Chiral Bidentate Boryl Ligand Enabled Iridium-Catalyzed Enantioselective C(sp~3)-H Borylation of Cyclopropanes

摘要

We herein report an Ir-catalyzed enantioselective C(sp(3))-H borylation of cyclopropanecarboxamides using a chiral bidentate boryl ligand for the first time. A variety of substrates with alpha-quaternary carbon centers could be compatible in this reaction to provide beta-borylated products with good to excellent enantioselectivities. We have also demonstrated that the borylated products can be used as versatile precursors engaging in stereospecific transformations of C-B bonds, including the synthesis of a bioactive compound Levomilnacipran.