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Control over the Redox Cooperative Mechanism of Radical Carbene Transfer Reactions for the Efficient Active‐Metal‐Template Synthesis of [2]Rotaxanes
Author(s) -
Alcântara Arthur F. P.,
Fontana Liniquer A.,
Almeida Marlon P.,
Rigolin Vitor H.,
Ribeiro Marcos A.,
Barros Wdeson P.,
Megiatto Jackson D.
Publication year - 2020
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.201905602
Subject(s) - porphyrin , chemistry , carbene , rotaxane , redox , moiety , photochemistry , ligand (biochemistry) , metal ions in aqueous solution , electron transfer , combinatorial chemistry , polymer chemistry , metal , stereochemistry , supramolecular chemistry , catalysis , organic chemistry , molecule , biochemistry , receptor
A 5,15‐bis(1,1′‐biphenyl)porphyrin‐based molecular clip covalently connected to a ditopic aliphatic ester loop moiety yields a semi‐rigid macrocycle with a well‐defined cavity. The resulting macrocycle fits the structural requirements for the preparation of porphyrinates capable of promoting formation of C−C bonds. To demonstrate the usefulness of porphyrin‐based macrocycles, an active‐metal‐template synthesis of rotaxanes through a redox non‐innocent carbene transfer reaction is described. Coordination of Co II ions into the porphyrin subunit followed by addition of appropriate monodentate nitrogen‐based additives to function as axial ligands enables the radical carbene transfer reactions to styrene derivatives to occur exclusively through the cavity of the macrocycle to afford cyclopropane‐linked rotaxanes in excellent 95 % yield. Investigation of the product distribution afforded from the rotaxane assembly reaction reveals how the redox cooperative action between the carbene species and the Co II ions can be manipulated to gain control over the radical‐type mechanism to favor the productive rotaxane forming process.