Convergent synthesis of bicyclic boronates via a cascade regioselective Suzuki-Miyaura/cyclisation protocol

Bicyclic boronates have recently emerged as promising candidates to invoke targeted biomolecular interactions, given their selectivity for specific functionalities. Despite this, the general stability of the C-B bond in vivo, for such heterocycles, remains an intractable challenge that can often preclude their utility in drug discovery. To address this challenge, de novo strategies that allow expedient access to strategically substituted boronates, that enable modulation of the C-B bond are urgently required. Herein we disclose an operationally simple, regioselective cross-coupling/cyclisation reaction of easily accessible vicinal boronic esters with 2-halophenols to rapidly forge 3-substituted bicyclic boronates. The utility of the platform was demonstrated via expedient access to Xeruborbactam derivatives, chemoselective manipulation of formed products and the convergent approach to bicyclic boronates with a pendent biomolecular probe.