Ketones aerobic dehydrogenation

Cyclic ketones can be aerobically dehydrogenated to cyclic enones, using a new catalyst, Pd(DMSO)2(TFA)2. For cyclohexanones, complete oxidation to the phenol is typically avoided. ... 

PV2M010O40 has usually been used in the acid form. H5PV2M010O40 catalyzes aerobic oxidative cleavage of cycloalkanes, 1-phenylalkanes, and ketones. For example, the oxidation of 2,4-dimethyl cyclopentanone and 2-methylcyclo-hexanone gives 5-oxo-3-methylhexanoic acid and 6-oxoheptanoic acid, respectively, in yields higher than 90% [285, 286). Bromination of arenes with HBr [287), oxidative dehydrogenation of cyclohexadiene [288, 289) and a-terpinene [290), oxidation of 2,4-dimethylphenol [291) and sulfides [292) are other examples. 

Table XXXVI is a list of some catalytic photochemical redox transformation of organic reactants by (Q or H)3PW 204o. In the presence of UV light, Q3PW12O40 reacts with paraffins, arenes, alcohols, alkyl halides, ketones, nitriles, thioethers, and water. Under either anaerobic or aerobic conditions, decarboxylation, dehydrogenation, dimerization, polymerization, oxidation, and acylation takes place.

Using a commercially available AC ( 50wt%), various secondary benzylic alcohols were dehydrogenated aerobically to the corresponding ketones [62, 63]. 

For direct aerobic a, -dehydrogenation of aldehydes and ketones with a new Pd(TFA)2/4,5-diazafluorenone catalyst, the turnover-limiting step is a-C-H cleavage. Means of oxidative cleavage of C-C bonds in aldehydes by O2, cyclic ketones " by nicotinium dichromate, and a-hydroxy ketones by O2 have been discussed. 

Intermolecular direct C(3)-alkenylation of indoles using palladium(II) as catalyst and oxygen as the oxidant has been achieved. The reaction shows complete regio- and stereo-selectivity all products are ii-isomers at the C(3)-position, and no Z-isomers or 2-substituted products are detected. Aerobic a, -dehydrogenation of aldehydes and ketones is catalysed by Pd(TFA)2/4,5-diazafluorenone. The cleavage of a-C-H bond of the ketone has been identified as the turnover-limiting step of the catalytic mechanism. ... 

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