Diels-Alder Reaction

Abstract

The chemists have long believed that the trivalent boron atom with its empty p orbital should behave in a fashion to that of the traditional organic electronwithdrawing group [1]. This idea is attractive when applied to the activation of Diels-Alder dienophiles, because the intermediate boron compounds can be transformed to an array of different functional moieties, none of which can usually be obtained by a direct Diels-Alder reaction. Matteson [2] and Evans [3] have reported the reactions of vinylboronic esters with dienes under strenuous reaction conditions but with low yields of the products. Similarly, vinyldichloroborane gives low yield [4] on reaction with cyclopentadiene.