A new palladium-catalyzed selective aminomethylation of conjugated 1,3-dienes with aminais via double C-N bond activation is described. This simple method provides an effective and rapid approach for the synthesis of ...A new palladium-catalyzed selective aminomethylation of conjugated 1,3-dienes with aminais via double C-N bond activation is described. This simple method provides an effective and rapid approach for the synthesis of linear a,13-unsaturated allylic amines with perfect regioselectivity. Mechanistic studies disclosed that one palladium catalyst cleaved two distinct C-N bond to furnish a cascade double C-N bond activation, in which an allylic 1,3-diamine and allylic 1,2-diamine were initially formed as key intermediates through the palladium-catalyzed C-N bond activation of aminal and the α,β-unsaturated allylic amine was subsequently produced via palladium-catalyzed C-N bond activation of the allylic diamines.展开更多
Computational investigations of Cu（I）-catalyzed C--N coupling between aryl halides and aqueous ammonia without addition of any base or ligand were reported. Density functional theory calculations were performed to r...Computational investigations of Cu（I）-catalyzed C--N coupling between aryl halides and aqueous ammonia without addition of any base or ligand were reported. Density functional theory calculations were performed to re- veal the mechanism of the ligand-free amination reaction for the preparation of primary aromatic amines. Through systematic evaluation of the relative concentrations of possible Cu species in solution, we propose that the active catalyst is the neutral Cu（I） complexes rather than the Cu（I） cations; oxidative addition of aryl bromide is a facile step of the catalytic cycle; reactant （NH3） and solvent molecule （NMP） can act as ligands of Cu species to help re- duce the activation energy of the forward reaction and increase the activation energy of the reverse reaction; except for Pathway B, the deprotonation step is irreversible due to the extreme exothermic feature; the elimination of H20 is kinetically favored, while that of HBr is thermodynamically preferred. These findings should be valuable for the mechanism understandings of the ligand-free Cu-catalyzed C--N cross-coupling reactions and for the further de- velopment of highly efficient amination catalyst systems.展开更多
基金This research was supported by the National Natural Science Foundation of China （Nos. 21672199 and 21790333） and CAS Interdisciplinary Innovation Team.
文摘A new palladium-catalyzed selective aminomethylation of conjugated 1,3-dienes with aminais via double C-N bond activation is described. This simple method provides an effective and rapid approach for the synthesis of linear a,13-unsaturated allylic amines with perfect regioselectivity. Mechanistic studies disclosed that one palladium catalyst cleaved two distinct C-N bond to furnish a cascade double C-N bond activation, in which an allylic 1,3-diamine and allylic 1,2-diamine were initially formed as key intermediates through the palladium-catalyzed C-N bond activation of aminal and the α,β-unsaturated allylic amine was subsequently produced via palladium-catalyzed C-N bond activation of the allylic diamines.
文摘Computational investigations of Cu（I）-catalyzed C--N coupling between aryl halides and aqueous ammonia without addition of any base or ligand were reported. Density functional theory calculations were performed to re- veal the mechanism of the ligand-free amination reaction for the preparation of primary aromatic amines. Through systematic evaluation of the relative concentrations of possible Cu species in solution, we propose that the active catalyst is the neutral Cu（I） complexes rather than the Cu（I） cations; oxidative addition of aryl bromide is a facile step of the catalytic cycle; reactant （NH3） and solvent molecule （NMP） can act as ligands of Cu species to help re- duce the activation energy of the forward reaction and increase the activation energy of the reverse reaction; except for Pathway B, the deprotonation step is irreversible due to the extreme exothermic feature; the elimination of H20 is kinetically favored, while that of HBr is thermodynamically preferred. These findings should be valuable for the mechanism understandings of the ligand-free Cu-catalyzed C--N cross-coupling reactions and for the further de- velopment of highly efficient amination catalyst systems.
