Premium
[Co(MeTAA)] Metalloradical Catalytic Route to Ketenes via Carbonylation of Carbene Radicals
Author(s) -
Chirila Andrei,
Vliet Kaj M.,
Paul Nanda D.,
Bruin Bas
Publication year - 2018
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201800101
Subject(s) - chemistry , carbene , ketene , nucleophile , carbonylation , catalysis , radical , organic chemistry , photochemistry , carbon monoxide , combinatorial chemistry , medicinal chemistry
An efficient synthetic strategy towards beta‐lactams, amides, and esters involving “in situ” generation of ketenes and subsequent trapping with nucleophiles is presented. Carbonylation of carbene radical intermediates using the cheap and highly active cobalt(II) tetramethyltetraaza[14]annulene catalyst [Co(MeTAA)] provides a convenient one‐pot synthetic protocol towards substituted ketenes. N ‐tosylhydrazones are used as carbene precursors, thereby bridging the gap between aldehydes and ketenes. Activation of these carbene precursors by the metalloradical cobalt(II) catalyst affords Co III ‐carbene radicals, which subsequently react with carbon monoxide to form ketenes. In the presence of a nucleophile (imine, alcohol, or amine) in the reaction medium the ketene is immediately trapped, resulting in the desired products in a one‐pot synthetic protocol. The β‐lactams formed upon reaction with imines are produced in a highly trans ‐selective manner.