Five-membered 2,3-dioxoheterocycles: LVIII. Reaction of methyl 1-Aryl-3-aroyl-4,5-dioxo-4,5-dihydro-1H-pyrrol-2-carboxylates with substituted 1-methyl-3,4-dihydroisoquinolines. New approach to the synthesis of steroid 13-azaanalogs

Methyl 1-aryl-3-aroyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates reacted with substituted 1-methyl-3,4-dihydroisoquinolines with the formation of substituted 3-oxo-2,3,5,6-tetra-hydropyrrolo[2,1-a]-isoquinoline-2-spiro-2′-(1-aryl-3-aroyl-4-hydroxy-5-oxo-2,5-dihydro-1H-pyrroles). A new approach was developed to the synthesis of 13-azagonanes, substituted benzo[f]pyrrolo[2,1-a]isoquinoline-9-spiro-2′-pyrroles.     

Nitrogen heterocycles from trimethylbenzenes

The reaction between 1,2,4‐trimethylbenzene 1 , isobutyric aldehyde, and cyanoacetic ester afforded a mixture of three products: 3,3,5,6,8‐ pentamethyl‐1,2,3,4‐tetraisoquinolylidene‐1‐acetic acid ether ( 2 ) and its 3,3,5,6,7‐pentamethyl‐( 3 )‐ and 3,3,6,7,8‐pentamethyl‐1,2,3,4‐tetraisoquinolyli‐ dene‐1‐acetic acid ether isomers ( 3 ) in ratio 1:5:1. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:471–476, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20045     

Fractals of graphene quantum dots in photoluminescence of shungite

Viewing shungite as loosely packed fractal nets of graphene-based (reduced graphene oxide, rGO) quantum dots (GQDs), we consider photoluminescence of the latter as a convincing proof of the structural concept as well as of the GQD attribution to individual rGO fragments. We study emission from shungite GQDs for colloidal dispersions in water, carbon tetrachloride, and toluene at both room and low temperatures. As expected, the photoluminescence of the GQD aqueous dispersions is quite similar to that of synthetic GQDs of the rGO origin. The morphological study of shungite dispersions shows a steady trend of GQDs to form fractals and to drastically change the colloid fractal structure caused by the solvent exchange. Spectral study reveals a dual character of the emitting centers: individual GQDs are responsible for the spectra position while the fractal structure of GQD colloids ensures high broadening of the spectra due to structural inhomogeneity, thus causing a peculiar dependence of the photoluminescence spectra on the excitation wavelength. For the first time, photoluminescence spectra of individual GQDs were observed in frozen toluene dispersions, which paves the way for a theoretical treatment of the GQD photonics.     

Direct heterocyclization of benzocrown ethers

The synthesis of novel 3,3‐dialkyl‐3,4‐dihydroisoquinoline derivatives via direct heterocyclization of benzocrown ethers is described. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:192–195, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20092     

Quantum chemical calculation of hydration for alkali metal salts

Calculations using the GAUSSIAN 03 program package were performed to determine the hydrated structures of lithium, potassium, LiCl, NaCl, and sulfonic cation exchanger in the form of alkali metal ions. For ions with positive hydration, the distance between the radii of the first and second spheres of hydration water is larger than in pure water; for ions with negative hydration, this distance is smaller. Salts with different types of hydration for cation and anion have hydrated structures similar to those of ions with negative hydration.     

Reaction of 2-alkylaminobenzothiazoles with acrylic acid

The behavior of 2-alkylaminobenzothiazoles in the reaction with acrylic acid was studied and it was shown that under kinetically controlled conditions, the reaction proceeds at the endocyclic nitrogen atom of the ambifunctional system. The formation of amino-isomers is controlled thermodynamically.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 986–991, July, 1986.     

Synthesis of 4′H-spiro[adamantane-2,3′-isoquinoline] derivatives

Russian Journal of Organic Chemistry -     

Electrochemical initiation by sulfur dioxide of radical-chain trifluoromethylation processes of thiophenols with bromotrifluoromethane

Sulfur dioxide may serve as an efficient catalyst for the electrochemical trifluoromethylation of thiophenols by Freon F13B1 (CF₃Br), which enables implementation of trifluoromethylation in an energy-saving radical-chain regime.