Phenylmagnesium bromide carboxylation

Phenylisothiocyanate, 1074—1075 Phenylketonuria (PKU disease), 1065 Phenyllithium, 549 Phenylmagnesium bromide carboxylation of, 752 preparation of, 550, 921 reaction of... 

There has been some investigation of auxiliary-controlled cycloadditions of azir-ines. Thus, camphor-derived azirine esters undergo cycloaddition with dienes, with poor diastereoselectivity [70]. The same azirines were also observed to react unselectively with phenylmagnesium bromide. Better selectivities were obtained when Lewis acids were used in the corresponding cycloaddition reactions of 8-phe-nylmenthyl esters of azirine 2-carboxylates (Scheme 4.48) [71]. The same report also describes the use of asymmetric Lewis acids in similar cycloadditions, but mediocre ees were observed. 

The Michael acceptor can be an a, -unsaturated carboxylic ester. This possibility is illustrated with the conjugate addition of phenylmagnesium bromide to ethyl arecaidinate, which leads to 4-phenylnipecotic acid (equation 33). 

A fairly straightforward scheme, called the Barbier-Wieland degradation, was at that time used for determining the number of carbon atoms in an ahphatic acid fragment. This involves first converting the carboxylic acid 11-1 to the corresponding ester 11-2 (Scheme 1.11). Reaction of the ester with phenylmagnesium bromide leads to carbinol 11-3. Treatment with acid leads to dehydration and formation of the olefin 11-4. Oxidation by one of several methods cleaves... 

Reaction of a Grignard reagent with carbon dioxide, followed by treatment with aqueous HCI, gives a carboxylic acid. Propose a structural formula for the bracketed intermediate formed by the reaction of phenylmagnesium bromide with CO2, and propose a mechanism for the formation of this intermediate ... 

Phenylmagnesium bromide Ketones from carboxylic acid esters s. 12, 861... 

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