Polycyclic Scaffolds through the Intermediacy of Boron-Stabilized Nonclassical Carbocations

In the presence of catalytic amounts of Brønsted acid, boron-containing norbornene derivatives undergo a regioselective rearrangement to furnish boron-containing nortricyclanes. The unique stabilization of the putative 2-norbornyl cation by the boron substituent was investigated through both experimental and computational studies. Selective functionalization of the boronic ester product enables access to a diverse array of multisubstituted tricyclic structures, providing opportunities for broader applications.