Synthesis of a Class of Chiral-Bridged Phosphoramidite Ligands and Their Applications in the First Iridium-Catalyzed Asymmetric Addition of Arylboronic Acids to Isatins

A series
of novel chiral phosphoramidite ligands based on chiral-bridged
biphenyl backbones have been prepared conveniently and characterized.
The ligands complexed with [IrCodCl]2 provided the first
iridium catalyst system for the asymmetric addition of arylboronic
acids to N-protected isatins with high efficiency. When performed
in THF/H2O at 80 °C with 2 equiv of the arylboronic
acids, the transformations acquired good to excellent results (up
to 98% yield and 95% ee).