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Rhodium‐Induced Reversible C−C Bond Cleavage: Transformations of Rhodium(III) 22‐Alkyl‐ m ‐benziporphyrins
Author(s) -
Hurej Karolina,
Pawlicki Miłosz,
LatosGrażyński Lechosław
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201704411
Subject(s) - rhodium , chemistry , medicinal chemistry , methylene , intramolecular force , substituent , bond cleavage , reactivity (psychology) , stereochemistry , photochemistry , catalysis , organic chemistry , medicine , alternative medicine , pathology
The structurally prearranged carbaporphyrins 22‐methyl‐ and 22‐ethyl‐ m ‐benziporphyrins provide the platform stabilizing aromatic rhodium(III) 22‐(μ‐methylene‐ m ‐benziporphyrin) and rhodium(III) 22‐(μ‐ethylidene‐ m ‐benziporphyrin). An intramolecular conversion facilitated by the m ‐phenylene reactivity and observed for both aromatic complexes efficiently leads to rhodium(III) 21‐(μ‐methylene)‐21‐carbaporphyrin and rhodium(III) 21‐(μ‐ethylidene)‐21‐carbaporphyrin. The distinctive macrocyclic environment of rhodium(III) 21‐carbaporphyrin created an opportunity to trap unique organometallic transformations of inner core substituents affording the fulvene‐like bond pattern or the rearrangement to 21‐vinyl substituent. The one‐electron reduction of the rhodium(III) carbaporphyrin anion π‐radical with a (d xy ) 2 (d xz ) 2 (d yz ) 2 –(P .− ) electronic configuration is demonstrated. The further process of reduction of paramagnetic species triggers the ethyl migration from carbon(22) to rhodium(III), affording the diamagnetic rhodium(III) meta ‐benziporphyrin containing the apically coordinated σ‐ethyl ligand providing an example of reversible C(sp 2 )−C(sp 3 ) bond cleavage.