74502-29-7Relevant academic research and scientific papers
Perturbations by phenyl on the 1,5-hydrogen shift in 1,3(Z)-pentadiene. Another chameleonic transition region?
Doering, William Von E.,Keliher, Edmund J.,Zhao, Xin
, p. 14206 - 14216 (2007/10/03)
The acyclic 1,5-dienyl hydrogen shift is accelerated by radical-stabilizing phenyl substituents without regard to the type of position occupied in the 1,3(Z)-pentadiene system. 1-Phenyl-5-p-tolyl-1,3(Z)-pentadiene has a corrected energy of activation 5.8 kcal mol-1 lower than that of the parent, while the 2-and 3-phenyl analogues, examined in cyclic systems specifically designed to obviate the otherwise general need for a thermochemical correction to the immediately precursory s-cis conformation, reveal stabilizing effects of 3.6 and 3.4 kcal mol-1, respectively. These relatively small effects are consistent with a chameleonic conceptual scheme for the transition region.
COMPLEXES OF TRANSITION METALS IN THE CHEMISTRY OF CONJUGATED SYSTEMS. I. CATALYTIC ADDITION OF ORGANOMAGNESIUM AND ORGANOLITHIUM COMPOUNDS TO ENYNES AND THEIR DERIVATIVES
Zubritskii, L. M.,Fomina, T. N.,Bal'yan, Kh. V.
, p. 63 - 71 (2007/10/02)
Hydrocarbons with a conjugated system of double and triple bonds are capable of catalytic addition of arylmagnesium halides and aryllithiums at the triple bond in the presence of the salts and complexes of transition metals of group VIII.The β-diketonate complexes of Ni(II) and Fe(III) have the greatest activity.In the case of aryllithiums uncatalyzed addition reactions occur as well.Under the same conditions aliphatic Grignard reagents and alkyllithiums give a complex mixture of addition, reduction and oligomerizatin products.The direction of addition is determined solely by the character of substitution in the enyne system.The product yields are also determined by the nature of the metal and of the ligands in the catalyst and by the character of the organomagnesium and organolithium compound.The effect of polar and steric factors of the substituents at the triple bond in the alkyl, aryl, and trialkylsilyl series leads to a change in the direction of coordination and to the formation of the products from addition at the double bond.
