The Latest Insights into Multiply Selective Diels–Alder Reactions Using a Chiral‐Cavity‐Structured Lewis‐Acidic Boron Catalyst

The latest insights into multiply selective Diels–Alder (DA) reactions is presented, where a chiral‐cavity‐structured Lewis‐acidic boron catalyst is employed. The catalyst ((R)‐1) is capable of recognizing both dienes and dienophiles, primarily due to the influence of the suitable steric factors of its cavity. By taking advantage of the structural and exo‐product‐inducing properties of (R)‐1, even in the presence of a mixture of inseparable dienes, the target products were successfully obtained in high yield with high enantioselectivity. As (R)‐1 exhibited the capacity to differentiate between three‐dimensional isomeric transition‐state structures in DA reactions, this work contributes to the advancement of artificial enzyme‐like catalysis, which has so far remained elusive.