188296-67-5Relevant academic research and scientific papers
N-Heterocyclic Carbene/Cobalt Cooperative Catalysis for the Chemo- and Regioselective C?N Bond Formation between Aldehyde and Amines/Amides
Siddiqui, Asher M.,Khalid, Anam,Khan, Arif,Azad, Chandra S.,Samim, Mohd.,Khan, Imran A.
, p. 4281 - 4287 (2020/07/24)
A novel methodology for the construction of various secondary (4 examples), tertiary amides (31 examples), and imides (16 examples) by a Cobalt(II) catalyzed oxidative amide coupling in aqueous media. The Co(III)-TMC was reacted with N-Heteroatom Carbene to form active catalyst Co(II)NHC-TMC in situ which involves in the coordination with Breslow's intermediate and SET for the activation of aldehyde and amides. The mechanism for activation of amide and amine differs on the basis of SET based nucleophilic addition and ligand exchange respectively. The regeneration of the catalyst was achieved using Fe(III)(EDTA)-H2O2 as oxidant. The use of Co(II)TMC-O2 was also found equally efficient in the process. The method is found regioselective for N?H activation in the presence of equally susceptible ortho-C?H bond activation. And amines were found more susceptible then the corresponding amide for the reaction.
Intramolecular Vilsmeier processes: a new route to cyclopenta- and cyclohexa-fused quinolines by cyclisation of adipic and pimelic bis-amides
Meth-Cohn, Otto,Goon, Simon
, p. 85 - 90 (2007/10/03)
Symmetrical and unsymmetrical bis-amides derived from adipic and pimelic acid and secondary amines react in POCl3 solution to give the title compounds by way of a Vilsmeier reagent-α-chloro enamine interaction.Adipanilide and pimelanilide only cyclise with added PCl5.However the bis-N-substituted derivatives (N-methyl or N-phenyl) of adipanilide and pimelanilide give quinolinium salts in good yield.Unsymmetrical amides with an N-substituted anilide at one end and an aliphatic unit at the other only proceed as far as the intermediate stage, giving 1,2-disubstituted cyclo-pentanes or -hexanes.Analogous amides derived from suberic and sebacic acid do not give quinolinium salts but instead give complex mixtures.
