Catalytic Enantioselective Arylation of <i>N</i>-Tosylarylimines with Arylboronic Acids Using <i>C</i>₂-Symmetric Cationic <i>N</i>-Heterocyclic Carbene Pd²⁺ Diaquo Complexes

Abstract

The asymmetric arylation of N-tosylimines with arylboronic acids was realized by using chiral cationic C(2)-symmetric N-heterocyclic carbene (NHC) Pd(2+) diaquo complex 5b as the catalyst in combination with 1.0 equiv of K(3)PO(4) x 3 H(2)O in THF at 4 degrees C in the presence of powdered 4 A MS to afford the corresponding adducts in excellent yields (up to 99%) and good to high enantioselectivities (up to 94% ee).