REACTION BETWEEN (CHLORODIMESITYLSILYL)DIARYLGERMANES AND TERT-BUTYLLITHIUM IN THF - FORMATION OF NEW GERMYLLITHIUM COMPOUNDS

Treatment of (chlorodimesitylsilyl)diarylgermanes (1, Ar = 2,4,6-trimethylphenyl = mesityl = Mes; 2, Ar = 2,4,6-triisopropylphenyl) with excess tert-butyllithium in THF followed by quenching the reaction mixture with methanol gave (dimesitylsilyl)diarylgermanes (3, Ar = Mes; Ar = 2,4,6-triisopropylphenyl). Surprisingly, when either reaction mixture was quenched with methanol-d4, the corresponding (dimesitylsilyl) diaryldeuteriogermanes (3a, Ar = Mes; 4a, Ar = 2,4,6-triisopropylphenyl) were formed. The germyllithium compound Ar2GeLiSiHMes2 has been proposed as an intermediate. The germyllithium (Ar = Mes) was also trapped with other electrophiles, e.g. methyl iodide, chlorotrimethylsilane, and benzyl bromide, to give Mes2GeESiHMes2 (5, E = Me; 6, E = SiMe3; 7, E = Br). Possible mechanisms for the formation of these compounds are also discussed.