Oxygen atom transfer agents

The reactions of a number of ozonides and alkenes in the presence of BF3 Et20 resulted in the formation of E- and Z-l,2-dioxolanes in 12-70% yields (Scheme 30) <83JA6279>. 2,5-Dimethyl-thiophene endoperoxide can act as a sulfur- or oxygen-atom transfer agent in analogous reactions to those shown by furan endoperoxides <86JA2775>. 

A very broad class of primary oxidants act as oxygen atom transfer agents, the most widely nsed oxidants in oxidation catalysis. These inclnde peracids or their anion forms, snch as MCPBA or oxone (O-OSOs ) as well as A-oxides snch as A-methyl morpholine A-oxide or hypochlorite ion. They all have general structure XO, where X is a good leaving gronp. 

Dimethyldioxirane (52) and other methyldioxiranes are easily generated peroxides which have proved to be very useful oxygen atom transfer agents alkenes, sulfides and amines can all be oxidized and dimethyldioxirane is reduced to acetone. ... 

The pyrimido-pteridine N-oxide (168) is well known as an electron acceptor and oxygen atom transfer agent. Its use for the hydroxylation of phenols has now been described.Ultra-violet light irradiation of (168) in acetonitrile solution allows conversion of phenol to a mixture of catecol and hydroquinone, cresol to 4-methylcatecol, tyrosine methyl ester to dopa methyl ester (169), and the pain killer acetaminophen (170) to (171). The reaction is initiated by light induced electron transfer from the phenol to the... 

Olefin oxidations can also be accomplished by the palladium nitro complex [(MeCN)2PdCl(N02)] (45), which has the capability to act at the same time as an oxygen atom transfer agent and olefin activator [116, 119-121]. Stoichiometric reaction of 45 and 1-decene under nitrogen atmosphere revealed the formation of palladium nitrosyl species identified as [PdCl(NO)] . At 60°C in air, the toluene solution of 45 catalyzed the oxidation of 1-decene to 2-decanone with a TON of 4. The same reaction carried out at room temperature afforded within 24 h a TON of 2. 

Khan MMT, Venkatasubramanian K, Shirin Z, Bhadbhade MM (1992) (Ethylenediaminete-traacetato)nitrosylruthenium, an efficient oxygen-atom transfer agent. J Chem Soc Dalton Trans 1031-1035... 

Recently, the HOF CH3CN complex (shown below) has been found to be an excellent oxygen atom transfer agent toward a variety of functional groups ... 

So-called hypofluorous acid, which is not significantly acidic, serves as a useful oxygen atom transfer agent. 

Jacobsen applied manganese(III)-salen complexes for sulfide oxidation [57a]. It turned out that sodium hypochlorite was too reactive for the selective oxidation of sulfides but when employing iodosylbenzene as the oxygen atom transfer agent, no over-oxidation to sulfone was observed [106]. Disadvantages of iodosylbenzene are the poor solubility, low oxygen atom efficiency and high cost for practical application. 

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