posted on 2022-12-12, 22:04authored byAlexander
A. Braddock, Grace E. Lee, Emmanuel A. Theodorakis, Erik A. Romero
Since their discovery, aminoboranes (R2N–BR2) have been applied as intermediates in chemical hydrogen
storage devices, asymmetric catalysts, semiconductors, and amination/borylation
reagents. Recently, chemists have extended their application to reagents
for difunctionalization reactions, wherein the N–B bond is
cleaved and the amine and boronic ester fragments are distributed
across an organic molecule. Generally, harsh conditions or loss of
the borane/amine fragment as waste is required to enable reactivity
of the enthalpically stable partial sp2-hybridized N–B bond. We sought to show that mild avenues
also exist to disrupt the dative N–B π-bond. Herein,
we survey the coordinative capabilities of neutral Lewis bases to
(amino)pinacolboranes and whether the partial sp2-hybridized N–B bond can be oxidized electro- or photochemically
in analogous fashion to C=C bonds. The results of these studies are
strongly in the affirmative and should guide the thought processes
of organic chemists when designing new reactions using aminoboranes.