Conversion of Olefins into Ketones by an Iron‐Catalyzed Wacker‐type Oxidation Using Oxygen as the Sole Oxidant

Abstract

We describe a mild and operationally simple procedure for the oxidation of olefins into ketones. The reaction is catalyzed by the hexadecafluorinated iron-phthalocyanine complex FePcF with stoichiometric amounts of triethylsilane as an additive under oxygen atmosphere to give ketones in good to high yields with excellent chemoselectivity and functional group tolerance. Ketone formation proceeds in up to 95 % yield and with 100 % regioselectivity while the corresponding alcohols were observed as side products.

Synthesis of Euchrestifoline Using Iron‐ and Palladium‐Catalyzed C–H Bond Activations

“…Obviously, the iron complex FePcF 16 used as catalyst requires no induction period and after a reaction time of 10 hours, the reaction progresses only very slowly. Stirring of the chroman‐4‐one 6a under our standard reaction conditions provided the chroman‐4‐ol 6b , thus emphasizing our previous finding that the alcohol as by‐product is formed by an iron‐catalyzed reduction of the ketone . Moreover, we found that the iron‐catalyzed Wacker‐type oxidation proceeded in shorter reaction times when using triphenylsilane as reductive additive (5 mol‐% of FePcF 16 , 2.0 equiv.…”

“…In the course of our project directed towards the development of sustainable catalysis using iron, we have recently described an iron(III)‐catalyzed Wacker‐type oxidation for the conversion of olefins into ketones . An alternative iron‐catalyzed Wacker‐type oxidation has been independently reported by Han et al Following our protocol, vinylarenes including those containing internal double bonds are transformed into the corresponding arylketones at room temperature by using hexadecafluorophthalocyanine‐iron (FePcF 16 ) as catalyst in the presence of stoichiometric amounts of triethylsilane as reductive additive and oxygen as terminal oxidant …”

Synthesis and evaluation of novel chromanone and quinolinone analogues of uniflorol as anti-leishmanial agents

“…The resulting solution was stirred at 90 C for 3 h in a Dean Stark apparatus and then cooled. The cold mixture was evaporated in vacuo, and the residue purified by flash column chromatography to afford 31, as an off-white solid, in accordance with literature data for the compound [35] (1.95g, 57%).…”

“…Upon completion, the solvent was removed in vacuo, and the residue purified by flash chromatography to give 13c as a pale golden oil (32mg, 27%). IR ν max (neat) 4-amino-3-iodobenzonitrile (35) The compound was prepared and characterized as previously described in Ref. [36].…”

Iron‐Catalyzed Wacker‐type Oxidation of Olefins at Room Temperature with 1,3‐Diketones or Neocuproine as Ligands**

“…described a Wacker‐type oxidation of alkenes to ketones in ethanol at 80 °C using iron(II) chloride as catalyst, polymethylhydrosiloxane (PMHS) as additive, and air as sole oxidant [10a] . We described the conversion of olefins into ketones proceeding in ethanol at room temperature using iron(II)–hexadecafluorophthalocyanine as catalyst, triethylsilane as additive, and oxygen as sole oxidant [10b] . In the course of our project directed towards the application of iron compounds as catalysts for operationally simple and convenient synthetic transformations, [13] we have been searching to expand the toolkit for the iron‐catalyzed Wacker‐type oxidation.…”