Nucleophilic Opening of the Aziridine Ring in 1-Alkyl-1-azoniatricyclo[2.2.1.02,6]heptanes

Opening of the aziridine ring in 3-bromo-1-alkyl-1-azoniatricyclo[2.2.1.02,6]heptane bromides by the action of various nucleophiles leads to formation of the corresponding 6-substituted 2-alkyl-2-azabicyclo[2.2.1]heptanes.     

Addition of bromine to 2-methyl-2-azabicyclo[2.2.1]hept-5-ene

Addition of bromine to 2-methyl-2-azabicyclo[2.2.1]hept-5-ene was studied. Unexpectedly, 3-bromo-1-methyl-1-azoniatricyclo[2.2.1.0^2,6]heptane tribromide was isolated rather than the product of bromine addition to the double bond. The former reacted with the starting alkene in a polar solvent to form the corresponding monobromide.     

Synthesis of New 2,3-Dihydroindole Derivatives and Evaluation of Their Melatonin Receptor Binding Affinity

2,3-Dihydroindoles are promising agents for the synthesis of new compounds with neuroprotective and antioxidant properties. Usually, these compounds are obtained by direct reduction of the corresponding indoles containing acceptor groups in the indole ring for its activation. In this work, we propose a synthetic strategy to obtain new 2,3-dihydroindole derivatives from the corresponding polyfunctional 2-oxindoles. Three methods were proposed for reduction of functional groups in the 2-oxindole and 2-chloroindole molecules using various boron hydrides. The possibility of chemoselective reduction of the nitrile group in the presence of an amide was shown. The proposed synthetic strategy can be used, for example, for the synthesis of new analogs of the endogenous hormone melatonin and other compounds with neuroprotective properties.     

Synthesis of 1,3,5-tribromo- and triiodophloroglucinol tris(triflates)

A method for the preparative synthesis of 1,3,5-tribromophloroglucinol and 1,3,5-triiodophloroglucinol tris(triflates) was suggested. This synthesis was shown to be extremely sensitive to reaction temperature conditions.     

Halogenation of 2-alkyl-2-azabicycloalkenes as a method for the synthesis of stable aziridinium salts of a new class

Addition of bromine and potassium dihaloiodates(i) to 2-alkyl-2-azabicyclo[2.2.1]hept-5-enes and 2-alkyl-2-azabicyclo[2.2.2]oct-5-enes affords quaternary ammonium salts containing the aziridine ring and the polyhalide anion. The possibility of using these salts for the synthesis of 6-substituted 2-alkyl-2-azabicyclo[2.2.1]heptanes has been shown.     

Homocoupling of bromotriazole derivatives on metal complex catalysts

Russian Chemical Bulletin - Homocoupling of 4-bromo-1,2,3-triazoles upon treatment with stoichiometric amount of bis(pinacolato)diboron on a palladium catalyst gives 4,4´-bi-1,2,3-triazoles in...     

Stereoselective synthesis of highly substituted 8-oxabicyclo[3.2.1]octanes and 2,7-dioxatricyclo[4.2.1.03,8]nonanes

The synthesis of new polyhydroxylated 8-oxabicyclo[3.2.1]octanes and 2,7-dioxatricyclo[4.2.1.0^3,8]nonanes is described. These structures is an interesting synthetic blocks for potential bioactive molecules. The precursor, 3-chloro-8-oxabicyclo[3.2.1]oct-6-ene-2,4-dione was obtained from reaction of tetrachlorocyclopropene with furan, then it was involved in carbonyl groups reduction and double bond oxidation, resulted in the formation of a polyhydroxylated derivatives, differently substituted at C-3 position, with five new stereocenters.Using intramolecular transannular hydroxycyclization, bicyclic epoxy diacetate was transformed into 2,7-dioxatricyclo[4.2.1.0^3,8]nonane in high yield through an alkoxide intermediate. Compounds thus obtained have a structure close to certain molecules with antitumor and glycosidase inhibitors activity.     

Electrophilic addition to norbornene derivatives containing CF<Subscript>3</Subscript> and NO<Subscript>2</Subscript> groups

Electrophilic sulfenylation, selenenation, and halogenation of bicyclo[2.2.1]heptenes containing CF₃ or NO₂ group in position endo-5 were studied. The sulfenylation and selenenation were accomplished by arylsulfene- and arylselenenamides activated by POHal₃ (Hal = Br, Cl), and iodination was performed by KICl₂. The reactions are regiospecific and involve an exo-attack of the electrophilic fragment (arylthio or arylseleno group or iodine) on the C=C bond atom located closer to the CF₃ or NO₂ group. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1445–1448, June, 2005.     

Molecular and crystal structure of 3,7-di(2-propenyl)-1,5-diphenyl-3,7-diazabicyclo[3.3.1]-nonan-9-one complexed with copper(II) chloride

We have investigated the molecular and crystal structure of 3, 7-di(2-propenyl)-1, 5-diphenyl-3, 7-diazabicyclo[3.3.1]nonan-9-one complexed with copper(II) chloride. We have shown for the first time that the reason for the distortion of the coordination polyhedron of the metal is the interaction of the substituents at the nitrogen atoms with the halogen atoms.Communication 2 in the series Complexing properties of 3,7-diazabicyclo[3.3.1]nonanes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 770–774, June, 1996. Original article submitted April 13, 1996.Deceased.