β‐Octabromo‐ and β‐Octakis(trifluoromethyl)isocorroles: New Sterically Constrained Macrocyclic Ligands

摘要

Presented herein is a study of the acid‐induced demetalation of two sterically hindered copper corroles, Cu β‐octabromo‐meso‐triphenylcorrole (Cu[Br8TPC]) and β‐octakis(trifluoromethyl)‐meso‐tris(p‐methoxyphenyl)corrole (Cu[(CF3)8TpOMePC]). Unlike reductive demetalation, which affords the free‐base β‐octabromocorrole, demetalation of Cu[Br8TPC] under non‐ reductive conditions (CHCl3/H2SO4) resulted in moderate yields of free‐base 5‐ and 10‐hydroxy isocorroles. The isomeric free bases could be complexed to Co^II and Ni^II, affording stable complexes. Only reductive demetalation was found to work for Cu[(CF3)8TpOMePC], affording a highly saddled, hydrated corrole, H3[5‐OH,10‐H‐(CF3)8TpOMePC], where the elements of water had added across C5 and C10. Interaction of this novel free base with Co^II resulted in Co[iso‐10‐H‐[CF3)8TpOMePC], a Co^II 10‐hydro isocorrole. The new metal complexes were all characterized by single‐crystal X‐ray diffraction analysis and, despite their sterically hindered nature, were found to exhibit almost perfectly planar isocorrole cores.