The question of C- vs. O-silylation of ketenes: electrophilic triethylsilylation of diphenylketene.

Research paper by G K Surya GK Prakash, Chulsung C Bae, Golam G Rasul, George A GA Olah

Indexed on: 21 Apr '05Published on: 21 Apr '05Published in: PNAS


Electrophilic triethylsilylation of diphenylketene leads to exclusive C-silylation giving the diphenyl(triethylsilyl)acetyl cation in the solution phase even though density functional theory calculations at the B3LYP/6-311+G* level indicate that the O-silylation of diphenylketene is preferred over C-silylation by 5.4 kcal/mol in the gas phase. On the other hand, in the case of the parent ketene, similar density functional theory calculations show that C-silylation is preferred over O-silylation by 8.2 kcal/mol.