Design of 1-Phosphanorbornene Derivatives as Chiral Organocatalysts for Enantioselective (4 + 2) Annulation Reactions of γ-Benzyl Allenoates
Siming Jia, Mengmeng Ma, Er‐Qing Li, Zheng Duan, Françis Mathey
Abstract
Two novel diastereoisomeric P-chirogenic phosphine catalysts, i.e., JiaPhos, which can be easily derived from inexpensive and commercially available starting materials in five chemical operations (totally 4.16g scale), are introduced. To our delight, the JiaPhos catalysts display good performance in enantioselective (4 + 2) annulations involving 3-methylene-2-oxindoles and γ-benzyl allenoates, providing a wide range of 3,3'-spirocyclic oxindoles with good efficiency and enantioselectivity.
Topics & Concepts
Enantioselective synthesisAnnulationChemistryPhosphineCatalysisCombinatorial chemistryOrganic chemistryMethyleneAsymmetric Synthesis and CatalysisAsymmetric Hydrogenation and CatalysisSynthetic Organic Chemistry Methods