Computational Analysis on the Pd-Catalyzed C-N Coupling of Ammonia with Aryl Bromides Using a Chelate Phosphine Ligand.

The Buchwald-Hartwig amination of arylhalides with the Pd-Josiphos complex is a very useful process for the generation of primary amines using ammonia as a reactant. Density-functional theory (DFT) calculations are carried out to examine the reaction mechanism for this process. Although the general mechanism for the C-N cross-coupling reaction is known, there are still some open questions regarding the effect of a chelate phosphine ligand and the role of the base in the process. Reaction pathways involving the release of one of the arms of the phosphine ligand are compared with those where the chelate phosphine remains fully coordinated. Conformational analysis for the complex with the open chelate phosphine is required to properly evaluate the proposed pathways. The role played by the added base (t-BuO-) as a possible ligand or just as a base was also evaluated. The understanding of all of these aspects allowed us to propose a complete reaction mechanism for the Pd-catalyzed C-N coupling of arylhalides with ammonia using the chelate Josiphos ligand.

Transmetalation Reactions Triggered by Electron Transfer between Organocopper Complexes.

[Cu(bipy)(C6F5)] reacts with most aryl iodides to form heterobiphenyls by cross-coupling, but when Rf-I is used (Rf = 3,5-dicholoro-2,4,6-trifluorophenyl), homocoupling products are also formed. Kinetic studies suggest that, for the homocoupling reaction, a mechanism based on transmetalation from [Cu(bipy)(C6F5)] to Cu(III) intermediates formed in the oxidative addition step is at work. Density functional theory calculations show that the interaction between these Cu(III) species and the starting Cu(I) complex involves a Cu(I)-Cu(III) electron transfer concerted with the formation of an iodine bridge between the metals and that a fast transmetalation takes place in a dimer in a triplet state between two Cu(II) units.

ESIgen: Electronic Supporting Information Generator for Computational Chemistry Publications.

Electronic supporting information (ESI) occupies a fundamental position in the way scientists report their work. It is a key element in lightening the writing of the core manuscript and makes concise communication easier for the authors. Computational chemistry, as all fields related to structural studies of molecules, tends to generate huge amounts of data that should be inserted in the ESI. ESI reports originating from computational chemistry works generally reach tens of sheets long and include 3D depictions, coordinates, energies, and other characteristics of the structures involved in the molecular process understudy. While most experienced users end up building scripts that dig throughout the output files searching for the relevant data, this is not the case for users without programming experience or time. Here we present an automated ESI generator supported by both web-based and command line interfaces. Focused on quantum mechanics calculations outputs so far, we trust that the community would find this tool useful. Source code is freely available at https://github.com/insilichem/esigen . A web app public demo can be found at http://esi.insilichem.com .