197958-33-1Relevant academic research and scientific papers
The Heterogeneous Catalytic Hydrogenation of Cumulated Allene-cyclopropanes: 1-(2'-Methylpropenylidene)-2-phenylcyclopropane.
Cromble, Leslie,Fernando, Candida E. C.
, p. 1519 - 1537 (2007/10/03)
The unsymmetrical title compound 2 having phenyl as an activating substituent was hydrogenated in heterogeneous solution phase using supported platinum and palladium as well as Raney nickel catalysts. Data are presented graphically using 'snapshot analysi
Conjugative interaction in styrenes
Von Doering,Benkhoff, Johannes,Carleton, Peter Smart,Pagnotta, Marco
, p. 10947 - 10955 (2007/10/03)
Conjugative interactions of the carbon-carbon double bond are fundamental in organic chemistry. In this work, equilibria are established among conjugated and unconjugated isomers of two β-substituted styrenes, 1-phenylbut-1-ene and 1-phenyl-3-methylbut-1-ene, and one α,β-disubstituted styrene, 2-phenyl-5-methylhex-2-ene, over a range of temperatures (the van't Hoff method) in hexamethylphosphoric triamide and potassium tert-butoxide. From the trans styrenes of the first two sets, an enthalpy of conjugative interaction of phenyl vis-a-vis alkyl (ΔΔH(ConjInter/Alk)) = -2.5 ± 0.2 kcal/mol [-5.1 kcal/mol defined as phenyl vis-a-vis hydrogen (ΔΔH(ConjInter/H))] is observed, while the cis styrenes reveal an attenuated ΔΔH(ConjInter/Alk) of -1.1 kcal/mol (ΔΔH(ConjInter/H)) = -2.7 kcal/ mol). The α-methyl group in the third set also leads to a reduced conjugative interaction. Entropy plays an important role in determining positions of equilibrium. Free energies of conjugation are reported for several sterically hindered o-methyl-substituted styrenes.
