Hydrocarbons organomagnesium compounds

Organohthium and organomagnesium compounds are stable species when prepared m suitable solvents such as diethyl ether They are strongly basic however and react instantly with proton donors even as weakly acidic as water and alcohols A proton is transferred from the hydroxyl group to the negatively polarized carbon of the organometallic compound to form a hydrocarbon... 

The carbon-metal bonds of organolithium and organomagnesium compounds have appreciable carbamomc character Carbanions rank among the strongest bases that we 11 see m this text Their conjugate acids are hydrocarbons—very weak acids indeed The equilibrium constants for ionization of hydrocarbons are much smaller than the s for water and alcohols thus hydrocarbons have much larger pA s... 

Solutions of solvated organomagnesium compounds in largely hydrocarbon media have also been obtained by the use of hydrocarbon solvents containing small proportions of donors such as THF. 

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 add to polycyclic aromatic hydrocarbons under forcing conditions, bnt with electron-withdrawing substituents the addition occurs more easily. Alkyl Grignard reagents add 1,4 and/or 1,6 to nitroaromatics, and the nitronate intermediate may be converted to a number of useful products (equation 45). Aryl Grignards yield hydroxylamines (by means of a 1,2 process), which can be reduced to diarylamines. ... 

Organoaluminium compounds are stronger Lewis acids than organomagnesium compounds and form complexes with basic solvents. In ethers, for instance, R3AI either does not react at all with oxiranes or gives a very low yield of product and, accordingly, hydrocarbons are preferred as solvents. Important roles are played in the reaction by the molar ratio of R3AI to oxirane and the nature of the R substituents. 

Jones, Paul R., and Southwick, Everett (1970). V. Grignard Concerning Organomagnesium Compounds in Solution and Their Application to the Synthesis of Acids, Alcohols, and Hydrocarbons. of Chemical Education 47 290-299. 

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