Probing Bowl-to-Bowl Inversion in Enantiopure Subphthalocyanines: Cofacial S _N 2 vs S _N 1 Pathways at a Tetracoordinate Boron Center

1-like component involving macrocycle planarization and inversion. Supported by analysis of different enantiopure derivatives, comparative studies with achiral analogues, kinetic measurements, and DFT calculations, we reveal that the balance between retention and inversion─and the overall reaction kinetics─is governed by the electronic and steric environment of the macrocycle, the nature of the leaving group, and the strength of the Lewis acid. Altogether, these findings deepen our understanding of boron-centered substitution mechanisms, while shedding new light on the still underexplored configurational stability of curved π-systems.