Interrogating Redox and Lewis Base Activations of Aminoboranes

Abstract

For decades, aminoboranes were only used in amination reactions stemming from the difficulty in activating the enthalpically strong B–N bond with anything other than ionic Lewis bases (e.g., nBuLi, KOtBu, etc.). Herein, we show that the coordination of neutral Lewis bases to aminoboranes is endergonic but observable, thereby suggesting catalytic relevance. We also leverage electro- and photochemical exper-iments to show that aminoboranes can be activated via electrochemical oxidation and exhibit photochemical quenching of the excited state of commercially available fluorophores. The results presented herein represent critical insights needed for the future discovery of bona fide aminoboration reactions under mild reaction conditions.