Asymmetric Allylic Alkylation with Deconjugated Carbonyl Compounds: Direct Vinylogous Umpolung Strategy

作者：Guang‐Yao Ran, Xing‐Xing Yang, Jing‐Fei Yue, Wei Du, Ying‐Chun Chen · 发表于：Angewandte Chemie International Edition · 年份：2019 · DOI：10.1002/anie.201903478 · 被引用次数：61 · 研究领域：Asymmetric Synthesis and Catalysis、Catalytic C–H Functionalization Methods、Asymmetric Hydrogenation and Catalysis

Abstract An atom‐economic and highly efficient vinylogous umpolung strategy is developed for deconjugated carbonyl compounds, which generate electron‐deficient π‐allylpalladium complexes with Pd(OAc) 2 under ligand‐free conditions. In cooperation with a chiral‐phosphonium‐based phase‐transfer catalyst, the asymmetric direct oxidative allylic alkylations of 3‐substituted oxindoles are furnished under O 2 atmosphere. The γ‐ or even remote ϵ‐regioselective alkylation products, with substantial substituents, are delivered with excellent enantioselectivity, and can be further used to access diverse chiral spirocyclic architectures effectively. The Mukaiyama dienol silyl ether can be utilized similarly, indicating that the current active π‐allylpalladium species results from tautomerization of the Pd II ‐dienolate intermediate.