Formal [3 + 2] Cycloadditions of Donor−Acceptor Cyclopropanes and Nitriles

Donor−acceptor cyclopropanes activated with Me3SiOTf cleave to reactive intermediates that can be efficiently intercepted by nitriles in a formal [3 + 2] dipolar cycloaddition reaction. Aliphatic, aromatic, and α,β-unsaturated nitriles are excellent reaction partners, giving synthetically useful 2H-3,4-dihydropyrrole cycloaddition products in high yield.