36332-23-7Relevant academic research and scientific papers
Thermally-induced 1,2-shifts to convert olefins to carbenes: Does silicon do it? if so, why not carbon?
Barton, Thomas J.,Lin, Jibing,Ijadi-Maghsoodi, Sina,Power, Martin D.,Zhang, Xianping,Ma, Zhongxin,Shimizu, Hideaki,Gordon, Mark S.
, p. 11695 - 11703 (1995)
Thermal isomerization of olefins to carbenes via a 1,2-silyl shift was examined by both experiment and theory. No evidence of this rearrangement was found for acyclic vinylsilanes, nor could electronic assistance by silicon be identified in cis, trans isomerizations. Serendipitous synthesis of a 2,4-dimethylene-1,3-disilacyclobutane allowed a kinetic examination of its gas-phase, thermal ring expansion to a 2-methylene-1,3-disilacyclopentene. The Arrhenius parameters (log A = 12.48, Eact = 54.09 kcal/mol) are the first to be reported for an olefin-to-carbene rearrangement. The analogous all-carbon system failed to ring expand. Ab initio calculations revealed that this was opposite to any predictions which would be made from ring strain considerations. Calculations showed that for silyl migration the transition state was late and was actually the carbene, while for carbon migration the TS was early and considerably higher in energy than the resulting carbene. The 2-methylene-1-silacyclobutane rearrangement (ref 5) was reexamined to find that reversible ring opening to a 1,4-diradical occurred at temperatures below those required to ring expand via a carbene TS.
The Effect of Long-range Circumannular Non-bonding Orbital Interaction on the Inversion of Groups on Nitrogen in 2,2,4,4-Tetramethyl-3-imino-1-cyclobutanones
Naik, Arati,Ferro, Michelle,Worman, James
, p. 1059 - 1060 (2007/10/03)
matrix presented The free energy of activation, ΔG*, for nitrogen inversion was calculated from the coalescence temperature for the methyl signals obtained via variable temperature NMR for a series of imino derivatives of the title compounds. There was a
