Conceptual Expansion of Virtual Ligand Strategy Toward the Design of Triarylborane Catalysts

Triarylboranes are among the most important classes of Lewis acid catalysts. However, the molecular design of triarylborane still relies on conventional trial-and-error strategies. This study introduces the virtual borane (VB) method, an original computational approach for the design of triarylborane based on the previously reported virtual ligand strategy. Using quantum chemical calculations, the VB reproduces the electronic and steric properties of various triarylboranes without explicitly requiring knowledge of their molecular structures. This, in turn, enables the rapid parameter-based optimization of the catalyst properties, affording rational and quantitative guidelines for molecular design. The accuracy of the VB method was validated by reproducing the energy diagrams of borane-catalyzed reactions. The utility of this method was demonstrated by virtual borane-assisted optimization, in which the optimal properties for transfer hydrosilylation were rapidly determined by numerical optimization of the VB parameters. The VBAO calculations were used to predict a superior catalyst, which was computationally validated.