Sergei A. Belyakov

THE PREPARATION OF FUNCTIONALIZED AMINES AND AMIDES USING BENZOTRIAZOLE DERIVATIVES AND ORGANOZINC REAGENTS

Abstract Secondary and tertiary amines 6 are conveniently prepared in good yields by reacting organozinc halides with adducts 4, which are derived from the corresponding amines, aldehydes and benzotriazole. The use of organozinc reagents enables the introduction of nitro, cyano or ester functionalities into amine mainframes. This methodology was also used to prepare functionalized amides 8.

POLYMER-SUPPORTED PREPARATION OF SUBSTITUTED PHENOLS : A NEW EXAMPLE OF SIMULTANEOUS CYCLIZATION-CLEAVAGE REACTION ON SOLID PHASE

Abstract A series of variously substituted phenols was synthesized in high yields using the “cyclization-cleavage” approach. Base-catalyzed reactions between α,β-unsaturated ketones and polymer-bound acetonyl groups result in a tandem Michael addition/annulation reaction followed by elimination and rearrangement into phenols. Since all intermediates are on the resin until the last stage, the final reaction products contain only the desired phenols with the starting ketones as minor impurities. This efficient one-pot aromatic ring formation represents a new variant of solid phase synthesis.

α-(Benzotriazolyl)methyl phenyl thioethers: Convenient reagents for α-phenylthioalkylation of silylated nucleophiles

Abstract Stable, crystalline α-(benzotriazolyl)methyl phenyl thioethers ( 1 ), easily prepared from carbonyl compounds, thiophenol and benzotriazole, are convenient reagents for the phenylthiomethylation of trimethylsilyl cyanide, trimethylallylsilane, and trimethylsilyl enol ethers to afford the corresponding substituted thioethers and β-phenylthioalkylketones ( 3 ) in good yields.

Preparation of spin-labeled styrene-divinylbenzene copolymers and a new approach for quantitative determination of the resin loading using ESR spectroscopy

Abstract Several spin-labeled car☐yl-containing resins were prepared, containing different concentrations of spin labels (nitroxyl or verdazyl stable free radicals). ESR studies of the prepared resin specimens demonstrated that the dependence between their ESR signal area and estimated and/or calculated amount of attached spin labels is linear in the case of verdazyl radicals, which makes this non-destructive approach a promising fast and accurate method for a resin loading determination.

The Direct Carbamoylation of Organometallic Reagents with 1,2,3-Benzotriazole-1-carboxamides

Various (hetero)aromatic amides are synthesized efficiently by the carbamoylation of organometallic reagents.

NEW PODANDS WITH TERMINAL CHROMOGENIC MOIETIES DERIVED FROM FORMAZANS

Synthesis of several new podands, bearing various terminal chromophoric functions of formazan (9–11), verdazyl (18–20) and verdazylium salt (21–23) types and having a different length of oligooxyethylene bridge between chromophoric units, is developed. Calculated (Alchemy-2000) and found (EPR data) distances between spin centers in bis-radicals 18–20 correlate well. Such spin-labeled species could be good models for the EPR study of host–guest interactions involving ethylene glycol-based podands.

Novel Synthesis of α-Benzotriazolyl-substituted Ketones†

Silyl enol ethers react with 1-chlorobenzotriazole to provide a new general method for the preparation of α-benzotriazolyl-substituted ketones.