The Influence of Solvent, Temperature, and the Types of Olefins to the Distribution Reaction of Olefins with Borane

Abstract

The influence of solvent, temperature, and the types of olefins on the equilibration reaction of a mixture of norbornylboranes were examined. In heptane or neat, the distribution rate was much smaller than that in THF-solution and the content of di-exo-norbornylborane under the norbornene: borane ratio of 2 was less favorable (in haptane, 47-50%; neat, 40-43%)than that of THF solution (55-57%). At higher temperatures, the distribution rate was considerably accelerated (the rate under THF-reflux was 10² times faster than that at room temperature); but the equilibrium distribution itself did not change significantly. The yield of dialkylborane in the redistribution reaction (R₃B+BH₃→)was remarkably influenced by the types of- olefins. It was possible to obtain an almost quantitative yield of R₂BH using 1-