A Continuously Regenerable Chiral Ammonia Borane for Asymmetric Transfer Hydrogenations
作者:Qiwen Zhou、Wei Meng、Jing Yang、Haifeng Du
DOI:10.1002/anie.201806877
日期:2018.9.10
A novel chiral ammonia borane was designed and developed through the dehydrogenation of ammonia borane with a chiral phosphoric acid, which was highly effective for the asymmetric transfer hydrogenation of imines and β‐enamino esters to afford high levels of reactivities and enantioselectivities. Significantly, this chiral ammonia borane can be continuously regenerated during the transfer hydrogenation
Ortho-selective C–H borylation of aromaticketones has not been extensively explored. Herein, we report the iridium-catalyzed ortho-selective C–H borylation of aromaticketones using in situ-formed imine as the ligand. Good compatibility is observed for various substituted acetophenones and otheraromaticketones, and corresponding products are obtained with medium to excellent yields.