Chen, H.; Caughey, R.; Liu, R.; McMills, M.; Rupp, M.; Myers, W.; Harman, W. D. Novel Cyclization Reactions with η2-Furan Complexes. Tetrahedron 2000, 56, 2313-2323.
Abstract
A series of complexes has been prepared of the form [Os(NH3)5(4,5-η2-L)]2+ where L=furan and various 2-alkylated furans. Electrophilic addition to C(3) results in an unstable reaction intermediate, a 4,5-η2-3H-furanium species, that leads to several novel cyclization reactions with tethered nucleophiles to form new heterocycles.
