An efficient way to access highly functionalized proline derivatives was developed based on a Cu(I)-catalyzed reaction between CF3-substituted allenynes and tosylazide, which involved a cascade of [3 + 2]-cycloaddition/ketenimine and a rearrangement/Alder-ene cyclization to afford the new proline framework with a high diastereoselectivity.
Keywords: 1,2,3-triazoles; 1,6-allenynes; alder-ene reaction; catalysis; cycloaddition; prolines.