118-44-5Relevant articles and documents
Conformational Studies by Dynamic NMR. 32. Enantiomerization of Chiral Conformers in Hindered Naphthylamines and Naphthyl Nitroxides
Casarini, D.,Lunazzi, L.,Placucci, G.,Macciantelli, D.
, p. 4721 - 4726 (1987)
Observation of anisochronous NMR signals in N-alkyl-N-methyl-1-naphthylamines at low temperature indicates that these molecules adopt a twisted conformation (yielding enantiomeric conformers at the equilibrium) as opposed to the corresponding N-alkyl-N-methyl-2-naphthylamines which give two planar (thus achiral) conformers.The barriers to enantiomerization in 1-naphthylamines have been measured by line-shape analysis for those amines containing prochiral substituents.The use at low temperature of one of the Pirkle's chiral alcohols as a discriminating agent allowed these barriers to be measured even in absence of prochiral grpups.Related alkyl 1-naphthyl nitroxides were also shown to prefer a twisted conformation, but the enantiomerization barriers are too low to be measured by ESR.Examination of a much more hindered nitroxide (2-tert-butyl-1-naphthyl ethyl nitroxide) showed that the methylenic hydrogens were anisochronous even at room temperature, indicating that this radical exist as a racemic mixture.The existence of an exponential relationship between the free energies of enantiomerization in the 1-naphthylamines and the nitrogen hyperfine splittings in the analogous nitroxides allowed the barrier for N,N-dimethyl-1-naphthylamine to be estimated.This barrier could not be measured directly because of the symmetry of the amine.
Homogeneous cobalt-catalyzed deoxygenative hydrogenation of amides to amines
Papa, Veronica,Cabrero-Antonino, Jose R.,Spannenberg, Anke,Junge, Kathrin,Beller, Matthias
, p. 6116 - 6128 (2020/11/03)
The first general and efficient cobalt-catalyzed deoxygenative hydrogenation of amides to amines is presented. The optimal catalytic system based on a combination of [Co(NTf2)2] and (p-anisyl)triphos (L3) in the presence of [Me3SiOTf] as acidic co-catalyst facilitates the direct hydrogenation of a broad range of amides to the corresponding amines under mild conditions. A set of control experiments indicate that, after the initial reduction of the amide carboxylic group to the well-known hemiaminal intermediate, the reaction mainly proceeds through C-O bond cleavage though other pathways might be also involved to a minor extent. This journal is
Cobalt-Catalyzed Reductive Alkylation of Amines with Carboxylic Acids
Emayavaramban, Balakumar,Chakraborty, Priyanka,Sundararaju, Basker
, p. 3089 - 3093 (2018/12/11)
Direct reductive alkylation of amines with carboxylic acid is carried out by using an inexpensive, air-stable cobalt/triphos catalytic system with molecular hydrogen as the reductant. This efficient synthetic method proceeds through reduction and condensation, followed by reduction of the in situ-generated imine into the amine in a green catalytic process.
