Reaction of diazoalkanes with unsaturated compounds

A THF solution of diazopropyne was obtained in 60% yield by the reaction of a 30% aqueous solution of methylamine withN,N′-dinitroso-N,N′-dipropargylterephthalodiamide. The reactions of diazopropyne with methyl acrylate and methyl methacrylate giving various ethynylpyrazolines as well as its CuCl-catalyzed decomposition in the presence of norbornene or norbornadiene yielding ethynylcyclopropanes were studied. The main products of catalytic deazotization of diazopropyne in the absence of unsaturated compounds are isomericE- andZ-hex-3-ene-1,5-diynes resulting from propargylene dimerization. For Part 12, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2278–2282, November, 1998.     

Reaction of tetrafluorohydrazine with oximes

Conclusions Reaction of tetrafluorohydrazine with dimethylglyoxime, acetaldoxime, and p-nitrosophenol gave the corresponding N-fluoroazoxy derivatives. Some special features of the process were investigated.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 719–720, March, 1970.     

Reaction of unsaturated compounds with diazoalkanes. Communication 3. Cyclopropanation of cyclooctatetraene with diazomethane

Conclusions The cyclopropanation of the double bonds in cyclooctatetraene by diazomethane in the presence of cuprous chloride is nonregioselective and leads to the formation of the corresponding mono-, di-, tri-, and tetracyclopropanation products with yields determined by the amount of added diazomethane. The obtained bis-, tris-, and tetrakishomocyclooctatetraenes are characterized by a preference for the isomers with the exo orientation of the cyclopropane fragments.For Communication 2, see [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 77–84, January, 1986.     

Reaction of selenobenzophenones with olefins. Formation of 1H-2-benzoselenopyrans. Reaction of 1H-2-benzoselenopyrans with diazoalkanes

Selenobenzophenone reacts as a diene with dimethyl acetylenedicarboxylate (DMAD) to lead to dimethyl 1H-1-diphenylmethyl-1-phenyl-2-benzoselenopyran-3,4-dicarboxylate (5c) in moderate yield; the initial [4 + 2] cycloaddition is followed by the addition of another 1 mol equiv of selenobenzophenone. The reaction might proceed through carbene insertion of the primary cycloadduct. On the other hand, 4,4'-dimethoxyselenobenzophenone combines as a diene with DMAD furnishing dimethyl 1H-1-p-methoxyphenyl-6-methoxy-2-benzoselenopyran-3,4-dicarboxylate (4a). The reaction of benzoselenopyran derivative (4) with diaryldiazomethanes afforded another type of carbene insertion product.     

Reaction of diazoalkanes with unsaturated compounds. 9 Catalyzed cyclomethylenation of trimethylsilylacetylenes by diazomethane

The catalyzed reaction of methyl-, propyl-, and cyclopropyltrimethylsilylacetylenes with diazomethane in the presence of CuCl leads to the corresponding cyclopropenes and bicyclobutanes with overall yields of up to 70%, and also to the products of incorporation of a methylene group into the C³-H bond of the cyclopropenes formed (2–9%). Partial catalyzed isomerization of the 1-trimethylsilyl-2-cyclopropylcyclopropene formed from trimethylsilylcyclopropylacetylene, into 1-trimethylsilyl-1-cyclopropylallene (yield 50%) was discovered to proceed under the reaction conditions.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1141–1146, May, 1990.     

Reaction of carbonyl compounds with diazoalkanes as a method for epoxide synthesis. A review

The application of the reaction of carbonyl compounds with diazoalkanes the preparation of epoxides is reviewed. The effects of the structures of the reagent and substrate and of the solvent on the reaction course and product yield are examined. The stereochemistry of epoxide formation is discussed.Belorus State Technological University, 220630 Minsk. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 291–309, March, 1995. Original article submitted July 29, 1994.     

Reaction of diazoalkanes with unsaturated compounds. 10. 1,3-Dipolar cycloaddition of diazocyclopropane to strained cycloalkenes

The reaction of diazocyclopropane, generated in situ by alkaline hydrolysis of N-nitroso-N-cyclopropylurea at –20 to –40C, with the double bond of norbornene hydrocarbons or 3,3-dimethylcyclopropene is a 1,3-dipolar cycloaddition and affords 45–70% yields of thermally stable 1-pyrazolines possessing a spiro-joined cyclopropane fragment. Methylenecyclopropane under the same conditions is a less effective and selective interceptor of diazocyclopropane, forming in 10% yields not only isomeric 1-pyrazolines but the corresponding product of cyclopropylization, dispiro[2.0.2.1]heptane.For previous communication, see [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1057–1062, May, 1991.     

Reaction of diazoalkanes with unsaturated compounds Communication 1. Cyclopropanation of olefins with diazomethane in the presence of copper compounds

Conclusions In the presence of CuCl or (PhO)3P·CuCl diazomethane cyclopropanates cycloalkenes and cyclodienes with various different structures. When this is done the yields of the cyclopropane compounds increase as the size of the ring and its degree of conjugation increases. This is in accord with the change in the stability of the copper complexes of these olefins which are formed under the reaction conditions.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 119–124, January, 1984.Results partially presented at the Twelfth Mendeleev Congress on General and Applied Chemistry in Baku [1].     

Reaction of 3-trimethylsilylprop-2-ynal with α-hydroxyamino oximes

3-Trimethylsilylprop-2-ynal reacted with aliphatic α-hydroxyamino oximes in a chemoselective fashion at the aldehyde group to give hitherto unknown open-chain 3-trimethylsilylprop-2-yn-1-ylideneamine oxides. The possibility for intramolecular hydrogen bonding with participation of OH, C≡C, and N→O groups in the products was studied by IR spectroscopy.     

Reaction of diazoalkanes with unsaturated compounds. 11. Relative reactivity of olefins on catalytic cyclopropanation with diazomethane and palladium catalysts

The relative reactivity of unsaturated compounds on catalytic cyclopropanation with diazomethane in the presence of catalysts based on Pd²⁺ [Pd(OAc)₂, Pd(acac)₂, (PPh₃)₂·PdCl₂] has been studied using competing reactions. An interconnection was shown between the relative reactivity of the olefins and the coordinating activity of the C=C bond depending on its strain and spatial environment.For previous communication, see [1].Institute of Organic Chemistry, Urals Branch, Russian Academy of Sciences, 450054 Ufa; N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 10, pp. 2353–2361, October, 1992.     

Asymmetric synthesis of aminoacids by catalytic reduction of azlactones by substituted acylaminoacrylic acids. 19. Reaction of catalyst with substrate

Conclusions Reaction of 2-methyl-4-benzylideneoxazol-5-one with a zerovalent palladium complex containing S-(-)--phenylethylamine as ligand, in chloroform or dichloromethane as solvent, gives a heteroligand complex which is a reactive intermediate in reductive aminolysis,Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2283–2286, October, 1987.The authors thank E. S. Shpiro for obtaining and discussing the PES-spectra.     

Reaction of Z isomers of alkylaromatic 1,2-hydroxylamino oximes with 1,2-diketones

The reactions of Z isomers of alkylaromatic 1,2-hydroxylamino oximes containing the hydroxylamino group at the primary or secondary carbon atom with diacetyl afford 6-acetyl-5,6-dihydro-4H-1,2,5-oxadiazines. The reactions of these compounds with alkylaromatic 1,2-diketones produce N-substituted α-aroylnitrones or 6-aroyl-5,6-dihydro-4H-1,2,5-oxadiazines or, alternatively, their tautomeric mixtures. Dedicated to the memory of Academician V. A. Koptyug on the occasion of the 75th anniversary of his birth. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1008–1013, June, 2006.     

1,3-dipolar cycloadditions of diazoalkanes to activated sulfoxides: influence of Lewis acids

[reaction: see text] The reactions of diazomethane and diazoethane with (S)-3-p-tolylsulfinylfuran-2(5H)-one (3) and its 4-methyl derivative (4) have been studied. The sulfinyl group was able to completely control the pi-facial selectivity of all these reactions, which decreased when the polarity of the solvent increased and could be inverted in the presence of Lewis acids, Yb(OTf)(3) being the most efficient catalyst. This behavior made possible the stereodivergent synthesis of diastereoisomeric pyrazolines in almost quantitative yields and de's higher than 98%. The endo/exo selectivity was also complete in reactions of 3 with diazoethane, whereas 4 afforded an easily separable 1:1 mixture of diastereoisomers. Steric factors accounts for the endo/exo selectivity, whereas electrostatic interactions must also be considered to explain the facial selectivity.