Triptycepenes: Synthesis, Metal Complexes, and Their Reactivity in Catalytic Reactions

An efficient protocol allows the convenient synthesis of substituted triptycepenes through the condensation of anthracene α-diketone with 3-pentanone or 1,3-diphenylpropan-2-one, finally yielding the corresponding cyclopentadienones. This approach offers a potential route toward sterically bulky cyclopentadienyl ligand frameworks. The methyl-substituted triptycepene was used to generate η⁵-coordinated Ru and Co complexes as well as an η⁴-coordinated Fe complex. These metal complexes were characterized by single-crystal X-ray diffraction, and their exemplary catalytic activity in metal-catalyzed reactions like cyclotrimerization, C-H functionalization, and transfer hydrogenation was investigated.