From Alkenes to Isoxazolines via Copper-Mediated Alkene Cleavage and Dipolar Cycloaddition.

An unprecedented copper-mediated anion transformation is reported, along with selective C═C double bond cleavage and dipolar cycloaddition reaction from simple alkenes and inexpensive copper nitrate. Various transformations demonstrate the generality of this method. Further mechanistic investigation indicates a novel ionic pathway for alkene cleavage and highlights the coeffect of iodide and boric acid as additives on the inhibition of well-documented competitive nitration byproducts.