Open Accessβ‐Octabromo‐ and β‐Octakis(trifluoromethyl)isocorroles: New Sterically Constrained Macrocyclic Ligands
Author(s) -
Thomas Kolle E.,
Beavers Christine M.,
Gag Kevin J.,
Ghosh Abhik
Publication year - 2017
Publication title -
chemistryopen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 29
ISSN - 2191-1363
DOI - 10.1002/open.201700035
Subject(s) - steric effects , corrole , chemistry , trifluoromethyl , free base , copper , fluorine , metal , medicinal chemistry , crystallography , base (topology) , stereochemistry , photochemistry , organic chemistry , mathematical analysis , salt (chemistry) , mathematics , alkyl
Presented herein is a study of the acid‐induced demetalation of two sterically hindered copper corroles, Cu β‐octabromo‐ meso ‐triphenylcorrole (Cu[Br 8 TPC]) and β‐octakis(trifluoromethyl)‐ meso ‐tris( p ‐methoxyphenyl)corrole (Cu[(CF 3 ) 8 T p OMePC]). Unlike reductive demetalation, which affords the free‐base β‐octabromocorrole, demetalation of Cu[Br 8 TPC] under non‐ reductive conditions (CHCl 3 /H 2 SO 4 ) 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[(CF 3 ) 8 T p OMePC], affording a highly saddled, hydrated corrole, H 3 [5‐OH,10‐H‐(CF 3 ) 8 T p OMePC], where the elements of water had added across C 5 and C 10 . Interaction of this novel free base with Co II resulted in Co[ iso ‐10‐H‐[CF 3 ) 8 T p OMePC], 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.