Magnesium dialkyl

For carbon substitution, magnesium dialkyls (and biphenyl) and lithium alkyls are effective in the absence of metal halides. Conditions have also been found for cyanide substitution and for hydro-formylation. 

Reactions of magnesium dialkyl malonate or magnesium hydrogen alkyl... 

In earlier sections it has been shown that the reaction of a magnesium dialkyl with one equivalent of a primary amine usually affords the primary amido derivative. However, it is also possible to effect elimination of the second equivalent of alkane to give magnesium imides. The reaction of MgEt2 with aniline in thf proceeded via an amido intermediate which eliminated ethane to yield the hexameric imido compound [ (thflMgNPhJg] which was the first homometallic magnesium imide to be structurally characterized. Equation (3.9). 

An equilibrium involving substituent exchange between magnesium dialkyls and magnesium dialkoxides recently has been postulated in order to explain stereoselectivity of certain Grignard reduction reactions (64). 

Group II provides the crystalline Be(CH3)2, the very reactive magnesium dialkyls, and compounds of the alkaline-earths such as the dimethyls of Ca, Sr, and Ba.( )... 

Magnesium dialkyls, R Mg, and the alkyl magnesium halides, RMgX (where R is an alkyl groups such as n-butyl or //-hexyl and X is a halogen)... 

II. Magnesium hydride is formed when magnesium dialkyls (diethyl, dibutyl, diphenyl) or the corresponding Grignard compounds are heated to 175-200°C under high vacuum for several hours. 

The magnesium dialkyls are colourless solids, which react readily with oxygen and water and which usually decompose without melting at high temperatures. The pathways followed in their thermal decomposition are typical of many alkyl derivatives of main group and of transition elements. Where a ( -C—H is present, as in Et Mg, jS-hydrogen transfer predominates with loss of alkene ... 

The second group alkyls form complexes with heterocyclic bases, many of which are brightly coloured. The occurrence of such coloured compounds is uncommon in main group chemistry. For example 2,2 -bipyridyl forms yellow Me Bebipy, red Et Bebipy and orange-red Et Znbipy. Similarly o-phenanthroline forms violet complexes with magnesium dialkyls. The colours may arise by transfer of an electron from the metal—carbon bonds as a group to the lowest vacant Ti-orbital of the heterocycle. 

Rare Earth Borohydride/Magnesium Dialkyl in Stoichiometric Amount... 

The half-sandwich complex is much less prone to polymerize ethylene when combined with magnesium dialkyl. We observed that Cp Nd(BH4)2(THF)2/10 BEM is quite active but 20% vinyl end groups are detected by H NMR, highlighting a substantial occurrence of /3-H abstraction [26 unpublished results]. 

The organotin equivalents of Grignard reagents and the organotin equivalents of magnesium dialkyls are made according to the equations below ss. 

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