Two types of intramolecular homolytic substitution reactions at group XIV atoms: unusual radical 1,4-Sn shifts from Si to C and carbonylative SHi reaction at Si.
4-[(Trimethylstannyl)diphenylsilyl]butanoyl radical, arising from the corresponding 3-(stannylsilyl)propyl radical and CO, undergoes an SHi reaction at Si with extrusion of trimethyltin radical to give silacyclopentanone. The parent 3-(stannylsilyl)propyl radical was also found to isomerize to (3-stannylpropyl)silyl radical via a 1,4-Sn shift from Si to C with a rate constant of 9.3 x 10(4) s-1 at 80 degrees C. Ab initio and DFT MO calculations support a front-side attack mechanism.
Studer
Armido
A
Fachbereich Chemie, Universität Marburg, Hans-Meerwein-Strasse, D-35032 Marburg, Germany. studer@Mailer.Uni-Marburg.de
Amrein
Stephan
S
Matsubara
Hiroshi
H
Schiesser
Carl H
CH
Doi
Takashi
T
Kawamura
Tomonori
T
Fukuyama
Takahide
T
Ryu
Ilhyong
I