Le Wang, Jian Lv,* Long Zhang, and Sanzhong Luo*

A highly enantioselective and regioselective [4+2] annulation reaction of β,γ-unsaturated a-ketoesters with non-activated terminal and 1,1-disubstituted allenes was developed. The identification of a chiral cationic indium/phosphate complex is the key to achieve the current reaction. The reaction affords the corresponding C3-selective dihydropyrans in good yields and with high enantioselectivities (up to 99% ee).

This work has been published in Angew. Chem. Int. Ed. 2017, 56, 10867-10871.