Cycloadditions of Donor-Acceptor Cyclopropanes and Nitriles

Lewis acid promoted cycloaddition reactions of donor-acceptor (DA) cyclopropanes are one of the well-studied approaches for the construction of heterocyclic and carbocyclic frameworks. During our efforts to exploit this strategy for the synthesis and functionalization of carbohydrate-derived systems, we discovered the cycloaddition of nitriles with DA cyclopropanes. This personal account details our contributions to the development of this cycloaddition. The reaction discovery, methods development, and application in total synthesis along with related examples from others are discussed herein.