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Selective Hydrogenation of α,β‐Unsaturated Aldehydes and Ketones by Air‐Stable Ruthenium NNS Complexes
Author(s) -
Puylaert Pim,
van Heck Richard,
Fan Yuting,
Spannenberg Anke,
Baumann Wolfgang,
Beller Matthias,
Medlock Jonathan,
Bonrath Werner,
Lefort Laurent,
Hinze Sandra,
de Vries Johannes G.
Publication year - 2017
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.201700806
Subject(s) - ruthenium , aldehyde , chemistry , triphenylphosphine , ligand (biochemistry) , allylic rearrangement , catalysis , base (topology) , transfer hydrogenation , organic chemistry , medicinal chemistry , combinatorial chemistry , mathematical analysis , biochemistry , receptor , mathematics
The selective hydrogenation of the carbonyl functionality of α,β‐unsaturated aldehydes and ketones is catalysed by ruthenium dichloride complexes bearing a tridentate NNS ligand as well as triphenylphosphine. The tridentate ligand backbone is flexible, as evidenced by the equilibrium observed in solution between the cis ‐ and trans ‐isomers of the dichloride precatalysts, as well as crystal structures of several of these complexes. The complexes are activated by base in the presence of hydrogen and readily hydrogenate carbonyl functionalities under mild conditions. Despite the activation by base, side reactions are negligible, even for aldehyde substrates, because of the low amount of base. Thus, the corresponding allylic alcohols can be isolated in very good yields on a 10–25 mmol scale. Turnover numbers up to 200 000 were achieved.