Recognition-mediated regiocontrol of a dipolar cycloaddition reaction

The rational design of a recognition-based system that is capable of accelerating and controlling the regiochemical outcome of a dipolar cycloaddition reaction between an azide and an alkyne is presented. The origins of the acceleration and control of the cycloaddition reactions are rationalized—using molecular mechanics calculations—in terms of the formation of a complex between the reagents which organizes and orients them prior to reaction.