2808-75-5Relevant articles and documents
Hammond,Nevitt
, p. 4121 (1954)
Six- vs seven-membered ring formation from the 1- bicyclo[4.1.0]heptanylmethyl radical: Synthetic and ab initio studies
Kantorowski, Eric J.,Eisenberg, Shawn W. E.,Fink, William H.,Kurth, Mark J.
, p. 570 - 580 (2007/10/03)
The viability of utilizing 1-bicyclo[4.1.0]heptanylmethyl radical (3) to serve as a progenitor of seven-membered carbocycles was examined. Rate constants for the rearrangement of this radical to 3-methylenecycloheptyl radical (4) and 2-methylenecyclohexyl-1-methyl radical (6) were measured using the competition method of 3 with thiophenol over the temperature range of -75 to 59 °C. Arrhenius functions were calculated for the conversions of 3 to 4 and 3 to 6 and found to be log(k/s-1) = (12.38 ± 0.20) - (5.63 ± 0.23)/θ and log(k/s-1) = (11.54 ± 0.32) - (5.26 ± 0.37)/θ, respectively. The rate constants for these conversions at 25 °C are 1.86 x 108 s-1 and 5.11 x 107 s-1, respectively. Hence, the seven-membered ring-expanded carbocycle is formed 3.6 times faster at 25 °C than the nonexpanded species. This suggests that the 1-bicyclo[4.1.0]heptanylmethyl radical system may be synthetically useful in seven-membered ring-forming methodology. Preliminary theoretical examination of this radical system qualitatively predicted the experimentally determined energies of activation: PMP4/6-31G*//HF/6-31G*ΔE(a) (3 → 6 - 3 → 4) = 3.0 kcal/mol with zero point energy correction. The HF/6-31G* optimized reaction coordinate stationary points suggest cyclopropyl substituent eclipsing interactions play an important role in determining the kinetic outcome of these rearrangements.
Regio- and stereo-selective coupling reactions of cyclo-1,3-dienes catalysed by titanium aryloxide compounds
Waratuke, Steven A.,Johnson, Eric S.,Thorn, Matthew G.,Fanwick, Phillip E.,Rothwell, Ian P.
, p. 2617 - 2618 (2007/10/03)
Highly selective non-Diels-Alder dimerization of cyclohexa-1,3-diene and cross-coupling of either cyclohexa-1,3-diene or cycloocta-1,3-diene with α-alkenes is catalysed by titanium aryloxide compounds.