Palladium-Catalyzed Monoarylation of Arylhydrazines with Aryl Tosylates

A palladium-catalyzed
C–N bond coupling reaction between
arylhydrazines and aryl tosylates for facile synthesis of unsymmetrical N,N-diarylhydrazines has been developed.
Employing the catalyst system of Pd­(TFA)2 associated with
newly developed phosphine ligand L1, the monoarylation
of arylhydrazine proceeds smoothly to afford desired products in good-to-excellent
yields (up to 95%) with good functional group compatibility. This
method provides an alternative synthetic pathway for accessing structurally
diversified N,N-diarylhydrazines
from simple and easily accessible coupling components.