Time filter

Source Type

Bremen, Germany

Iaroshenko V.O.,University of Rostock | Iaroshenko V.O.,Taras Shevchenko National University | Bunescu A.,University of Rostock | Bunescu A.,Leibniz Institute for Catalysis at the University of Rostock | And 7 more authors.
Journal of Fluorine Chemistry | Year: 2011

A formal [3+3] cyclocondensation of 1,3-bis(silyl enol ethers) with the little-known 4,4-dimethylthio-1,1,1-trifluorobut-3-en-2-one was studied. In contrast to 4,4-dimethoxy-1,1,1-trifluorobut-3-en-2-one, this α-oxoketene dithioacetal reacts with 1,3-bis(trimethylsilyloxy)-1,3-butadienes in the presence of TiCl4 to give mainly 6-methylthio-4-(trifluoromethyl) salicylates via 1,2-addition. The scope and limitations of the reaction are discussed. © 2011 Elsevier B.V. All rights reserved. Source

Sevenard D.V.,Hansa Fine Chemicals GmbH | Kazakova O.,University of Bremen | Schoth R.-M.,University of Bremen | Lork E.,University of Bremen | Roschenthaler G.-V.,University of Bremen
Journal of Chemical Crystallography | Year: 2011

The crystal structures of 2,5-bis(trifluoroacetyl) cyclohexane-1,4-dione (1) and o,o′-bis(trifluoroacetyl)-p-cresol (2) is reported. The first compound crystallizes in monoclinic space group P2 1/n with a = 6.5040(10), b = 10.1610(10), c = 8.2420(10) Å, β = 91.690(10)° and V = 0.54445(12) nm 3. Double enolization (U-structure) with a considerable electron density delocalization in the enolone backbone was established in this case. Phenol 2 crystallizes in triclinic space group P-1 with a = 7.0690(10), b = 9.4890(10), c = 9.8190(10) Å, α = 103.720(10), β = 110.760(10), γ = 102.150(10)° and V = 0.56598(12) nm 3. In contrast to CDCl 3 solution, a "bifurcate" structure of 2 with jumping OH proton is quenched: only one of both trifluoroacetyl moieties is bonded by intramolecular hydrogen bond. © Springer Science+Business Media, LLC 2011. Source

Filyakova V.I.,Russian Academy of Sciences | Boltacheva N.S.,Russian Academy of Sciences | Sevenard D.V.,Hansa Fine Chemicals GmbH | Charushina V.N.,Russian Academy of Sciences
Russian Chemical Bulletin | Year: 2010

1,5-Benzo[b]- and 1,5-naphtho[2,3-b]diazepines were synthesized by the reaction of lithium 1,3-diketonates with 1,2-diaminobenzene and 2,3-diaminonaphthalene in an MeOH-AcOH-HCl mixture at 0°C. The reactions of fluoroalkyl-containing lithium 1,3-diketonates with 1,2-diaminobenzene and 1,2-diamino-4,5-difluorobenzene under reflux in acetic acid afford 2-fluoroalkyl-containing benzimidazoles as the major products, whereas the reaction with 2-aminothiophenol gives 2-phenylbenzothiazole. The reactions of lithium diketonate containing the cyclohexane and cyclopentane moieties with 1,2-diaminoarenes and 2-aminobenzenethiol are accompanied by the opening of the carbocycle to form 2-(6-oxo-7,7,7-trifluoroheptyl)benzimidazole and 2-(5-oxo-6,6,6-trifluorohexyl)benzothiazole hydrates, respectively. © 2010 Springer Science+Business Media, Inc. Source

Sosnovskikh V.Y.,Ural Federal University | Sevenard D.V.,Hansa Fine Chemicals GmbH | Moshkin V.S.,Ural Federal University | El'Tsov O.S.,Ural Federal University
Russian Chemical Bulletin | Year: 2010

Reflux of 3-cyanothiochromone with benzylamine in toluene afforded 17-benzyl-6,7,14,15-tetrahydro-7,15-epiminobis(8H,16H-dithiochromeno)[2,3-b: 2′,3′-f][1,5]diazocine-6,14-dione, the self-condensation product of 2-amino-3-(benzyliminomethyl)thiochromone. Similar reaction with phenethylamine leads to 2-(thiochromon-3-yl)-5H-thiochromeno[2,3-d]-pyrimidin-5-one. Mechanism of formation of the dimeric products was considered. © 2010 Springer Science+Business Media, Inc. Source

Iaroshenko V.O.,University of Rostock | Iaroshenko V.O.,Taras Shevchenko National University | Mkrtchyan S.,University of Rostock | Mkrtchyan S.,Yerevan State University | And 10 more authors.
Tetrahedron | Year: 2012

3-Nitrochromone reacts with electron-rich aminoheterocycles (in glacial acetic acid at reflux) and anilines (in a mixture of DMF and TMSCl at 100-140 °C) to give a variety of hetero(carbo)annulated 3-nitropyridines. The reaction, involving a formal [3+3] cyclocondensation, proceeds in high yields and appears not to be influences greatly by the nature of the 1,3-C,N-dinucleophile as seen from the thorough scope study. The synthetic utility of the products was demonstrated by their conversion into the corresponding 3-aminopyridine derivatives. An NMR study and X-ray crystallographic analysis are reported. © 2012 Elsevier Ltd. All rights reserved. Source

Discover hidden collaborations