Grignard reagents carbon dioxide

By the action of carbon dioxide upon a suitable Grignard reagent, for example ... 

Alternatively, the solution of the Grignard reagent may be poured on to solid carbon dioxide (Dry Ice)—for experimental details, see under n-Valeric Acid, Section 111,84. 

We ve seen how Grignard reagents add to the carbonyl group of aldehydes ketones and esters Grignard reagents react m much the same way with carbon dioxide to yield mag nesium salts of carboxylic acids Acidification converts these magnesium salts to the desired carboxylic acids... 

Grignard reagent acts as a nucleophile toward carbon dioxide... 

Section 19.11 Carboxylic acids can be prepared by the reaction of Grignard reagents with carbon dioxide. 

Carboxylation (Section 19.11) In the preparation of a carboxylic acid, the reaction of a carbanion with carbon dioxide. Typically, the carbanion source is a Grignard reagent. 

The Grignard reagent from 2-thenyl chloride can be obtained by the use of the "cyclic reactor.However, rearrangement occurs in its reaction with carbon dioxide, ethyl chlorocarbonate, acetyl chloride, formaldehyde, and ethylene oxide to 3-substituted 2-methylthio-phenes, Only in the case of carbon dioxide has the normal product also been isolated. 

Oddo and Sessa claimed that 1-carboxyindole (375) was obtained on treatment of indole magnesium iodide with gaseous carbon dioxide. Majima and Kotake later reported that 3-carboxyindole (376) and not 375 was the main product obtained in this reaction improved yields of 376 were obtained when the reaction was carried out in anisole instead of ether.Subsequently, several workers have employed essentially this procedure, for the synthesis of 376. It has recently been shown, however, that both the acids 375 and 376 are formed in approximately equal amounts by the carbonation of the indole Grignard reagent (Kasparek and Hea-cook ). 

The Grignard reagents prepared from the activated magnesium appear to react normally with electrophiles. Thus reactions with proton donors, ketones, and carbon dioxide afford hydrocarbons, alcohols, and carboxylic acids, respectively. The reductive coupling of ketones to pinacols had also been accomplished with the activated magnesium. ... 

Organoytterbium chemistry has been developed in the last 20 years, although the development rate is much slower than the other lanthanides like samarium or cerium. Dianionic complexes that are produced from the reaction of ytterbium with diaryl ketones react with various kinds of electrophiles including carbon-heteroatom unsaturated bonds.35 Phenylytterbium iodide, a Grignard-type reagent, is known to have reactivity toward carbon dioxide,36 aldehydes, ketones,37,37 and carboxylic acid derivatives38,3811 to form the corresponding adducts respectively. 

Although pentacblorophenylmagnesium chloride can be made in tetrahydrofuran without the use of the entrainment method, the Grignard reagent in this solvent does not react with carbon dioxide to give pentachlorobenzoic acid in good yield.10... 

Grignard reagents react with carbon dioxide (dry iee) to form salts of carboxylie acids which in turn give eorresponding earboxylic acids after aeidifleation with mineral acid. 

After multiple steps, an organic halide can be converted to a carboxylic acid. The organic halide converts to a Grignard reagent, which reacts with carbon dioxide and then acidification forms the acid. Figures 12-13 and 12-14 illustrate the steps in this process. 

Carboxylic acids are obtained from Grignard reagents by reaction with carbon dioxide. Scheme 7.3 includes some specific examples of procedures described in Organic Syntheses. 

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