Organomagnesium specie addition with

Organomagnesium compounds react with imines, prepared from 3-methoxy-2-naphth-aldehydes by a 1.4-addition mechanism. This reaction can be performed with high diastere-oselectivity. The method was applied for the synthesis of optically pure S-tetralones . Vinyhnagnesium bromide reacts as an acceptor with a ketone dimethyl hydrazone zincate 207, yielding a 1,1-bimetallic species, which can be reacted sequentially with two different electrophiles (equations 131 and 132) . The reaction proceeds via a metalla-aza-Claisen rearrangement, where the dimethylhydrazone anion behaves as an aza-allylic system . 

The enantioselective addition of organomagnesium compounds to ketones can be most conveniently performed by using a chiral auxiliary in the substrate molecule. Primary aUsyhnagnesium reagents react with aryl and heteroaryl ketones in the presence of magnesium TADDOLate at — 100°C, yielding products with up to 98% ee (equation 143). Chiral a-ketoacetals 214, prepared in two steps from a-substituted cinnamic aldehydes, add organomagnesium species with up to 98% diastereoselectivity (equation 144). 

Schlenk equilibrium [13] the simpler diorganomagnesium compounds are often easier to study [14,78,79] because of the absence of complications from additional halide ligands. As the organolithium compounds, organomagnesium species often react rapidly at ambient temperatures with substrates so that the charge transfer intermediates are not observed or reported. 

Arylboronic acids have traditionally been prepared via the addition of an organomagnesium or organolithium intermediate to a trialkyl borate. Subsequent acidic hydrolysis produces the free arylboronic acid. This limits the type of arylboronic acids one can access via this method, as many functional groups are not compatible with the conditions necessary to generate the required organometallic species, or these species may not be stable intermediates. 

The reaction of [LMn(CO)s] (L = CO, PRj, P(OR)3) with Li alkyls and organomagnesium halides gives the corresponding neutral acyl complex LMn(CO)4(COR). Where L = PRj or PCORj) only cis-addition products can be isolated. The reactions of this cationic species are instantaneous and faster than the isoelectronic LMfCO), (M = Cr, Mo, W) complexes whose rates are slow enough to be measured by conventional kinetic techniques . ... 

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