Design Principles to Promote Acid–Base Interactions with a Weak Second-Sphere Lewis Acid

Boronic esters such as BPin are underutilized in secondary-sphere chemistry due to their weak acidity. We report a design strategy to enable cooperative binding with a BPin-appended NHC scaffold. Employing a shortened tether enhances preorganization and facilitates substrate binding in tandem with the metal center. Experimental and computational analyses clarify principles of the design that enable cooperativity.