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Selective C(sp 2 )‐H Amination Catalyzed by High‐Valent Cobalt(III)/(IV)‐bpy Complex Immobilized on Silica Nanoparticles
Author(s) -
Budnikova Yulia,
Bochkova Olga,
Khrizanforov Mikhail,
Nizameev Irek,
Kholin Kirill,
Gryaznova Tatyana,
Laskin Artem,
Dudkina Yulia,
Strekalova Sofia,
Fedorenko Svetlana,
Koov Aleksandr,
Mustafina Asia
Publication year - 2019
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201901391
Subject(s) - cobalt , catalysis , electrochemistry , amination , chemistry , nanoparticle , ligand (biochemistry) , coupling reaction , inorganic chemistry , reactivity (psychology) , combinatorial chemistry , materials science , organic chemistry , electrode , nanotechnology , medicine , biochemistry , receptor , alternative medicine , pathology
High‐valent cobalt IV ‐bpy complex stabilized in silica matrix was detected as catalytically active form and intermediate in cobalt‐mediated oxidative C−H/NH cross‐coupling reaction. These Co IV species prepared by electrooxidation of Co III (bpy) 3 ‐doped silica nanoparticles (SNs) at relatively low anodic potentials have demonstrated high catalytic activity. Both size and architecture of the SNs are highlighted as the factors beyond the complex structure affecting its oxidation potential and catalytic efficiency. The factors have been optimized for the catalyst with high efficiency, easy separation and reusability for 7 times at least. The optimal nanocatalyst (1 mol%) provides 100 % conversion of reactants in a single step of ligand‐directed coupling of H 2 NTs with arenes under electrochemical regeneration conditions. The results emphasize both synthetic route for efficient embedding of Co III (bpy) 3 into silica support and the electrochemical generation of Co IV complexes as a facile route for developing the efficient nanocatalyst of oxidative functionalization. The observed reactivity has the potential in development of Co‐catalyzed coupling reactions.