The question of C- vs. O-silylation of ketenes: electrophilic triethylsilylation of diphenylketene.
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.
Prakash
G K Surya
GK
Loker Hydrocarbon Research Institute and Department of Chemistry, University of Southern California, University Park, Los Angeles, CA 90089-1661, USA.
Bae
Chulsung
C
Rasul
Golam
G
Olah
George A
GA