Absoluterateconstants were determined for the additions of 5 5-X-substituted ArCCl (X=CF3, Cl, H, CH3, CH3O) to tetramethylethylene, trimethylethylene, trans-pentene, and 1-hexene; good Hammett correlations were obtained with ϱ = +1.4 – 1.6.
reactions of phenylchlorocarbene and related carbenes with alkenes are summarized and systematized. The experiments described provide the basis for a detailed examination of carbenic reactivity-selectivity principles. The results of studies on the influence of temperature on the absolute rate constants for carbene reactions are consistent with the existence of transient carbene/alkene intermediates.
申请人:SHELL INTERNATIONALE RESEARCH
MAATSCHAPPIJ B.V.
公开号:EP0432818A2
公开(公告)日:1991-06-19
Process for ring opening compounds of the formula
in which R¹ is heteroaryl or aryl, R² is a leaving group, R³, R⁴, R⁵ and R⁶ are independently selected from hydrogen, alkyl, aralkyl, aryl, heteroaryl and alkenyl, provided that at least one of the groups R³ to R⁶ is other than hydrogen, by breaking the bond joining the carbon atom attached to R³ and the carbon atom attached to R⁶ in organic solution using silica,giving useful diene or allyl derivatives, certain of which are novel.