Yu. V. Tomilov

Kinetics of copper(II)-catalyzed cyclopropanation of olefins

Kinetics of the copper(II) acetylacetonate-catalyzed cyclopropanation of styrene and 2,5-dimethylhexa-2,4-diene is reported. A kinetic analysis of a catalytic olefin cyclopropanation scheme is suggested.

Acylation of spiro(1-pyrazoline-3,1′-cyclopropanes) to form 1-acyl-3-(2-chloroethyl)-2-pyrazolines and transformation of bicyclic 2-pyrazolines into 1,4,5,6-tetrahydropyridazines

Strained polycyclic spiro(1-pyrazoline-3,1′-cyclopropanes) react with acetyl or benzoyl chlorides at 0–15 °C regioselectively to give in high yields corresponding 1-acyl-3-(2-chloro-ethyl)-2-pyrazolines. Under the same conditions 6-ethenyl-4,5-diazaspiro[2,4]hept-4-ene gives a mixture of two pyrazolines resulting from the acyl group attack directed at different nitrogen atoms. Bicyclic pyrazolines-2 obtained by acylation of the cycloaddition products of diazocyclopropane with 3,3-disubstituted cyclopropenes transform under the action of hydrogen chloride to 1,4,5,6-tetrahydropyridazines in high yields.

Synthesis of substituted naphthalenes by GaCl3-mediated cross-dimerization—fragmentation of 2-arylcyclopropane-1,1-dicarboxylates

Substituted naphthalenes were obtained by treatment of a mixture of two different 2-arylcyclopropane-1,1-dicarboxylates with GaCl3 at 80 ℃. The process is accompanied by removal of the malonic moieties, naphthalene fragments being mainly formed from the arylcyclopropane, which is more prone to give the similar homocoupling product.

Reduction of substituted spiro[cyclopropane-3-(1-pyrazolines)] to spiro[cyclopropane-3-pyrazolidines] and 1-(2-aminoethyl)cyclopropylamine derivatives

Raney nickel-catalyzed hydrogenation of 5-substituted spiro[cyclopropane-3-(1-pyrazoline)]-5-carboxylates occurs with N—N bond cleavage with simultaneous cyclocondensation to give 3-aminopyrrolidin-2-ones containing a spirocyclopropane fragment. The presence of the second ester group in the pyrazoline side chain, in the position ensuring the formation of a five-membered ring results in 6,11-diazadispiro[2.1.4.2]undecane-7,10-dione, the product of double cyclocondensation of the intermediate diamine. Hydrogenation of the aryl-substituted spiro[cyclopropane-3-(1-pyrazolines)] in the presence of acetone affords hexahydrospiro[cyclopropane-4-pyrimidines], which can be converted into the cyclopropane-containing 1,3-diamines in the individual state or as salts.

Synthesis and chemical transformations of 2-cyclopropyl-2-diazoacetates

Methyl 2-cyclopropyl-2-diazoacetate was synthesized from acetylcyclopropane in few chemical steps in ∼55% total yield. Its copper or rhodium-catalyzed dediazoniation exclusively proceeds through the intramolecular isomerization of generated cyclopropyl(methoxycarbonyl)carbene to 1-methoxycarbonylcyclobutene, irrespective of the presence or the absence of unsaturated compounds. However, in the presence of acrylates or strained cycloalkenes, this diazo ester is being slowly involved into the 1,3-dipolar cycloaddition, giving cyclopropyl-substituted pyrazolinecarboxylates, which in case of 1-pyrazolines easily lose nitrogen molecule to selectively afford 1-cyclopropylcyclopropanecarboxylate derivatives.

Reactions of diazoalkanes with unsaturated compounds 15.* Catalytic reactions of unsaturated carbonyl compounds and their derivatives with diazomethane**

The present study concerned with the influence of the nature of the acetal fragment in unsaturated compounds on the reactivity of the C=C bond in cyclopropanation reactions with diazomethane catalyzed by copper and palladium compounds. The acetal substituents at the α- or γ-position with respect to the C=C bond were found to exert an activating effect on the yields of cyclopropanation products compared to the starting unsaturated carbonyl compounds, which give 1,3-dipolar cycloaddition adducts with CH2N2 as by-products. Cyclopropanation of the double bonds appeared to be most efficiently catalyzed by Pd(acac)2.

Thermal decomposition of strained spiro(1-pyrazoline-3,1′-cyclopropanes)

Pyrolysis (320–370 °C) of polycyclic 1-pyrazolines1 and2, obtained by 1,3-dipolar cycloaddition of diazocyclopropane to 3,3-dimethylcyclopropene and spiro[2,3]hex-1-ene, yields complex mixtures of isomeric hydrocarbons, substituted methylenecyclopropanes being the main components. Pyrolysis of 6-ethenyl- (4) and 6-methoxy-6-methylcarbonyl-4,5-diazaspiro[2,4]hept-4-enes (6) at 310–320 °C proceeds more unambiguously to give vinyl- (18) and 1-methoxy-1-methylcarbonylspiropentanes (20) in ∼85 and 95 % yields with respect to the transformed pyrazolines. Dediazotization of pyrazoline3 obtained from diazocyclopropane and benzvalene requires more drastic conditions (−440 °C) and produces indane.

Analysis of content of (–)-secoisolariciresinol and related polyphenols in different morphological parts and anatomical structures of larch wood from Siberia

Productive efficiency of technology of polysaccharide and lignin manufacturing from wood raw materials can be significantly improved by integration of purification stages of low molecular weight wood components widely used in applied chemistry into the technological cycle. In this connection, phenols including lignans and flavonoids, which have a practical application potential, are of a special interest. In the present work the results of a study of the content of (–)-secoisolariciresinol, dihydroquercetin and related polyphenols in different morphological parts and anatomical structures of larch wood from the Siberia are analyzed. Analysis of the content of the listed products by reversed-phase HPLC provides the selection of optimal raw material for organizing the manufacture of the listed compounds with predictable efficiency. Increased content of (–)-secoisolariciresinol (up to 3—4%) observed in wood of the trunk knot areas of larch from Khakassia evidences the prospects of raw material processing in this region for production of (–)-secoisolariciresinol from the wastes of larch wood refinery.

Cascade reactions of nitrogen- and phosphorus-containing ylides with methyl diazoacetate and in situ generated diazocyclopropane

Reactions of pyridinium or phosphorus ylides with diazo esters are multistep processes. The first step is covalent bonding between the ylide C atom and the terminal N atom. This is followed by elimination of the ylide-forming molecule and successive addition of one or two ylide fragments. Depending on the nature of the starting reagents, this type of transformations leads to novel polyfunctional phosphorus ylides or, with pyridinium ylides, to polyalkyl 3,4(4,5)-diazaalkadienetri-or tetracarboxylates. A reaction of the in situ generated diazocyclopropane with methyl triphenylphosphoranylideneacetate stops at the first step, giving a cyclopropylazo-containing ylide. Reactions of the latter with acyl chlorides yield six-membered heterocyclic betaines with a triphenylphosphonium substituent.

One-step synthesis of substituted 3,5-dinitropiperidines and 1,5-dinitro-3,7-diazabicyclo[3.3.1]nonanes from 1,3-dinitropropanes

Abstract1,5-Dinitro-3,7-diazabicyclo[3.3.1]nonane derivatives were synthesized in up to 83%yields by the Mannich reaction of 1,3-dinitropropanes with excess formaldehyde and primary amines. In some cases, for instance, when 2,2-dimethyl-1,3-dinitropropane and benzylamine or monoethanolamine are used, the reaction occurs with low yields or stops at the step of formation of 3,5-dinitropiperidines. The influence of the structure of the starting compounds and reaction conditions on the yields of 1,5-dinitro-3,7-diazabicyclo[3.3.1]nonanes and 3,5-dinitropiperidines was studied.