, [4] an osmium(VI)-oxo complex in tBuOOH, [5] InCl 3 /tBuOOH, [6] NaBO 3 /AcOH, [7] Cr VI / H 2 SO 4 , [8] and Pd(OAc)/ZnCl 2 /O 2 . [9] Recently, Hong et al [10] and Enthaler [11] independently reported the FeCl 3catalyzed cleavage of alkynes to carboxylic acids with tBuOOH and H 2 O 2 , respectively. In all of these methods, two molecules of a carboxylic acid were obtained from one molecule of an alkyne.…”

Synthesis of Pelorol and Its Analogs and Their Inhibitory Effects on Phosphatidylinositol 3-Kinase

“…The oxidation of 15 via TBHP can generate 16 [ 15 ]. The synthesis of pelorol ( 1 ) was completed by the esterification of 16 with MeI and the selective cleavage of aryl methyl ether with BI 3 .…”

2‐Oxo‐Driven Coupling Reactions of 2‐Oxo Aldehydes/2‐Oxo Iminium Ions and Hydroperoxides at Room Temperature

“…4‐Methylbenzoic Acid (4b): [10a], White solid (93 %, 126 mg). 1 H NMR (400 MHz, CDCl 3 ): δ = 8.03 (d, J = 8.1 Hz, 1 H), 7.30 (d, J = 10.0 Hz, 1 H), 2.46 (s, 1 H) ppm.…”

“…4‐Bromobenzoic Acid (4e): [10a], [10b], [10c], Solid (90 %, 181 mg). 1 H NMR (400 MHz, [D 4 ]methanol): δ = 7.82 (d, J = 8.4 Hz, 1 H), 7.55 (d, J = 8.4 Hz, 1 H) ppm.…”