Hydrogens, tertiary oxidation with oxygen

Murahashi S-I, Nakae T, Terai H, Komiya N (2008) Ruthenium-catalyzed oxidative cyana-tion of tertiary amines with molecular oxygen or hydrogen peroxide and sodium cyanide sp3 C-H bond activation and carbon-carbon bond formation. J Am Chem Soc 130 11005-11012... 

The fluorination of adamantane and its derivatives can also be achieved with oxygen difluoride in the presence of sodium hydrogen carbonate as a hydrogen fluoride trap however, this reaction is complicated by competing oxidation.22 When the fluorination of adamantane is performed with cesium fluoroxysulfate, a mixture of monofluorinated products 4 and 5 arising from fluorination at tertiary and secondary sites, respectively, and difluorinated product 6 is obtained.23 The thermally initiated fluorination of adamantane using xenon difluoride gives a similar mixture but includes a small amount of trifluoride 7.24 25... 

The final step is the usual oxidation with alkaline hydrogen peroxide. Both groups on the boron 232 are now tertiary so an excess of oxidant must be used to drive both across to oxygen. The products are /-hexanol and the hydrate of the ketone 234. This doesn t affect the ketone synthesis, only the by-product. 

The formation of a methiodide indicated the tertiary character of the amine, and lack of any oxidation with periodic acid showed that a 1, 2-glycol grouping of two of the oxygens had to be excluded (43). Attempted condensation with nitromethane did not proceed and no reduction product was obtained by the use of sodium amalgam or hydrogen over platinum catalyst. Richardson and Warren also suggested that rosmarinecine was... 

Regio and bond selectivities of the reaction are high C(l) C(2) C(3) C(4) 1 40 35 35 and 1° 2° 3° is 1 (15-40) (180-300). The reaction with cis- or trans- isomers of decalin gives (after treatment with PPhs) alcohols hydroxylated in the tertiary position with a dsltrans ratio of 2 in the case of c/j-decalitL and of 30 in the case of trans-decalin (i.e., in the latter case the reaction is stereospecific). The authors [15p,q, 22] believe that the alkane oxidation by the system under consideration begins with hydrogen atom abstraction from the alkane by an oxygen-centered radical or radical-like species. 

The Gif system, which consists of triplet oxygen, acetic acid, pyridine, zinc and an iron catalyst, oxidizes saturated hydrocarbons mainly to ketones and gives minor amounts of aldehydes. Tertiary hydrogen is only substituted in exceptional cases. With the Gif-Orsay II system in which zinc is replaced by the cathode [divided cell, cpe at — 0.6 to —0.7 V vs see, trifluoroacetic acid, pyridine, Fe30(0Ac)6Pyr3.5], adamantane is converted in 3.8% coulombic yield the ratio of attack at a secondary tertiary CH bond (C /C ratio) is 15.0. Comparable conversions were carried out with cyclododecane to afford 21% oxidation with a ratio of alcohol ketone = 1 14. TranS decalin yielded 22% product, consisting of 0.6% 9-ol, 0.9% l-ol, 9.0% 1-on 0.65% 2-ol and 11% 2-one. A radical mechanism for this conversion can be excluded since for the cobalt-catalyzed radical oxidation of trans-decalin the C /C ratio is 0.13, which is far removed from 36 found with the Gif system. 

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