H. Mayr et al., COMPARISON OF THE NUCLEOPHILICITIES OF ALKYNES AND ALKENES - QUANTITATIVE-DETERMINATION OF THE NUCLEOPHILICITIES OF ALKYNES TOWARD CARBENIUM IONS, Chemische Berichte, 127(3), 1994, pp. 525-531
Relative reactivities of alkenes and alkynes toward diarylmethyl catio
ns have been determined by direct rate measurements and by competition
experiments in dichloromethane. At -70 degrees C alkynes are found to
be one to two orders of magnitude less reactive than analogously subs
tituted alkenes (e.g. phenylacetylene/styrene), but the reactivity dif
ference reduces strongly as the temperature is raised. The stereochemi
stry of the vinyl chlorides produced by addition of benzhydryl chlorid
es to alkynes is characterized.