Pyrolysis of 9-methylenespiro[3.5]nona-5,7-diene: a route to benzo-2-hexene-1,6-diyl, a putative intermediate in the retro-Diels-Alder reaction of tetralin
Pyrolysis of 9-methylenespiro[3.5]nona-5,7-diene: a route to benzo-2-hexene-1,6-diyl, a putative intermediate in the retro-Diels-Alder reaction of tetralin
Entropic Intermediates and Hidden Rate-Limiting Steps in Seemingly Concerted Cycloadditions. Observation, Prediction, and Origin of an Isotope Effect on Recrossing
作者:Ollie M. Gonzalez-James、Eugene E. Kwan、Daniel A. Singleton
DOI:10.1021/ja208779k
日期:2012.2.1
An unusual intramolecular kinetic isotope effect (KIE) in the reaction of dichloroketene with cis-2-butene does not fit with a simple asynchronous cycloaddition transition state, but it can be predicted from trajectory studies on a bifurcating energy surface. The origin of the KIE is related to a high propensity for transition state recrossing in this system, with heavier masses recrossing less. The