18001-52-0Relevant academic research and scientific papers
The sila-Pummerer rearrangement of 3,3-dimethyl-3-silathiane S-oxide
Kirpichenko, Svetlana V.,Suslova, Elena N.,Albanov, Alexandr I.,Shainyan, Bagrat A.
, p. 185 - 188 (1999)
The thermal conversion of sulfoxide 1 into the O-silylated cyclic O,S- acetal (2) is the first example of the sila-Pummerer rearrangement of cyclic organosilicon sulfoxides leading to ring expansion. The kinetics of the rearrangement are studied and thermodynamic parameters are determined. The results are in compliance with mechanism involving a pentacoordinated silicon atom.
Comparative reactivity of substituted 1,3- and 1,4-thiasilinane S-oxides in the sila-Pummerer rearrangement and inversion of the thiocarbonyl group
Suslova,Ushakov,Shainyan
, p. 253 - 263 (2007)
The thermal sila-Pummerer rearrangement of diastereomeric 2,3,3-trimethyl-1,3-thiasilinane S-oxides was studied. Introduction of the methyl group in the 2 position of 3,3-trimethyl-3-thiasilinane S-oxide slows down the rearrangement. When heated in CCl4, the trans isomer (2-Meeq, SOeq) converts into the cis isomer (2-Me eq, SOax) which rapidly rearranges into 2,2,7-trimethyl-1,6,2-oxathiasilepane. On the contrary, the isomeric 2,4,4-trimethyl-1,4-thiasilinane S-oxide is thermally stable up to 160°C in DMSO. The inversion at the sulfur atom in 2,3,3-trimethyl-1,3-thiasilinane S-oxides and 2,4,4-trimethyl-1,4-thiasilinane S-oxides under the action of triethyloxonium tetrafluoroborate was studied. The trans isomer of 2,3,3-trimethyl-1,3-thiasilinane S-oxide (2-Meeq, SOeq) forms with Et3O+BF 4 - a salt which decomposes in two ways. The first involves recovery of the starting sulfoxide due to Sn2 substitution at the carbon atom of the ethoxy group, and the second, convertion into the cis isomer (2-Meeq, SOax) which rearranges into 2,2,7-trimethyl-1,6,2-oxathiasilepane. Under the same conditions, the cis isomer of 2,3,3-trimethyl-1,3-thiasilinane S-oxide (2-Meeq, SOeq) decomposes to form siloxanes. trans-2,4,4-Trimethyl-4-thiasilinane S-oxide (2-Meeq, SO eq) under the action of Et3O+BF 4 - convers into the cis isomer (2-Meeq, SOax). The B3LYP/6-311G(d,p) theoretical analysis showed that the thermal inversion at the sulfur atom in the compounds studied has a high energy barrier.
