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Efficient Aerobic Ruthenium‐Catalyzed Oxidation of Secondary Alcohols by the Use of a Hybrid Electron Transfer Catalyst
Author(s) -
Johnston Eric V.,
Karlsson Erik A.,
Tran LienHoa,
Åkermark Björn,
Bäckvall JanE.
Publication year - 2010
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201000033
Subject(s) - chemistry , catalysis , kinetic isotope effect , intramolecular force , ketone , yield (engineering) , alcohol oxidation , selectivity , photochemistry , steric effects , hydride , ruthenium , substrate (aquarium) , electron transfer , deuterium , racemization , organic chemistry , hydrogen , physics , materials science , oceanography , quantum mechanics , metallurgy , geology
Biomimetic aerobic oxidation of secondary alcohols has been performed using hybrid catalyst 1 and Shvo's catalyst 2. This combination allows mild reaction conditions and low catalytic loading, due to the efficiency of intramolecular electron transfer. By this method a wide range of different alcohols have been converted into their corresponding ketones. Oxidation of benzylic as well as aliphatic, electron‐rich, electron‐deficient and sterically hindered alcohols could be oxidized in excellent yield and selectivity. Oxidation of ( S )‐1‐phenylethanol showed that no racemization occurred during the course of the reaction, indicating that the hydride 2b adds to the quinone much faster than it re‐adds to the ketone product. The kinetic deuterium isotope effect of the oxidation was determined by the use of 1‐phenylethanol ( 3a ) and 1‐deuterio‐1‐phenylethanol ( 3a‐d1 ) in parallel and competitive manner, which gave the same isotope effect within experimental error ( k H / k D ≈ 2.8). This indicates that there is no strong coordination of the substrate to the catalyst.