6118-19-0Relevant academic research and scientific papers
Investigations into the mechanism of the liquid-phase hydrogenation of nitriles over Raney-Co catalysts
Schaerringer, Peter,Mueller, Thomas E.,Lercher, Johannes A.
, p. 167 - 179 (2008/09/17)
The co-hydrogenation of acetonitrile and butyronitrile over Raney-Co was investigated in order to obtain insight into the mechanism underlying the formation of secondary amines. Acetonitrile was reduced much faster to the corresponding primary amine due to stronger adsorption on the catalyst surface. In parallel, dialkylimines were formed and subsequently converted to secondary amines. It is suggested that the dialkylimines are formed by reaction of partially hydrogenated intermediate species on the cobalt surface with amines. In this respect, n-butylamine was found to react much faster than ethylamine. The stronger inductive effect of the butyl chain is thought to facilitate nucleophilic attack of the amine at the α-C-atom of the surface species. By comparing the C2 and C4 balance for dialkylimines and dialkylamines, it was found that direct hydrogenation of the dialkylimine cannot be the only way of dialkylamine formation. Instead, it is suggested that alkyl group transfer occurs by reaction of a monoalkylamine with a dialkylimine and cross-transfer between two dialkylimines.
Gas-Phase Chemistry of Protonated Ethylamine: A Mass Spectrometric and Molecular Orbital Study
Bouchoux, Guy,Djazi, Feycal,Nguyen, Minh Tho,Tortajada, Jeanine
, p. 3552 - 3556 (2007/10/03)
The unimolecular dissociation of protonated ethylamine, (+), 1, has been examined by both mass spectrometric techniques and molecular orbital calculations.Metastable dissociations of various deuterated species demonstrate that the loss of ethene from 1 involves specifically a transfer of a hydrogen atom from the methyl to the NH2 group.A very limited scrambling (4percent) of the hydrogen atoms of the ethyl moiety is observed.Ab initio molecular orbital calculations have been performed at the MP4SDTQ/6-311G**//MP2/6-31G*+ZPE level of theory to examine the mechanism of the unimolecular dissociation of ions 1.It appears that 1 loses a molecule of ethene after a rate-determining isomerization into a proton-bound complex: (+), 2.The marginal hydrogen scrambling is accounted for by 1,2-H shifts on the ethyl group inside a second, loosely bonded, complex involving an ethyl cation and a molecule of ammonia: (+),3.
The Collision-Induced Dissociations of Deprotonated Amines in the Gas Phase
Raftery, Mark J.,Bowie, John H.
, p. 1477 - 1489 (2007/10/02)
The major collision-induced fragmentations of deprotonated primary and secondary amines are best rationalized as proceeding through the intermediacy of ion complexes.For example, the characteristic fragmentation of deprotonated ethylamine is MeCH2NH- -> -(CH2=NH)> -> CH2N- + CH4 Secondary alkylamines behave in a similar fashion.The occurrence of proton transfer as a prelude to fragmentation is rare: the only example observed in this study is the probable reaction PhNEt ->-> PhNHCHMe -> -> -> C7H6N- + CH4 which is preceded or accompanied by proton transfer between the methylene and phenyl substituents.Deprotonated aniline undergoes specific elimination of CNH from the 1-position to form the cyclopentadienyl anion.Finally, retro reactions are observed for the piperazine anion, e.g.HN(CH2CH2)2N- -> -CH2CH2N=CH2 + CH2NH
