Organomagnesium compounds oxidation

Magnesium methylate is used as a drying agent for alcohols and other organic solvents and as an intermediate in various manufacturing processes, eg, for organomagnesium compounds (79), orthocarbonic esters (80), and for oxide coatings. 

IV. ANODIC OXIDATION OF ORGANOMAGNESIUM COMPOUNDS A. Simple DIorganomagnesium Compounds... 

The reaction of aryl electrophiles with organomagnesium compounds is known as Kumada or Kumada-Tamao-Corriu reaction. The most common leaving groups in the electrophile are halogen atoms and, among them, chlorine is the most wanted due to the good availability and the low price of aryl or heteroaryl chlorides. Unfortunately, the oxidative addition of a metal center to an aryl chloride is a difficult reaction and many efforts have been made to overcome existing limitations. 

Being very strong bases, organometallic compounds are capable to start the polymerization (7, 12, 30, 51, 62). If organomagnesium compounds are used, the interaction of magnesium cations with lactam anions can probably reduce the dissociation of the salt analogous the basic character is certainly weakened in lactam complexes formed by addition of hydrated oxides of Ti, Zr, Hf, Th or Ce (48). 

The most important determination is normally the concentration of carbon-magnesium-bonded species in solution. For routine estimation of this concentration for freshly prepared solutions of organomagnesium compounds, an aliquot of the test solution may be added to an excess of standard acid, and then back-titrated with sodium hydroxide. However, this simple determination of total base will give a high estimate of organomagnesium content if products of hydrolysis or oxidation are present. Analytical methods based on the determination of the hydrocarbon formed on hydrolysis of the organomagnesium compound... 

Organomagnesium compounds usually resemble organolithium compounds in their reactions with nitrogen heterocyclic aromatic compounds [E, G], but they generally give inferior results for preparative purposes. Thus, as in the case of organolithium compounds, addition normally occurs at the 2-position of pyridine, and subsequent elimination or oxidation gives the 2-substituted pyridine [1] ... 

Reaction with deuterium oxide, O-deuterated alcohols or acids is commonly used to provide evidence for the formation of organomagnesium compounds (e.g. see Ref. [3]). Although the presence of water normally inhibits the reaction of organic halides with magnesium, it is noteworthy that under appropriate conditions a Barbier procedure was successful [4] ... 

An alternative two-step procedure is the oxidation of an organoboron intermediate, prepared from the organomagnesium compound (see Section 15.1). 

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