title: Rhodium(II)-Catalyzed Cycloaddition Reactions of Non-classical 1,5-Dipoles for the Formation of Eight-Membered Heterocycles.
abstract: A new type of intermolecular rhodium(II)-catalyzed [5+3] cycloaddition has been developed. This higher-order cycloaddition between pyridinium zwitterion 1,5-dipole equivalents and enol diazoacetates enables the formation of eight-membered heterocyclic skeletons, which are otherwise difficult to construct. The optimized cycloaddition occurs efficiently under mild conditions with a wide range of pyridinium zwitterions and with high functional-group tolerance.
authors.affiliation: Department of Chemistry, Kangwon National University, 1 Kangwondaehak-gil, Chuncheon, 200-701 (Republic of Korea).
authors.forename: Dong Jin
authors.initials: DJ
authors.lastname: Lee
authors.affiliation: Department of Chemistry, Kangwon National University, 1 Kangwondaehak-gil, Chuncheon, 200-701 (Republic of Korea).
authors.forename: Donguk
authors.initials: D
authors.lastname: Ko
authors.affiliation: Department of Chemistry, Kangwon National University, 1 Kangwondaehak-gil, Chuncheon, 200-701 (Republic of Korea). ejyoo@kangwon.ac.kr.
authors.forename: Eun Jeong
authors.initials: EJ
authors.lastname: Yoo
keywords: cycloaddition; eight-membered heterocycles; homogeneous catalysis; rhodium; zwitterions