Synthesis of Aziridines from Alkenes and Aryl Azides with a Reusable Macrocyclic Tetracarbene Iron Catalyst

摘要

A new iron aziridination catalyst supported by a macrocyclic tetracarbene ligand has been synthesized. The catalyst, [(~(Me,Et)TC~(Ph))Fe(NCCH_3)_2](PF_6)_2, was synthesized from the tetraimidazolium precursor ( ~(Me,Et) TC~(Ph))(I)4 and characterized by NMR spectroscopy, elec-trospray ionization mass spectrometry, and single-crystal X-ray diffraction. This iron complex catalyzes the aziridination of electron-donating aryl azides and a wide variety of substituted aliphatic alkenes, including tetrasubstituted ones, in a "C_2 + N_1" addition reaction. Finally, the catalyst can be recovered and reused up to three additional times without significant reduction in yield.