Acid-Catalyzed [3,3] Sigmatropic Rearrangement of N-Cbz-Diaryl Hydrazide for the Synthesis of Mono-N-Cbz-1,1′-biaryl-2,2′-diamine

N‐Cbz‐Diaryl hydrazides undergo acid‐catalyzed [3,3] sigmatropic rearrangement to afford N‐Cbz‐1,1′‐biaryl‐2,2′‐diamines. The resultant products can be versatile synthetic platforms for a wide variety of C2‐ and/or nonsymmetric axially chiral ligands and organocatalysts. N‐Cbz‐Diaryl hydrazides bearing either a neutral or electron‐donating group underwent highly efficient acid‐catalyzed [3,3] sigmatropic rearrangement to afford N‐Cbz‐1,1′‐biaryl‐2,2′‐diamines. The resultant products allow elaboration of various new C2‐ and/or nonsymmetric axially chiral ligands or organocatalysts.