Lithiomethyl phenyl

Alternatively addition of lithiomethyl phenyl selenide to cyclobutanones followed by treatment with iodomethane and base is reported to yield the spiroepoxide.222... 

Lithiomethylphenyl tellurium, which is best prepared from bis[phcnyltelluro]methane and a lithioalkane, reacts with carbonyl compounds and alkyl halides. The greenish-yellow solution of lithiomethyl phenyl tellurium in THF is stable for at least 24 h when kept at 0° under an inert atmosphere2. 

A reaction sequence starting with bis[phenyltelluro]mcthane leads to the insertion of a methylene group into the carbon-halogen bond of an alkyl halide. The bis[phenyltelluro] methane is reacted with butyl lithium to yield lithiomethyl phenyl telluride, which combines with an alkyl halide. The resulting alkylmethyl phenyl tellurium is converted to the tellurium dihalide, which in turn decomposes to an alkylmethyl halide when kept under vacuum at 250 6 or heated in DMF in the presence of a sodium halide at 100°7. 

If the alkyl halide is reacted with lithiomethyl phenyl tellurium in place of benzenetellurola-te, the alkyl halide is converted to an alkyl ether with the carbon chain lengthened by a methylene group. 

Alkyl phenyl telluriums react with AT-chloro-A-sodio-4-methylbenzenesulfonamide in refluxing THF to yield terminal olefins from prim, alkyl groups and a mixture of 1 -alkenes and 2-alkenes from sec. alkyl groups. Diorgano tellurium imides were postulated as intermediates. Considering the synthesis of the alkyl phenyl tellurium from an alkyl halide and benzenetellurolate, the overall reaction is the conversion of an alkyl halide to an olefin. Starting with lithiomethyl phenyl tellurium and an alkyl halide, the resulting olefin will have one carbon atom more than the alkyl halide. ... 

Polymetalated systems of this type without phenyl substitution at the lithiated carbon centre are only accessible when solutions of LiCioHg (144a) or LiDBB (145) in THF instead of a suspension of metallic lithium in THF are reacted with bis(phenylthiomethyl)silanes of type 155. In our group, variously substituted bis(lithiomethyl)silanes 117a, 156b-e and 101 were synthesized by reductive cleavage of the carbon-sulphur bond with LiCioHg... 

A flexible means of access to functionalized supports for solid-phase synthesis is based on metallated, cross-linked polystyrene, which reacts smoothly with a wide range of electrophiles. Cross-linked polystyrene can be lithiated directly by treatment with n-butyllithium and TMEDA in cyclohexane at 60-70 °C [1-3] to yield a product containing mainly meta- and para-Iithiated phenyl groups [4], Metallation of noncross-linked polystyrene with potassium ferf-amylate/3-(lithiomethyl)heptane has also been reported [5], The latter type of base can, unlike butyllithium/TMEDA [6], also lead to benzylic metallation [7]. The C-Iithiation of more acidic arenes or heteroar-enes, such as imidazoles [8], thiophenes [9], and furans [9], has also been performed on insoluble supports (Figure 4.1). These reactions proceed, like those in solution, with high regioselectivity. 

When 6-methylphenanthridine is allowed to react with phenyl-lithium in ether, side-chain metalation takes place exclusively.340 The lithiomethyl derivative so obtained forms l,2-bis(6-phenanthri-dyl)ethane in good yield on treatment with oxygen.341... 

Thiazole and benzothiazole exchange the C-2 hydrogen for lithium or magnesium when treated with an ethereal solution of phenyl- or butyl-lithium at -60 °C or ethylmagnesium bromide at 0 °C then at 25 °C (Scheme 31). When the 2-position of thiazole is occupied by a methyl group, the reaction of butyl-lithium at low temperature (-100 °C) affords three independent lithio salts (54, 55 and 56 Scheme 32) in the approximate ratio 52 3 45. As the temperature is increased, the 2-lithiomethyl derivative (54), which is less stable than the 5-lithio isomer (56), decomposes up to +5 °C at which point it has almost entirely disappeared. 

The addition of lithium diethyl phosphite to the imines (201) from (/ )-(—)- -amino-l-phenyl-2-methoxyethane gave mixtures of (202) and (203) in the ratios of >110 1 to 7 1, but mostly around 50 1. The sequence was completed by hydrogenolytic removal of the benzylic group, when the product (1-aminoalkyl)-phosphonic diesters had e.e.s of 96-99%. The diastereoisomeric ratios within (205), obtained from the chiral sulfoxides (204) and diethyl (lithiomethyl)phos-phonate, varied from 4.9 1 (R = PhCH=CH) to 9.2 1 (R = 2-thienyl), but the ratio also depended, to some extent, on the nature of the phosphonate alkyl group. ... 

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