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The work reports the theoretical investigation of the mechanism and regioselectivity of the Pd(OAc)-catalyzed hydrothiolation of heteroatom-substituted alkenes with benzenethiol leading to Markovnikov-type product. The reaction process includes: (1) activation of the S-H bond for benzenethiol by the catalyst Pd(OAc); (2) migratory insertion of the alkenes bearing heteroatoms into the Pd-S bond; (3) AcOH molecule attacks Pd-C bonds to give the product and release the catalyst. In addition, the computed results shown that Pd(OAc)-catalyzed hydrothiolation take place by two possible channels and get anti-Markovnikov-type or Markovnikov-type species. The Markovnikov-type reaction channel is more favored with the energy barriers of 21.9-25.6 versus 28.5-31.2 kcal/mol for the anti-Markovnikov-type pathway. The theoretical results and the experimental observations of Tamai and co-workers are consistent. This reaction would proceed in mild conditions and afford the Markovnikov-type products in high yields and regioselectivity. [ABSTRACT FROM AUTHOR]

A theoretical investigation of the [3+2] cycloaddition reaction of the NHC-boryl azide with alkynes and nitriles has been presented by using the DFT (B3LYP) method. Solvent effects on these reactions have been explored by calculation that included a polarizable continuum model (PCM) for the solvent (CH). The title reaction could produce two different five-membered products (1,4-regioisomer and 1,5-regioisomer). The reaction pathway involves a one-step mechanism through a [3+2] addition where two nitrogen atoms of the N-heterocyclic carbene boryl azide adds to the C≡A (A=C or N) bond to form two new C-N or N-N bonds. For alkynes, the reactions can take place more easily to give 1,4-regioisomer product, while the reactions proceed for nitriles along the 1,5-regioisomer pathway. The reaction systems have high chemical reactivity with low barriers and could be favored. The calculations indicated that the cycloaddition reaction of alkynes and nitriles has the better regioselectivity. Our computational results are good consistent with the experimental observations of Merling and co-workers for [3+2]-dipolar cycloaddition reaction of N-heterocyclic carbene boryl azide. [ABSTRACT FROM AUTHOR]

The adsorption mechanism of a series of macroporous adsorption resins ( p-(CHNH)PhL (L = NH, OH, COOH)) with rutin have been investigated using density functional theory calculations at B3LYP/6-31G(d,p) level of theory. Solvent effects on these species were explored using calculations that included a polarizable continuum model for the aqueous solvent. In this article, the geometry structure, interaction energies and the infrared spectra for the stable reactants and the adsorption complexes were obtained and analyzed. The results show that the hydrogen-bonding have been formed in the adsorption complexes. The higher interaction energy is calculated for the carboxyl group, while the resin with amino group has the highest adsorption capacity for rutin. The adsorption complexes become more and more stable as increasing the number of adsorbents. Our theoretical study is in good explanation for the experimental results. [ABSTRACT FROM AUTHOR]