Highly enantioselective Pd(II)-catalyzed Wacker-type cyclization of 2-allylphenols by use of bisoxazoline ligands with axis-unfixed biphenyl backbone

A series of axis-unfixed bisoxazoline ligands with different steric and electronic properties was synthesized and applied in Pd(II)-catalyzed intramolecular Wacker-type cyclization of allylphenols with high catalytic activity and excellent enantioselectivity (up to 98% ee).