The Grignard reagent an organometallic compound

Carboxylic acid groups can also be installed in molecules using the reaction of an organometallic compound with carbon dioxide. This is a reductive method since the carbon dioxide is reduced to a carboxylic acid by formation of a new carbon-carbon bond. Both Grignard reagents and organolithium compounds work well in this reaction. 

Although the first report of an organometallic compound of the heavier alkaline earth metals appeared near the beginning of the twentieth century,291 the RMX Grignard analogs of Ca, Sr, and Ba never fulfilled their promise as general-purpose synthetic reagents. More difficult to form, less thermally stable, and less selective in their reactions than their Mg counterparts, the literature data of the compounds was often contradictory, and many syntheses were irreproducible (see Calcium, Strontium, and Barium in COMC (1982)). 

A method based on equation 21 may be performed, where the organic residue of an organometallic compound becomes derivatized with excess dimethylphenylchlorosUane (67) and determined by GC, using cumene (i -PrPh) as internal standard. Although lithium alkoxide impurities also react with 67, the product appears at a different retention time. The method is also suitable for Grignard reagents. ... 

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