Synthesis of Functionalized Cyclopentene Derivatives from Vinyldiazo Compounds and Vinylazides through Sequential Copper‐Promoted [3+2] Cycloaddition/Azide Rearrangement

The reaction of vinylazides with alkenyldiazo compounds in the presence of [Cu(CH₃CN)₄][BF₄] provided cyclopentene derivatives with retention of the azide functionality. This process likely involves a sequence comprising: 1) decomposition of the diazo component with generation of a copper alkenylcarbene species; 2) stepwise regioselective [3+2] cycloaddition; 3) allylic azide rearrangement. This method is compatible with a broad range of substrates. We also show that the azide‐containing cycloadducts can be efficiently converted into the corresponding amine and triazole derivatives.