54436-58-7Relevant articles and documents
Hydroamination/cyclization of aminoalkenes using cationic zirconocene and titanocene catalysts
Gribkov, Denis V.,Hultzsch, Kai C.
, p. 5542 - 5546 (2004)
Alternative catalysts: The hydroamination of nonactivated double bonds has been the domain of rare-earth-metal catalysts. Now alkyl zirconocene and titanocene cations, which are readily prepared from commercially available precursors, are shown to be active catalysts in the hydroamination/cyclization of secondary aminoalkenes to give tertiary pyrrolidines and piperidines.
Modular Entry to Functionalized Tetrahydrobenzo[ b]azepines via the Palladium/Norbornene Cooperative Catalysis Enabled by a C7-Modified Norbornene
Dong, Guangbin,Liu, Xin,Wang, Jianchun
supporting information, p. 9991 - 10004 (2021/07/19)
Tetrahydrobenzo[b]azepines (THBAs) are commonly found in many bioactive compounds; however, the modular preparation of functionalized THBAs remains challenging to date. Here, we report a straightforward method to synthesize THBAs directly from simple aryl iodides via palladium/norbornene (Pd/NBE) cooperative catalysis. Capitalizing on an olefin-tethered electrophilic amine reagent, an ortho amination followed by 7-exo-trig Heck cyclization furnishes the seven-membered heterocycle. To overcome the difficulty with ortho-unsubstituted aryl iodide substrates, we discovered a unique C7-bromo-substituted NBE (N1) to offer the desired reactivity and selectivity. In addition to THBAs, synthesis of other benzo-seven-membered ring compounds can also be promoted by N1. Combined experimental and computational studies show that the C7-bromo group in N1 plays an important and versatile role in this catalysis, including promoting β-carbon elimination, suppressing benzocyclobutene formation, and stabilizing reaction intermediates. The mechanistic insights gained could guide future catalyst design. The synthetic utility has been demonstrated in a streamlined synthesis of tolvaptan and forming diverse pharmaceutically relevant THBA derivatives. Finally, a complementary and general catalytic condition to access C6-substituted THBAs from ortho-substituted aryl iodides has also been developed.
Use of (cyclopentadienone)iron tricarbonyl complexes for c-n bond formation reactions between amines and alcohols
Brown, Thomas J.,Cumbes, Madeleine,Diorazio, Louis J.,Clarkson, Guy J.,Wills, Martin
, p. 10489 - 10503 (2018/05/31)
The application of a series of (cyclopentadienone)iron tricarbonyl complexes to "borrowing hydrogen" reactions between amines and alcohols was completed in order to assess their catalytic activity. The electronic variation of the aromatic groups flanking the C?O of the cyclopentadienone influenced the efficiency of the reactions; however, in other cases, the Kn?lker catalyst 1, containing trimethylsilyl groups flanking the cyclopentadienone ketone, gave the best results. In some cases, the change of the ratio of amine to alcohol improves the conversion significantly. The application of iron catalysts to the synthesis of a range of amines, including unsaturated amines, was investigated.
