Ketonization of methylenic carbons

The [Con(bipy)2 ]2+ species has also been reported to activate hydrogen peroxide and ter -butyl hydroperoxide for the selective ketonization of methylenic carbons, the oxidation of alcohols and aldehydes, and the dioxygenation of aryl olefins and acetylenes (36). Later reports (37), however, while confirming that the cobalt complexes did indeed cata-... 

D KIE determinations in the ketonizations of methylenic carbons with dioxygen (02) catalysed by Fell(DPAH)2 complex... 

Table VIb. Products and Conversion Efficiencies for the Fe(PA)2, 11, Catalyzed (3.5 mM) Ketonization of Methylenic Carbon and the Dioxygenation of Acetylenes and Arylolefins by H202 (56 mM) in Pyridine/AcOH (2 1)...

Table Vic. Ketonization of Methylenic Carbons and Dioxygenation of Aryl Olefins, Acetylenes, and Catechols via the Fe2+(DPAH)2, 16, Induced Activation of Dioxygen in 1.8 1 py/HOAc...

When the HOOH/Fe(II)(PA)2 ratio is large, the Feli(PA)2 (at low concentration) is rapidly transformed to (PA)2FeiilOFeliKPA)2, which activates the remaining HOOH for the ketonization of methylenic carbons (Table 5-2 and Scheme 5-1, and Chapter 4) 2 and eliminates reduced iron for the Fenton process. 

Direct ketonization of methylenic carbons, and the dioxygenation of aryl olefins, acetylenes, and catechols... 

An earlier section of this chapter (Table 6-2 and Scheme 6-1) describes selective ketonization of methylenic carbons via activation of O2 by Fe RDPAH)2 to give (DPAH)2Fe llOOFe IKDPAH)2 as the reactive intermediate. 

COPPER(I)/(t-BuOOH)-INDUCED ACTIVATION OF DIOXYGEN FOR THE KETONIZATION OF METHYLENIC CARBONS"... 

Tung, H.-C., Kang, C., and Sawyer, D.T. (1992) Nature of the Reactive Intermediates from the Iron-Induced Activation of Hydrogen Peroxide Agents for the Ketonization of Methylenic Carbons, tlie Monooxygenation of Hydrocarbons, and the Dioxygenation of Arylolefins, J. Am. Chem. Soc. 114, 3445-3455. 

Mimoun and Roch used hydrazobenzene (PhNHNHPh) for oxygenation of cyclohexane, cyclohexene, and toluene." The most active complex was formed from FCCI2 and carboxylic acid in the presence of hydrazobenzene. Davis et al. used Fepy4Cl2 and PbC02H for the same reaction and proposed the hydroperoxide complex [Fe "(OOH) PhNNHPh)] as an active species."" Sheu et al. used Fe" complexes (Fe(PA) or Fc(DPAH)2) (PA picolinato) for the monooxygenation of saturated hydrocarbons, especially ketonization of methylenic carbons. "" This system was applied to the hydroxylation of aromatic hydrocarbons as reaction mimic for tyrosine hydroxylase."" With phenol as a reactant, the dominant product was catechol. 

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