Tingting Miao, Zi-You Tian, Yan-Mei He, Fei Chen, Ya Chen, Zhi-Xiang Yu,* and Qing-Hua Fan*

The first asymmetric hydrogenation of in situ generated isochromenylium derivatives is enabled by tandem catalysis with a binary system consisting of Cu(OTf)₂ and a chiral cationic ruthenium–diamine complex. A range of chiral 1H-isochromenes were obtained in high yields with good to excellent enantioselectivity. These chiral 1H-isochromenes could be easily transformed into isochromanes, which represent an important structural motif in natural products and biologically active compounds. The chiral induction was rationalized by density functional theory calculations.

This work has been published in Angew. Chem. Int. Ed. 2017, 56, 4135-4138.