Magnesium compounds reagents

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... 

Seyferth prepared a-halogenoalkyl-lithium and -magnesium compounds by treating the appropriate gem-dihalides with butyllithium or with Grignard reagents at low temperature, and then used the products to prepare acyclic and cyclic a-halogenoalkyltin compounds (57-60). Typical examples are shown in the following equations. 

Preparation of allyltitaniums of the type (allyl)Ti(OiPr) 3 from the corresponding allyl-lithium or -magnesium compounds and ClTi(OiPr)3 by transmetallation and their subsequent synthetic utilization have attracted considerable interest because of the advantageous reactivity of the allyltitaniums as compared to other allylmetal complexes in terms of chemo-, regio-, and diastereoselectivity [3], The preparation of certain allyllithium or -magnesium reagents, however, is not necessarily easy, which would seem to limit the utility of this method. 

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). 

Organo-magnesium compounds as nucleophiles. Use of Grignard reagents in syntheses. ... 

Gngnard reagents - [BROMINE COMPOUNDS] (Vol 4) - [ESTERS, ORGANIC] (Vol 9) -from benzene [BENZENE] (Vol 4) -chemiluminescence [LUMINESCENTMATERIALS - CHEMILUMINESCENCE] (Vol 15) -magnesium alkyls from [MAGNESIUM COMPOUNDS] (Vol 15) -reaction of propylene oxides [PROPYLENE OXIDE] (Vol 20) -for silanes [SILICON COMPOUNDS - SILANES] (Vol 22) -for sulfoxide synthesis [SULFOXIDES] (Vol 23)... 

Alkyltrisidialkylamino)titanium derivatives, R Ti(NR2)3. ) These reagents are readily available by reaction of halotris(dialkylamino)titanium with organolithium or -magnesium compounds. The reagents, prepared in situ in ether, react with nonenolizable aldehydes to give tertiary amines (1), possibly via an iminium salt (equation I). With enolizable aldehydes and ketones, the reaction results in enamines after nonaqueous workup. 

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