Palladium(0)-catalyzed rearrangement of allyl enol ethers to form chiral quaternary carbon centers via asymmetric allylic alkylation

Herein we report the first palladium(0)-catalyzed asymmetric allylic alkylation (AAA) of allyl enol ether via π-allylpalladium intermediate using Trost chiral diphosphine. This unprecedented reaction produced very rare α-aryl quaternary aldehydes with multi-functional groups. The main novelty in the chemistry demonstrates that enol ethers can be used as precursors for π-allylpalladium intermediates, an observation that is certainly rare and to the best of our knowledge, perhaps without prior precedent. Chiral ligand (R,R)-L3 was found to be optimal in this Pd-AAA reaction and provided good to excellent yield (80–95%) and enantioselectivity (70–90%) with a range of analogs.