Theoretical investigations on copper catalyzed CN cross-coupling reaction between aryl chlorides and amines

Publication date: 15 June 2018 Source:Computational and Theoretical Chemistry, Volume 1134 Author(s): Khalil Ahmad, Bilal Ahmad Khan, Bilal Akram, Jahanzeb Khan, Rashid Mahmood, Soumendra K. Roy The mechanism of CuI/oxalic diamide catalyzed arylation of amines with chlorobenzene was investigated computationally. CuI/N,N′-bis(2,4,6-trimethoxyphenyl)-oxalamide (BTMPO) system was selected as model catalytic system. On the basis of relative Gibbs free energy, five different possible intermediate Cu1 complexes were selected for mechanistic studies. Intermediate complexes Int1–Int3 have a BTMPO ligand deprotonated at one or both NH groups and a benzylamine or benzylamide group coordinated to Cu1. Intermediate Int4 has a mono deprotonated BTMPO and an ƞ 2-coordinated chlorobenzene ligand. Int5 is anionic analogue of Int4 in which both NH groups of the BTMPO ligand are deprotonated. DFT calculations were carried out for oxidative addition/reductive elimination and single electron transfer mechanisms. Int2 shows the lowest activation energy barrier (23.5 kcal/mol) for oxidative addition/reductive elimination mechanism. All the intermediates show higher activation energy for single electron transfer mechanism than oxidative addition/reductive elimination mechanism of Int2. Graphical abstract

Source: Computational and Theoretical Chemistry - May 3, 2018 Category: Chemistry Source Type: research