Catalytic Cascade Reaction To Access Cyclopentane-Fused Heterocycles: Expansion of Pd-TMM Cycloaddition.
Donguk KoSeung-Yeol BaekJae Yul ShimJu Young LeeMu-Hyun BaikEun Jeong YooPublished in: Organic letters (2019)
A palladium-catalyzed reaction of N-aromatic zwitterion and trimethylenemethane that gives fused N-heterocycles via dearomative [3 + 2] cycloaddition and intramolecular cyclization is developed, and a cyclopentane-fused cyclic product is generated. Combining computational and experimental studies, the site-selective dearomatization and the mechanism of this novel reaction are investigated in detail, and the value of pyridinium zwitterion as a reactant is demonstrated.