Assessing the Brønsted Basicity of Diaminoboryl Anions: Reactivity toward Methylated Benzenes and Dihydrogen

Abstract

Treatment of toluene or p-xylene with diaminoboryllithium results in consecutive reactions, involving boryl-anion-mediated deprotonation at the benzylic position followed by nucleophilic substitution at the boron center, producing benzylborane species and LiH. Diaminoboryllithium also cleaves H2 heterolytically affording diaminohydroborane and LiH, while the reaction of lithium diaminoboryl(bromo)cuprate with H2 takes place accompanied by reduction of Cu(I) to give diaminohydroborane, LiH, and Cu(0).