Magnesium compounds reactions

Organolithium and -magnesium compounds. Compared with extensive studies carried out on the Ni-catalyzed transmetallation reaction of Grignard reagents[43I,432], few examples of the Pd-catalyzed reactions of Mg are... 

Anhydrous diethyl ether is the customary solvent used when preparing organo magnesium compounds Sometimes the reaction does not begin readily but once started It IS exothermic and maintains the temperature of the reaction mixture at the boiling point of diethyl ether (35°C)... 

Preparation. Boron carbide is most commonly produced by the reduction of boric oxide with carbon in an electric furnace between 1400 and 2300°C. In the presence of carbon, magnesium reduces boric oxide to boron carbide at 1400—1800°C. The reaction is best carried out in a hydrogen atmosphere in a carbon tube furnace. By-product magnesium compounds are removed by acid treatment. 

The original cyclooligomerization noted above was conducted using alkyl aluminum, zinc and magnesium compounds ". Both open-chained and cyclic polymers were obtained in addition to dioxane. The principal macrocyclic component of the mixture was apparently 12-crown-4 (EO-4) which was said to be valuable as a high boiling neutral solvent... . " The reaction is shown below in Eq. (1.2). 

After a vigorous initial activity, whereby new fluorinated organometallic compounds were first synthesized, much of the research effort has decreased Some activity has been concerned with the reactions of perfluoroaromatic magnesium compounds... 

Research on perfluoroaromatic lithium compounds, like that of the magnesium compounds, has decreased since their initial discovenes Most of the recent effort IS concerned with reactions of the perfluoroaryllithium compounds with various substrates... 

Since the discovery of the first perfluoroalkyllithium and -magnesium compounds, their reactions with various carbonyl compounds [68] have been actively studied. These reactions could lead to functionally substituted fluoro compounds, as shown in equation 36... 

A modern variant is the intramolecular magnesium-ene reaction, e.g. the reaction of the alkene-allylic-Grignard compound 9 to give the five-membered ring product 10. This reaction proceeds regio- and stereoselectively, and is a key step in a synthesis of the sesquiterpenoid 6-protoilludene ... 

Addition reactions of various a-alkoxy lithium and a-alkoxy magnesium compounds 13, formed via the corresponding tributylstannanes, have been performed8. In every case the... 

These c-complexes have been less extensively studied than the r 3-allyltitanium derivatives. r 1 -Allyltitanocenes can readily be prepared from the corresponding magnesium compounds by reaction with Cp2TiCl2 or by reaction of preformed r 3-allyltitanium complexes with but-2-enyl halides [36]. Crotyl-type reagents, which are accessible only in the E-iso-meric form, add to aldehydes with an anti selectivity (Scheme 13.17). 

At present, only two organomagnesium derivatives of terphenyl ligands have been well characterized. However, the first terphenyl magnesium compound was reported more than 60 years ago with the generation of BrMgTriph in solution and its subsequent reactions to give the carboxylic acid, the acetyl derivative, and triphenylbenzophenone.28... 

There are several useful means for preparation of organomercury compounds. The general metal-metal exchange reaction between mercury(II) salts and organolithium or magnesium compounds is applicable. The oxymercuration reaction discussed in Section... 

Coupling of acetylenes and halides, copper-promoted, 50,100 Cuprous chloride, reaction with an organo-magnesium compound, 50,98... 

Macrocyclic compounds, stmcture, 712 Magnesium compounds, bis(tiimethylsilyl) peroxide reactions, 795-6 Malaria... 

Using deuterium instead of hydrogen reveals that the reaction seems to proceed similarly to the degradation of H2Al(tBuO)2Mg(OtBu)2AlH2 (compare Eq. 3). As in the case of the magnesium compound, equal amounts of di-... 

Condensation of the alkoxynaphthyldihydrooxazoles with 2-methoxy-l-naphthyllithium, prepared by bromine-lithium exchange, did not lead to the same product as the corresponding reactions with the magnesium compound, but, unexpectedly, to a rearranged isomeric 1 -bi-naphthyl derivative with high enantiomeric excess28. 

An unprecedented metallation was observed when 1,3-xylyl crown ethers are reacted with diarylmagnesium compounds. Reaction of l,3-xylene-15-crown-4 with diphenyl-magnesium gives in quantitative yield 2-(phenylmagnesio)-l,3-xylene-15-crown-4 (81), the structure of which was established by an X-ray crystal-structure determination... 

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