Trimethylsilyldiazomethane lithiated

On the other hand, 3,5-disubstituted [l,2,4]diazaphosphole 29 could be obtained from the reaction of tri-ferf-butylphenylphosphaethyne (25) with freshly prepared lithiated trimethylsilyldiazomethane (30) and subsequent treatment of the initially formed diazaphospholide ion (31) with trifluoroacetic acid (Scheme 9) [33],... 

Podlech, I 1998. Trimethylsilyldiazomethane (TMS-CHNj) and lithiated trimethylsilydiazomethane—versatile substitutes for diazomethane. JPrafcf Chem. 340, 679-682. 

The trimethylsilylynolate is prepared on treatment of trimethylsilyldiazomethane (23) with BuLi followed by exposure to carbon monoxide. The mechanism is explained by the fact that the lithiated silyldiazomethane (24) adds to carbon monoxide to give the labile a-diazoacyllithium 25, which rearranges to the ynolate 27 via the ketene intermediate 26 (equation 8). ... 

Trimethylsilyldiazomethane (96), prepared in excellent yield from chloromethyltrimethylsilane, is now commercially available (Petrarch). Trimethylsilyldiazomethane is readily lithiated and alkylated (equation 40).Synthetic applications of the resultant silyldiazoalkanes (97) have not yet been extensively explored. These might, for instance, react smoothly with acid chlorides to give diazoketones (see Section 1.4.6.1). 

Benzofurans. A method for the preparation of benzofurans from o-hydroxy phenones involves conversion to the alkynes (deoxygenation with one-carbon insertion) by reaction with lithiated trimethylsilyldiazomethane, and treatment of the products with TBAF. 

Alkynes. Deoxygenative homologation of ketones is accomplished simply by treatment with lithiated trimethylsilyldiazomethane. 

Addition of lithiated trimethylsilyldiazomethane to aldehydes provided adduct 103 which was shown through in situ IR measurements and quenching experiments to be in equilibrium with the 1,3-Brook-rearranged carbanion 104. Addition of methanol or methyl iodide provided 105 and 106, respectively. Stereocontrolled hydride shift upon formation of the rhodium-stabilized carbenoid provided (2)-selective formation of silyl enol ethers 107 and 108. ... 

Preparative Methods prepared in situ by lithiation of trimethylsi-lyldiazomethane using n-butyllithium prepared in situ by lithiation of trimethylsilyldiazomethane (TMSCHN2) using butyllithium, lithium diisopopylamide (LDA), or lithium 2,2,6,6-tetramethylpiperidide (LTMP). The lithium salt is easily converted to the corresponding magnesium bromide salt (eq 1). 

Metalation of diazomethane produces the lithiated compound 11a having a structure similar to 10a except for the C-Li bond in particular, the C-N and N-N bonds do not change much on metalation. Moreover, since there is no lone pair on the central nitrogen, the lithium does not bridge between C and N. In 11b the CN bond is computed to be much shorter and the NN bond much longer than in 11a, The isomeric lithium derivative 11b is computed to be more stable than 11a, The interconversion of the two isomers probably occurs via the dimers that are substantially more stable than the monomers. A crystal structure that contains the related lithiated trimethylsilyldiazomethane, (CH3)3SiCHN2, was interpreted with the help of model calculations. ... 

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