Amidation of deltacyclene and hexacyclic norbornadiene dimers with acetonitrile and water catalyzed by FeCl3·6H2O

Abstract

FeCl₃·6H₂O-catalyzed Ritter amidation of deltacyclene and hexacyclic norbornadiene dimers containing both a double bond and a three-carbon ring in the molecule with acetonitrile and water was performed. Depending on the hydrocarbon structure, the reaction proceeds via C-C bond cleavage in the three-carbon ring or at the double bond to form the corresponding N-acetamides.     

1,3-Migration of a phenyl group in the conversion of (Me3Si)2(PhMe2Si)CSiMePhX into (Me3Si)2(Ph2MeSi)CSiMe2Y species

The finding that compounds of the type (Me₃Si)₂(PhMe₂Si)CSiMePhX react with electrophiles to give very predominantly rearranged products (Me₃Si)₂(Ph₂MeSi)CSiMe₂Y, which would be expected to be thermodynamically disfavoured, can be rationalized in terms of a mechanism in which the anchimerically-assisted departure of X⁻ gives the Ph-bridged cation [(Me₃Si)₂

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MePh]⁺ which is attacked by the nucleophile at the less hindered centre bearing two Me groups rather than that bearing one Me and one Ph group, with the outcome determined by kinetic rather than thermodynamic factors. Both (Me₃Si)₂(Ph₂MeSi)CSiMe₂Br and its isomer (Me₃Si)₂(PhMe₂Si)CSiMePhBr react with AgBF₄ in CH₂Cl₂ or Et₂O to give >95% of the fluoride (Me₃Si)₂(Ph₂MeSi)CSiMe₂F. Reaction of the bromide (Me₃Si)₂(PhMe₂Si)CSiMePhBr with AgO₂CCF₃ in Et₂O, and that of the hydride (Me₃Si)₂(PhMe₂Si)CSiMePhH with ICl in CCl₄, likewise give >95% of the rearranged (Me₃Si)₂(Ph₂MeSi)CSiMe₂O₂CCF₃ and (Me₃Si)₂(Ph₂MeSi)CSiMe₂Cl, respectively.     

Synthesis of 6,9-Dipropyl-1,4-Dioxaspiro[4.5] Deca-6,8-Diene-2,10-Dione and its Diels-Alder Reactions with Substituted Acetylenes

The title compound, a masked 3,6-di-n-propyl-o-benzoquinone, was synthesized from 3,6-di-n-propylcatechol in 82% yield. Its Diels-Alder reactions with methyl propiolate, phenylacetylene, 1-octyne, dimethyl acetylenedicarboxylate, diphenylacetylene and 3-hexyne were studied. The yields of the adducts were excellent except for the last two cases in which the unimolecular decomposition of the title compound to generate 3,6-di-n-propylcatechol methylene ether predominates. The regiochemistry of the adducts derived from monosubstituted acetylenes were determined by the correlation of ¹³C chemical shifts of the adducts and the corresponding bicyclo[2.2.2]octa-5,7-diene-2,3-diones obtained from the hydrolysis of the spirolactone ring of the Diels-Alder adducts. Photolysis of these α-diketones gave the corresponding aromatic compounds in high yields. These synthetic sequences provide an effective entry to bicyclo[2.2.2]octa-5,7-diene-2,3-diones and polysubstituted benzene derivatives.     

阳离子改性HZSM-5沸石上低碳醇反应历程的TPSR-MS研究

用ＴＰＳＲ－ＭＳ技术研究了Ｃｕ，Ｚｎ和Ｇａ改性Ｈ－ＺＳＭ－５沸石的活性中心性质及Ｃ１～Ｃ４醇的反应历程。结果表明，Ｚｎ－和Ｇａ－ＺＳＭ－５有两种芳构化活性中心，即Ｂ酸和Ｚｎ，Ｇａ活性物种；甲醇在Ｃｕ－ＺＳＭ－５上只生成二甲醚、ＣＯ和ＣＯ２，而在Ｚｎ－ＺＳＭ－５上芳构化反应历程为：（１）醇经由醚脱水生成烯烃，Ｃ２～Ｃ４醇学可单分子脱水生成烯烃；（２）烯烃中间物齐聚，齐聚物通过氢转移和脱氢途径环化、芳     

Reaction of benzothiazol-2-one with 4-hydroxy-4-methyl-2-pentynonitrile

Reaction between the title compounds gave the unexpected 3-[5,5-dimethyl-2,5-dihydrofur-4-yl-2-(3-isopropanol-2-propenonitrile)imino]benzothiazol-2-one, as a result of the addition of two cyanoacetylene molecules.Irkutsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Irkutsk 664033. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 4, pp. 1003–1005, April, 1992.     

Thioureas from 3-aminoquinazolin-4(3H)-one. 2. Unusual alkaline recyclization of 3-(N",N",S-trialkylisothioureido)quinazolin-4(3H)-ones into new 1,3,4-oxadiazoles

3-(N",N",S-trialkylisothioureido)quinazolin-4(3H)-ones obtained by the reactions of 3-(N",N"-dialkylthioureido)quinazolin-4(3H)-ones with alkyl halides undergo unusual recyclization into 5-(2-aminophenyl)-2-dialkylamino-1,3,4-oxadiazoles under the action of aqueous solutions of alkali, hydrazine, and primary aliphatic amines. A plausible mechanism of the recyclization was proposed.     

2-Polyfluoroalkylchromones. 9. Synthesis and structures of 5-(2-hydroxyaryl)-7-polyfluoroalkyl-1,4,8-triazabicyclo[5.3.0]dec-4-enes

2-Polyfluoroalkylchromones reacted with diethylenetriamine at 20 °C to form the corresponding 1,4,8-triazabicyclo[5.3.0]dec-4-ene derivatives. The crystal structures of 5-(2-hydroxyphenyl)-7-trifluoromethyl-1,4,8-triazabicyclo[5.3.0]dec-4-ene and 1-(2-aminoethyl)-7-(2-hydroxy-5-methoxyphenyl)-5-(1,1,2,2-tetrafluoroethyl)-2,3-dihydro-1H-1,4-diazepine were established by X-ray diffraction analysis.     

Base-assisted intramolecular 6-acetoxypyranone-acetylene [5+2] cycloaddition. Synthesis and reactivity of novel oxa-tricyclo[5.3.1.0]undecenones

The synthesis of 3,11-dioxatricyclo[5.3.1.0^1,5]undeca-5,9-dien-8-ones is reported from suitable 5-substituted furfuryl alcohols bearing an acetylenic side-chain. Successive peracid-mediated oxidative rearrangement of furan carbinols and base-assisted intramolecular 1,3-dipolar cycloaddition afforded oxygen-bridged tricyclo-undecane derivatives. Stereoselective transformations of cycloadducts are also discussed.     

Efficient and fast Heck vinylation of 2-bromo-6-methyl pyridines with methylacrylate. Application to the synthesis of 6-methyl cyclopenta[b]pyridinone

Heck vinylation of 2-bromo-6-methyl-3-substituted pyridines using η³-allylpalladium chloride dimer/P(o-Tol)₃ complex/toluene and dimethylacetamide (DMA) as co-solvent with methyl acrylate is reported. Electronic and steric effects were investigated engaging diversely 2-bromo-3,6-disubstituted pyridines. As application, a new synthesis of the 6-methyl cyclopenta[b]pyridinone building-block connecting Heck vinylation, alkene reduction and Dieckmann condensation is described.     

Thermal cyclization of N-[2-(2-propenyl)-1-naphthyl] ketenimines: intramolecular Diels-Alder reaction versus [1,5] hydrogen migration. Synthesis of dibenz[b,h]acridines and benzo[h]quinolines

The thermal treatment of N-(2-propenyl)-1-naphthylamines provided the expected aza-Claisen rearranged products, 2-(2-propenyl)-1-naphthylamines and benz[g]indoles, these last derived from an intramolecular hydroamination reaction on those primary products. The 2-(2-propenyl)-1-naphthylamines were converted into their triphenylphosphazene derivatives, which by aza-Wittig reaction with disubstituted ketenes yielded N-[2-(2-propenyl)-1-naphthyl] ketenimines. The heating of these ketenimines in boiling toluene induced their cyclization either via an intramolecular Diels-Alder reaction, to afford dibenz[b,h]acridines, or via [1,5] hydrogen migration from the sp³ carbon atom of the propenyl substituent to the central carbon atom of the ketenimine fragment, followed by a 6π electrocyclic ring closure, to give benzo[h]quinolines.