Synthesis and reactivity of α-silylated carbocations

INOR 779

Ching-Wen Chiu, cchiu@mail.chem.tamu.edu and François P. Gabbaï. Department of Chemistry, Texas A & M University, 3255 TAMU, College Station, TX 77843-3255
Silyl substituents are typically considered to destabilize α-carbocations. Hoping to harness this destabilizing effect for the design of highly electrophilic molecules, we have now turned our attention to the synthesis and characterization of cationic species featuring a silyl group directly linked to a carbocationic center. The 9-(trimethylsilyl)acridinium, which can be regarded as a silylated methylium compound, was prepared and studied. The result shows this cation quickly react with fluoride to afford 9-(fluorodimethylsilyl)-9-methyl-acridane. Electrochemical studies suggest that 9-(trimethylsilyl)acridinium can be reduced by one electron to afford a stable neutral radical.