Phenylmagnesium bromide methyl

Aryl-2-phenyl-4,5-dihydropyridazin-3(2//)-ones react either with phenylmagnesium bromide or with phenyllithium to give 6-aryl-2,6-diphenyl-l,4,5,6-tetrahydropyridazin-3(2//)-ones (135) (products of 1,2-addition to the azomethine bond), while 2-methyl-6-phenyl-4,5-dihydropyridazine-3(2//)-one reacts with two equivalents of phenylmagnesium bromide at the carbonyl and azomethine group to produce 2-methyl-3,3,6,6-tetraphenyl-hexahydropyridazine (136) (Scheme 53) (80JPR617). 

Methyl-2-phenyl-5-oxazolinone (196) with phenylmagnesium bromide gives (197) (65AHC(4)75). 

The nitration of l,2,5-selenadiazolo[3,4-/] quinoline 77 with benzoyl nitrate affords the 8-nitro derivative 78, whereas methylation with methyl iodide or methyl sulfate afforded the corresponding 6-pyridinium methiodide 79 or methosulfate 80, respectively (Scheme 29). The pyridinium salt 80 was submitted to oxidation with potassium hexacyanoferrate and provided 7-oxo-6,7-dihydro derivative 81 or, by reaction of pyridinium salt 79 with phenylmagnesium bromide, the 7-phenyl-6,7-dihydro derivative 82. Nucleophilic substitution of the methiodide 79 with potassium cyanide resulted in the formation of 9-cyano-6,9-dihydroderivative 83, which can be oxidized by iodine to 9-cyano-l,2,5-selenadiazolo [3,4-/]quinoline methiodide 84. All the reactions proceeded in moderate yields (81IJC648). 

In a dry 3-1. three-necked, round-bottomed flask fitted with an efficient reflux condenser, a stirrer, a Y-tube holding a 1-1. and a 250-ml. addition funnel, and protected from moisture by calcium chloride tubes is placed 5.76 g. (0.237 mole) of magnesium turnings barely covered by anhydrous ether, p -Bromotoluene (40 drops) and ethyl bromide (20 drops) are added, and the reaction starts immediately. />-Bromotoluene (35.0 g., 0.205 mole) in 200 ml. of anhydrous ether is added at such a rate that reflux is maintained. To the resultant solution of />-methyl-phenylmagnesium bromide is added, over a 1-hour period, a solution of 25.4 g. (0.200 mole) of dichloroacetone in 200 ml. of anhydrous ether. 

The bromo derivative 16 reacts with phenylmagnesium bromide in diethyl ether, followed by workup with 5% aqueous hydrobromic acid, to give 2-methyl-4,5-diphenyl-2//-2,3-benzo-diazepin-l(5//)-one (17) in 55% yield.137 No further details were reported. 

The lower diastereoselectivity found with aldehyde 15 (R = CH3) can be explained by the steric influence of the two methyl substituents in close vicinity to the stereogenic center, which probably diminishes the ability of the ether oxygen to coordinate. In contrast, a significant difference in the diastereoselectivity was found in the additions of phenyllithium and phenylmagnesium bromide to isopropylidene glyceraldehyde (17)58 (see also Section 1.3.1.3.6.). Presumably the diastereo-sclcctivity of the phenyllithium addition is determined by the ratio of chelation-controlled to nonchelation-controlled attack of the nucleophile, whereas in the case of phenylmagnesium bromide additional chelation with the / -ether oxygen may occur. Formation of the -chelate 19 stabilizes the Felkin-Anh transition state and therefore increases the proportion of the anZz -diastereomeric addition product. 

R)- and (,S )-1.1,2-Triphenyl-l,2-ethancdiol which are reliable and useful chiral auxiliary groups (see Section 1.3.4.2.2.3.) also perform ami-sclcctive aldol additions with remarkable induced stereoselectivity72. The (/7)-diastercomer, readily available from (7 )-methyl mandelate (2-hy-droxy-2-phcnylaeetate) and phenylmagnesium bromide in a 71 % yield, is esterified to give the chiral propanoate which is converted into the O-silyl protected ester by deprotonation, silylation, and subsequent hydrolysis. When the protected ester is deprotonated with lithium cyclohexyliso-propylamide, transmetalated by the addition of dichloro(dicyclopentadienyl)zirconium, and finally reacted with aldehydes, predominantly twm -diastereomers 15 result. For different aldehydes, the ratio of 15 to the total amount of the syn-diastereomers is between 88 12 and 98 2 while the chemical yields are 71 -90%. Furthermore, high induced stereoselectivity is obtained the diastereomeric ratios of ami-15/anti-16 arc between 95 5 and >98 2. 

Triphenylcarbinol has been obtained by the reaction between phenylmagnesium bromide and benzophenone,1 methyl benzoate, or phosgene 8 by action of phenylsodium upon benzophenone, benzoyl chloride, ethyl chlorocarbonate, or ethyl benzoate 4 by hydrolysis of triphenylchloromethane 5 and by oxidation of tri-phenylmethane.6... 

R)-(+)-1,1,2-Triphenyl-1,2-ethanediol is available from methyl3 and ethyl4 (R)-(-)-mandelate by treatment with phenylmagnesium bromide. The synthesis of (R)-(+)-2-hydroxy-1,2,2-triphenylethyl acetate [(R)-HYTRA] has been reported previously by the submitters.5 6 (S)-(-)-2-Hydroxy-1,2,2-triphenylethyl acetate is available according to this procedure starting from the enantiomeric methyl (S)-(+)-mandelate or (S)-(+)-... 

The above procedure is essentially that of Ullmann and Bleier.2 2-Aminobenzophenone has also been prepared by reduction of 2-nitrobenzophenone,3 by the Hofmann reaction of the amide of o-benzoylbenzoic acid with sodium hypobromite,4 by the action of an excess of benzoyl chloride on aniline at 220°,6 and by hydrolysis of the acetyl derivative which is obtained by the action of phenylmagnesium bromide on 2-methyl-3,l,4-benzoxaz-4-one (from anthranilic acid and acetic anhydride).6 Various methods for the preparation of 2-aminobenzophenones have been summarized critically by Simpson, Atkinson, Schofield, and Stephenson.7... 

High stereoselectivities (94-100 %) are attained in the reduction of aromatic ketones by use of a new chiral borane complex with (S)-2-amino-3-methyl-l,l-diphenylbutan-l-ol,(S-68) readily prepared in two steps from (S)-valine, in an experimentally convenient procedure961. (S)-Valine methyl ester hydrochloride was converted with excess of phenylmagnesium bromide into (S-68). The same treatment of (R)-valine gave (R-68). In a typical asymmetric reduction the reagent, prepared from (S-68) and borane, and the ketone (69) in tetrahydrofuran were kept at 30 °C for some hours. The corresponding alcohols were obtained in high optical purity. (S-68) could be recovered to more than 80% without racemization 96). 

Three hundred thirty-six milliliters (312 g., 3.00 moles) of methyl borate is distilled directly into the 500-ml. dropping funnel shortly before starting the reaction (Note 4). One liter (511 g., 3.0 moles) of a 34/ ethereal solution of phenylmagnesium bromide is pressure-transferred with dry nitrogen into the 1-1. 

Mallinckrodt analytical reagent grade ether, dried over sodium, was used. The methyl borate was the commercial product of American Potash and Chemical Corporation containing 99% ester as received. The phenylmagnesium bromide was purchased as a 3.0M solution in ether from Arapahoe Special Products, Inc., Boulder, Colorado. 

Transition metal compounds with covalent carbon-metal bonds include organo-zinc, organo-cadmium, and organo-mercury compounds. Carbon-13 shifts of the methyl derivatives (Table 4.71) indicate a heavy atom deshielding. Diphenylmercury displays carbon shifts similar to those of phenyllithium and phenylmagnesium bromide (Table 4.53). 

Treatment of l-methyl-2-piperidone with phenylmagnesium bromide and subsequent reaction with acetic anhydride and then water gave the acetate 21 in small yield.139 This indicates that the salt of the carbinolamine form is an intermediate which, on liberation, affords the cyclic enamine in the five- and six-membered series, for steric reasons. 

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