Triflic Acid-Mediated Condensation of Phthalimide with Diaryl Ethers as a Route to Spiro-Isoindolinones: Mechanistic Insights and Related Reactions.

Phthalimide and -phenylphthalimide smoothly condense with di--tolyl ether in triflic acid (CFSOH, TfOH) to obtain the corresponding spiro[isoindoline-1,9'-xanthen]-3-ones. Structural analogs of phthalimide, such as phthalic anhydride and 1,3-indandione (but not saccharin), show similar reactivity. In contrast, N-(tetrafluoropyridin-4-yl)phthalimide reacts with DTE by an alternative pathway, yielding isobenzofuran dispiro derivative.

Redox Transformations of the OX063 Radical in Biological Media: Oxidative Decay of Initial Trityl with Further Formation of Structurally-Modified TAM.

Being a low-toxic and hydrophilic representative of TAM, OX063 has shown its suitability for in-vivo and in-cell EPR experiments and design of spin labels. Using C labeling, we investigated the course of oxidative degradation of OX063 into quinone-methide (QM) under the influence of superoxide as well as further thiol-promoted reduction of QM into TAM radical, which formally corresponds to substitution of a carboxyl function by a hydroxyl group. We found these transformations being quantitative in model reactions mimicking specific features of biological media and confirmed the presence of these reactions in the blood and liver homogenate of mice in vitro.

Halide Complexes of 5,6-Dicyano-2,1,3-Benzoselenadiazole with 1 : 4 Stoichiometry: Cooperativity between Chalcogen and Hydrogen Bonding.

The [M -Hal] (M=the title compound; Hal=Cl, Br, and I) complexes were isolated in the form of salts of [Et N] cation and characterized by XRD, NMR, UV-Vis, DFT, QTAIM, EDD, and EDA. Their stoichiometry is caused by a cooperative interplay of σ-hole-driven chalcogen (ChB) and hydrogen (HB) bondings. In the crystal, [M -Hal] are connected by the π-hole-driven ChB; overall, each [Hal] is six-coordinated.

Cluster halogenation of adamantane and its derivatives with bromine and iodine monochloride.

Noncatalytic halogenation of adamantane (AdH) with bromine or iodine monochloride was found to proceed according to the cluster mechanism featuring high kinetic order with respect to the halogen and a sharp decrease in the calculated energy barrier when additional halogen molecules are involved in the quantum chemical system. In the reaction with Br, 1-AdBr formed selectively. This reaction proved to be first order in terms of AdH and approximately seventh order in Br, and its rate does not depend on the rising concentration of HBr.

DFT insights into superelectrophilic activation of α,β-unsaturated nitriles and ketones in superacids.

Superelectrophilic activation of α,β-unsaturated carbonyl compounds and their isoelectronic analogs, proceeding normally under superacidic conditions, have led to a great variety of beneficial synthetic transformations. However, the essence of such activation is not yet fully recognized, while a number of alternative views on the subject have been discussed at length in the literature. Here, taking the example of virtual reactions of cinnamonitrile and benzalacetone with benzene, their feasible mechanistic variants, including multiple protonation (coordination to AlCl) of the reactants, were analyzed based on density functional theory (DFT).