The multicomponent assembly of pharmaceutically relevant N‐aryl‐oxazolidinones through the direct insertion of carbon dioxide into readily available anilines and dibromoalkanes is described. The ...addition of catalytic amounts of an organosuperbase such as Barton's base enables this transformation to proceed with high yields and exquisite substrate functional‐group tolerance under ambient CO2 pressure and mild temperature. This report also provides the first proof‐of‐principle for the single‐operation synthesis of elusive seven‐membered ring cyclic urethanes.
Come together: Carbon dioxide can be simultaneously fixated into anilines and primary dibromoalkanes under metal‐free ambient mild conditions to afford a broad range of N‐aryl‐oxazolidinones or six and seven‐membered cyclic urethanes in good yields.
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•New copper(I) catalysts for the aerobic oxidation of primary alcohols.•Ligand detachment activates the copper(I)-catalyst.•Quantitative yields are obtained of benzaldehyde in 1 ...h.•High (96%) yields are obtained of octanal.
We report here new copper(I)-Schiff base complexes for the selective oxidation of primary alcohols to aldehydes under ambient conditions (with 2,2,6,6-tetramethylpiperdine-N-oxyl (TEMPO), N-methylimidazole (NMI), ambient air, acetonitril and RT). Particularly, the copper(I) complex bearing N-(4-fluorophenyl)-1-(furan-2-yl)methanimine (L2) showed high activity in the series and gave near- quantitative yields in the oxidations of benzyl alcohol (99% yield in 1 h) and 1-octanol (96% yield in 24 h). Based on the X-ray structure determination, the complex has a square pyramidal coordination accomplished by two L2 ligands and bromide as a counter anion. The oxidation reactions were monitored with UV–vis and in situ ATR-IR spectroscopy to study the changes in the catalytic structure and to elucidate the catalytic properties and the mechanistic details. Accordingly, detachment of one of the L2 ligands from the complexes is related to the oxidation activity.
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