Unusual Regioselective Electrophilic Substitutions in Quinoline Foldamers: Conceptual DFT and Frontier Molecular Orbital Analysis Reveal the Crucial Role of Folding and Substituents

Friedel-Crafts Reaction of N,N-Dimethylaniline with Alkenes Catalyzed by Cyclic Diaminocarbene-Gold(I) Complex

In general, Friedel-Crafts reaction is incompatible with amines due to the Lewis acidity of the catalysts. Recently, we reported that cyclic diaminocarbene-Gold(I) can be used as catalyst for the Friedel-Crafts alkylation between aromatic amines and alkenes. Herein, a systematically theoretical research was performed on this rare Friedel-Crafts reaction. The adopted calculation method is accurate enough to reproduce the crystal structure of the catalyst. It was found that the reactions followed the electrophilic aromatic substitution mechanism. The gold cation can activate the C=C double bond and generate the electrophilic group which can be attacked by the aromatic ring. The para-product is more energy favorable which agrees well with the experimental results. The reaction of α-methylstyrene follows the Markovnikov rule, and the activation energy to generate the branched product of methylstyrene is lower than that producing the linear product. However, the reaction of butanone follows the anti-Markovnikov rule, and the activation energy to generate the branched product of butanone is higher than that producing the linear product. These calculation results reveal the mechanism of this new Friedel-Crafts reaction. It can well explain the high para-selectivity and the substrate-dependent of the product structures in the experiment.

Supramolecular catalysis in the methylation of meta-phenylene ethynylene foldamer containing N,N-dimethylaminopyridine

DFT investigations show that the methylation reaction of N,N-dimethylaminopyridine (DMAP)-modified meta-phenylene ethynylene foldamer can be catalyzed by the noncovalent interactions between the foldamer and the methyl sulfonate esters.

Theoretical study on the mechanism of selective fluorination of aromatic compounds with Selectfluor

The selective fluorination of aromatic compounds with Selectfluor has been studied theoretically. Our calculations indicate that the fluorine bond contributes to the stabilization of the π complexes, and the SET mechanism is preferred over the S_N2 mechanism.