2011
deHope, A.; Mendoza-Espinosa, D.; Donnadieu, B.; Bertrand, G. A Persistent(Amino)(Ferrocenyl)carbene. New J. Chem. 2011, 35, 2037-2042
Abstract
Deprotonation of N,N-diisopropyl-C-ferrocenylaldiminium triflate 2 cleanly leads to the corresponding 1,2-diamino-1,2-diferrocenylethene 3, the dimer of the desired (amino)(ferrocenyl)carbene. Fulvene 6, obtained by addition of the lithium salt of tetramethylcyclopentadiene to methoxyformamidinium methylsulfate 5, reacts with dicarbonylcyclopentadienylbromoiron(II), and with a mixture of FeCl2 and Cp* lithium salt, affording the corresponding tetramethylferrocenylaldiminium salt 7, and nonamethylferrocenylaldiminium salt 8, respectively. Although the deprotonation of 7 gives a complex mixture of products, the treatment of 8 at ?78 C with sodium hexamethyldisilazide allowed for the isolation of the corresponding (amino)(ferrocenyl)carbene 9 as a yellow powder. However, even in the solid state, it is stable for less than 48 h at ?20 C. In addition to NMR spectroscopy, evidence for the carbene nature of 9 was found by a trapping experiment with sulfur that leads to the corresponding adduct 10, which was characterized by a single crystal X-ray diffraction study.
Total Syntheses of Five Indole Alkaloids from the Marine Bryozoan Flustra foliacea
Cleavage of alkoxycarbonyl protecting groups from carbamates by t-BuNH2
13C NMR and crystallographic evidence of push-pull effects in furoindolic ?-enamino esters
Aromatic Bromination versus Oxidation of Indolylmalonates by Bromine
Conformational studies on indole alkaloids from Flustra foliacea by NMR and molecular modeling
The absoluteconfiguration of cuauhtemone and related compounds
Synthesis of Acetamido(indol-3-yl)propanol Derivatives