Nitrenoid from Oxime: A Practical Synthesis of Planar Chiral Ferrocenyl Phenanthridines via Nitrene‐Involved Ring‐Expansion Reaction

Abstract Nitrenes and nitrenoids are highly reactive species and the proposed key intermediates in nitrogen‐containing heterocyclic compound synthesis. In this work, we developed a practical method for the synthesis of phenanthridines by the reaction of oximes and Grignard reagents (with or without diethylzinc) via ring‐expansion of magnesium coordinated nitrenoid complex as the key step. The method has been used to synthesize optically active planar chiral ferrocenyl phenanthridines.