Phenyhnagnesium bromide

When compound 7 is treated in a 1 1 ratio with phenyhnagnesium bromide using inverse addition, the reaction is sluggish and stops at the ketone stage giving a-benzamidobenzalacetophenone (29) in low yield as the only isolable product. 

The formation of phenyl esters from boronic acid and phenyhnagnesium bromide in THF is a fast liquid reaction involving contacting of two reactants, Rj (boronic acid) and R2 (phenyhnagnesium bromide), dissolved in the same solvent to yield a liquid mixture [48,108], This mixture is post-processed by a fast hydrolysis. This step was performed conventionally in a batch mode. 

An alternative way of making tamoxifen is the direct interaction in the Grignard reaction of the a-ethyldeoxybenzoin and the 4-(2-dimethylaminoethoxy)phenyhnagnesium bromide, and further dehydration of the resulting carbinol (28.2.9) followed by subsequent separation of the mixture of E and Z isomers [49-56]. 

The only reported example of the use of O-phenylhydroxylamine Ig for electrophilic amination of carbanions is the conversion of phenyhnagnesium bromide into aniline. ... 

Recently, a direct kinetic study on the amination of substituted phenyhnagnesium bromides using Af,Af-dimethyl O-mesitylenesulfonyl hydroxylamine 3b as amination reagent has been reported by Erdik and Ate Ulkii . Rate data, the Hammett relationship and activation entropy support an Sn2 displacement of the carbon nucleophile on the electrophilic nitrogen. These results are consistent with the competition kinetics for electrophilic amination of substituted phenyl Grignard reagents with O-methylhydroxylamine In. ... 

The first example of the amination of Grignard reagents with oximes is the reaction of benzaldoxime 6a with a-naphthylmagnesium bromide (equation 24, path a) to yield a-naphthylamine (Scheme 53, path d, electrophilic amination product). In contrast, the reaction of benzaldoxime with phenyhnagnesium bromide (equation 24, path b) was reported to give Af-benzhydrylaniline (Scheme 53, path e product). 

Dialkyl peroxyphosphates 67 or monoperoxy phosphates 68 react with phenyhnagnesium bromide to afford tcrt-butyl phenyl ether in high yield together with dialkylphosphoric acid or alkylphosphoric acid in moderate yields (equation 102). 

A rather more complex scheme is required for the preparation of a derivative that bears a trifluoromethyl substituent on one of the benzene rings. The scheme starts with the condensation of the nitrile group in (32-1) with phenyhnagnesium bromide to give the corresponding imine treatment with aqueous acid leads to the substituted benzophenone (32-2). The future methyl on one of the bridges is introduced in a sequence involving the addition of a trimethylsulfonium yhde. 

Phenyhnagnesium bromide, 415,673 Phenylmagneshim chloride, 415 Phenylmaleic anhydride, 998 N-Phenylmaleimide, 462, 845-846,1134... 

Reaction of various substituted phenyhnagnesium bromides with hexafluoropropene under pressure at ambient temperature had been effected on the 0.2-0.6 g mol scale without incident. An attempt to scale up to 0.8 g mol with pheny hnagnesium bromide led to an explosion. 

In principle either strategy is acceptable in practice the one involving phenyhnagnesium bromide is nsed. 

An alternate preparation has been described in which phenyhnagnesium bromide is treated with selenium and then with bromine. Diphenyl diselenide is then obtained (66% yield) by air oxidation of the intermediate phenylselenol. ... 

Another reaction of radicals is rearrangement. Radicals are generally less susceptible to rearrangement than are carbocations, and the 1,2 hydrogen or carbon shifts seen with carbocations are not observed with radicals. However, apparent phenyl migration has been observed (Scheme 4.37). Treatment of neophyl chloride with phenyhnagnesium bromide and cobaltous chloride produced isobutylbenzene... 

Enantioposition-selective asymmetric cross-coupling has also been successfully applied to the synthesis of axially chiral biaryl molecules (Scheme 11).155],[56] Reaction of the achiral ditriflate 52 with 2 equiv of phenyhnagnesium bromide in the presence of lithium bromide and 5 mol % of PdCl2[(5)-phephos (10b)] at -30 °C for 48 h gave an 87% yield of the monophenylation product (S)-53, which is 93% ee, and a 13% yield of diphenylation product 54. The enantiomeric purity of the monophenylation product... 

Synthetic Applications The intramolecular 1,4-chloroamination of 108 was apphed to the synthesis of amaryllidaceae alkaloids a- and ylycotane (Scheme 11.40) [129]. The hexahydroindole 109 obtained was transformed to the target alkaloid a-lycorane by a copper-catalyzed reaction with 3,4-(methylene-dioxy)phenyhnagnesium bromide, followed by hydrogenation, the Bischler-Napieralski cyclization, and LiAlH reduction. When the Bischler-Napieralski cyclization was carried out before the hydrogenation, ylycorane was the sole product. 

Scheme 1338. A representation of a pathway from thebaine to phenyldihydrothebaine, the product resnlting from the addition of phenyhnagnesium bromide to thebaine. After Holmes, H. L. Stork, G. The Alkaloids, Vol. 2, Academic, New York, 1952, p. 198.

Preparation by reaction of phenyhnagnesium bromide with 2-hydroxy-3-meth-oxybenzonitrile in ethyl ether in a water bath for 2.5 h (88%) [648]. 

---