Deoxygenating agents

The aim of this work is the development of pyrene determination in gasoline and contaminated soils. For this purpose we used room temperature phosphorescence (RTP) in micellar solutions of sodium dodecylsulphate (SDS). For pyrene extraction from contaminated soils hexane was used. Then exttacts earned in glass and dried. After that remains was dissolved in SDS solution in the presence of sodium sulphite as deoxygenation agent and thallium (I) nitrate as heavy atom . For pyrene RTP excitation 337 nm wavelength was used. To check the accuracy of the procedures proposed for pyrene determining by RTP, the pyrene concentrations in the same gasoline samples were also measured by GC-MS. 

PI3 is emerging as a powerful and versatile deoxygenating agent. For example solutions of PI3 in CH2CI2 at or below room temperature... 

Derivatives 47-51 were prepared from the iV-oxide 46 using zinc as the deoxygenating agent (Scheme 11). The use of Zn in NH4CI solution led to the deoxy derivatives 47 and 48 in moderate yields. The reduction was clearly observed by NMR HETCOR experiments (HMQC and HMBC). When the reduction of the derivative 46 (R = CH2C1) was carried out under the same conditions, compound 51 was generated via a Zn-promoted reductive dimerization process <2001EJM771>. 

Intramolecular McMurry olefmation was realized by Furstner et al., who achieved synthesis of indol derivatives with a catalytic amount of TiCls. They employed zinc metal as a reductant and Me3SiCl as a deoxygenating agent... 

The oxide may be deoxygenated to the starting thiatriazole, but the oxygen is released rather slowly, even with the potent deoxygenating agent hexachlorodisilane. 

The use of condensating reagents, such as tetraphenylpyrophosphate [71], phos-phinic acid anhydride[71], carbodiimides [72], tosyl chloride [73], and a variety of deoxygenating agents has been explored [74—76], These systems have been shown to promote the cyclourethanization reaction in good yield under relatively milder conditions. 

The chemical properties ofPBr3 are similar to those ofPCb, althongh there is a difference in reactivity dne to the difference in the degree of polarity of the phosphoms-halogen bonds. PI3 is a powerful and versatile deoxygenating agent, effecting the conversion of selenoxides (R,R SeO) into selenides, for example. ... 

The radical anion derived from a ketone is called a ketyl. The dark blue, ster-ically and electronically stabilized benzophenone ketyl is widely used in solvent stills as a deoxygenating agent. 

A very interesting deoxygenation reaction, in which carbon monoxide serves as both, a deoxygenating agent as well as a carbonylating agent, was found recently by Bhaduri et al. The formation of phenyl isocyanate from nitrobenzene with carbon monoxide is catalyzed by trinuclear ruthenium clusters such as Ru3(CO),2 or [HRu3(CO) ] ... 

Hexachlorodisilane has been found to be a convenient deoxygenating agent of amine oxides and sulfoxides, and has been used in the synthesis of condensed bridged phosphinesIn addition, the first and only stereospecific desulfurization of phosphine sulfides reported to date was also accom-... 

Figure 3. Photoluminescence curves for a fresh milk powder (Control) irradiated with NUV light. Two glass bottles of milk powder were stored in a refrigerator for two weeks one bottle contained deoxygenating agent and the other none.

The reaction can be repeated many times by adding fresh azo derivative to the reaction vessel. Thus the amine acts as a catalyst, which is not the case for other deoxygenating agents such as P(OEt)3, the corresponding oxide of which could not be reduced by CO. 

As already reported in equation <16), in some cases is the metal itsel-f which acts as a deoxygenating agent o-f the nitroso group. From these reactions, coupling products o-f the ArN residue o-f the nitroso compound are usually obtained []53,54,55j ... 

Phosphorus trihalides can in some cases be used to halogenate alcohols (12.282) and to convert nitro compounds into cyanides (12.283). Carboxylic acids are converted to acyl halides (12.284) and deoxygenations can sometimes be effected (12.285). The triiodide is a useful deoxygenating agent. 

It should be noted that low-valent titanium complexes are powerful deoxygenating agents and, hence, can be used for various coupling reactions of organic molecules having oxygen functions. 

As in the case of nitroso compounds, sometimes it is the metal itself which acts as a deoxygenating agent of the nitro group. The reaction of N,N -ethylene-bis(salicilideneiminato)iron(II), Fe(Salen), with RNO2 (R = alkyl, aryl) leads to deoxygenation at room temperature (eqs. 18 and 19) [68] ... 

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