Phenyldimethylsilyl lithium

The strict geometrical requirements for elimination can be put to further use, as illustrated by elegant procedures for the geometrical isomerization of alkenes. Trimethylsilyl potassium (10) and phenyldimethylsilyl lithium (11) both effect smooth conversion of oxiranes into alkenes, nucleophilic ring opening being followed by bond rotation and spontaneous syn fi-elimination ... 

Dichloro-1-silacyclopentane reacts with phenyldimethylsilyl lithium to yield the disilyl derivative, which can then be halogenated with HC1/A1C13. 

A solution of hex-l-yne (4.5 mmol) in THF (1ml) was added slowly to lithium bis(phenyldimethylsilyl)cuprate (Chapter 8) (5 mmol, based on CuCN) at 0°C, and the mixture was stirred for 15min at 0°C. Saturated ammonium chloride solution (1 ml) was added, and stirring was continued for 5 min at 0°C. Light petroleum was then added, and the organic layer was washed with ammonium chloride solution, and dried. Concentration and chromatographic purification on silica gel gave the vinylsilane (4.23 mmol, 94%). 

Lewis acids, 15,72,106,108-11,112,116,128 Lithiation, 84 reductive, 68 o-Lithiation, 40 a-Lithiosilanes, 65, 68 o-Lithiosilyl enol ethers, 77 a-Lithiovinylsilanes, 69 Lithium bis(phenyldimethylsilyl)cuprate, 8,53... 

The conjugate addition of lithium bis(phenyldimethylsilyl)cuprates to tt./t-unsaUi rated esters forms enolates, which readily react with aldehydes to give 2-substituted 3-silyl esters (equation 129)509. The products are useful as intermediates in the synthesis of allylsilanes and natural products. Yields of this reaction may be significantly increased by... 

Fleming has generated enolates by conjugate addition of lithium bis(phenyldimethylsilyl)cuprate to a,p-unsaturated esters. The intermediate (Z)-enolates undergo stereoselective aldol addition, providing adducts having three contiguous stereocenters one example of this process is seen in equation (20). - ... 

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