Chiral Cyclic Ligand-Enabled Iridium-Catalyzed Asymmetric Arylation of Unactivated Racemic Allylic Alcohols with Anilines

A highly enantioselective
arylation of unactivated racemic secondary
allylic alcohols with aniline derivatives has been developed. The
transformation was enabled by an iridium–chiral cyclic phosphoramidite
complex in the presence of boron trifluoride diethyl etherate as the
promoter, and the reactivity and enantioselectivity of the substrates
were tuned by the variation of our newly developed chiral cyclic phosphoramidite
ligands together with temperature and solvents. The method shows advantages
including use of the readily available starting materials, an operationally
convenient protocol, full regioselectivity and excellent enantioselectivity,
and tolerance of many functional groups with water as the only byproduct.