Palladium‐Catalyzed Transient Chirality Transfer and Atroposelective C‐H Functionalization to Access Quaternary Stereocenters

Abstract

AbstractAlthough palladium‐catalyzed asymmetric C−H functionalization and Heck reactions represents one of the most important synthetic strategies for the construction of quaternary stereocenters, developing the enantioselective version of PdII‐catalyzed carbopalladation‐initiated cascade reactions still remains a formidable challenge. Herein, an unprecedent enantioselective [3+2] annulation of oxime ethers and alkynes has been developed, providing both spiro and nonspiro indenes bearing all‐carbon quaternary stereocenters in good yields (up to 98 %) with excellent enantioselectivities (up to >99 % ee). This annulation is accomplished by merging the PdII‐catalyzed atroposelective C−H activation/double carbopalladation and the transient axial‐to‐central chirality transfer process, constituting the first successful example of catalytic chirality transfer strategy involving axially chiral styrene intermediate.