A theoretical study on platinum-catalyzed cycloisomerization of 2-ethynyl-1-ferrocenylbenzene

Pt(ii)-Chiral diene-catalyzed enantioselective formal [4 + 2] cycloaddition initiated by C–C bond cleavage and elucidation of a Pt(ii)/(iv) cycle by DFT calculations

A Pt(ii)-chiral diene complex demonstrates a high catalytic activity in the enantioselective formal [4 + 2] cycloaddition along with C–C bond cleavage of biphenylene at room temp. DFT calculations elucidated that the present catalysis involves a rare Pt(ii)/Pt(iv) cycle.

Theoretical study of rhodium(III)-catalyzed synthesis of benzoxepine and coumarin

The mechanisms of the rhodium-catalyzed cycloaddition of 2-vinylphenol with diphenylacetylene and carbon monoxide have been studied using density functional theory calculations at the B3LYP/6-31G (d, p) (Lanl2dz for Rh) level of theory. The SMD solvation model was used in MeCN solvents at M06-2X/6-311 ++ G (d, p) (Lanl2dz (f) for Rh) levels using a single-point calculation to consider the solvent effect. The calculation results show that there are two competitive reaction pathways for the cycloaddition reaction of rhodium-catalyzed synthesis of benzohexine and coumarin. Starting from the precursor reaction complex, the reaction channel is more favorable for the carbon atoms of diphenylacetylene and carbon monoxide to attack the Rh-C bond (the barriers of 9.88 and 10.01 kcal/mol) rather than attack the Rh-O bond (the barriers of 15.37 and 30.17 kcal/mol), and carbon monoxide in two different reaction channels has a greater energy difference than diphenylacetylene. The results show that the computational study of the rhodium-catalyzed cycloaddition reaction has a high catalytic activity consistent with the high yield of the experiment of Gulías et al.

Theoretical study on reaction mechanism of synthesis of iridium complexes having cyclometalated acyclic diaminocarbene ancillary ligands

DFT calculations at the M06-2X level were performed to explore the reaction mechanism for the synthesis of the new cyclometalated iridium(III) complexes with acyclic diaminocarbene ancillary ligands. The solvent effects of the reaction systems have been considered by a single-point energy calculation using the SMD model in the experimental conditions of CH₂Cl₂ solvent. The calculated results show that the reaction consists of two main steps: the first step is the hydrogen transfer between the two N atoms, and the next step is the closed-loop process of the Ir atom and the aromatic ring ortho to release the HCl molecule. The reaction has a relatively low activation free energy of 17.1-23.2 kcal mol^-1, indicating that it is easy to occur under the experimental conditions of Na et al. At the same time, it was found that the aryl para-CF₃ substituent has higher reactivity than the corresponding reactant of the NO₂ substituent.