Substrate-Controlled Enantiodivergence in Ni-Catalyzed Access to Phosphorylated Oxindoles With Quaternary
Haimeng Zhu1, Lewen Wang1,2, Shihui Luo1
1Department of Chemistry, Hong Kong Baptist University, Hong Kong, China.
Abstract:
A Ni-catalyzed enantioselective intermolecular Heck-phosphorylation of N-aryl acrylamides with phosphine oxides is developed. This redox-neutral cascade simultaneously forges C─C and C─P bonds, providing direct access to valuable 3,3-disubstituted phosphorylated oxindoles with quaternary stereocenters in good yields and high ee values. Notably, the reaction exhibits a unique substrate-controlled enantiodivergence: simply changing the leaving group (I vs. OTf) on the alkene partner switches the configuration of the product while employing the same enantiomer of the chiral catalyst. The synthetic utility is further demonstrated through product derivatizations. Density functional theory (DFT) calculations reveal that the leaving group dictates the order of migratory insertion versus anion exchange and, crucially, inverts the chiral environment at the enantioselectivity-determining oxidative addition transition state, providing a clear rationale for the observed stereodivergence.
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