Chlorovinylidenecarbene: generation from 3,3-dichloropropyne by interaction with potassium hydroxide under phase-transfer catalysis conditions and reactions with alkenes

Chlorination of propargyl aldehyde with PCl₅ in CH₂Cl₂ at –20 °C in the presence of catalytic amounts of pyridine afforded dichloromethylacetylene. Reaction of the latter with powdered KOH under phase-transfer catalysis conditions gave chlorovinylidenecarbene due to -elimination of HCl. In the presence of alkenes the carbene undergoes addition at the double bond giving chlorovinylidenecyclopropanes in 20–45 % yields.For the previous communication, see Ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1242–1244, July, 1993.     

Preparation and structure of 3-chloro-7, 8 of 3-chloro-7,8-dimethylbenzo[e]-2,4,3-dithiastibepine

Conclusions The reaction of 1,2-dimethyl-4,5-di(mercaptomethyl)benzene with SbCl₃ gave 3-chloro-7,8-dimethylbenzo-[e]-2,4,3-dithiastibepine.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2814–2815, December, 1982.     

Alkynylhalocarbenes. 4. Generation of (alk-1-ynyl)halocarbenes from 3-substituted 1,1,1,3-tetrahalopropanes under the action of bases

When treated with KOH under phase-transfer catalysis or with Bu^tOK, 3-substituted (alkyl or phenyl) 1,1,3-tribromo-1-fluoropropanes 1a—c exclusively generate previously unknown (alk-1-ynyl)fluorocarbenes 5a—c, which react with olefins to give 1-(alk-1-ynyl)-1-fluorocyclopropanes 6a—h in 12—69% yields. Under analogous conditions, 3-alkyl- and 3-aryl-3-bromo-1,1,1-trichloropropanes 2a—c selectively afford (alk-1-ynyl)chlorocarbenes 7a—c, which are trapped by olefins to form the corresponding 1-(alk-1-ynyl)-1-chlorocyclopropanes 8a—k in 35—70% yields. (Phenylethynyl)chlorocarbene 7a is also selectively generated from 1,1,1,3-tetrachloro-3-phenylpropane (3a) upon its treatment with Bu^tOK. With an excess of 2,3-dimethylbut-2-ene or 2-methylpropene, carbene 7a yields 1-chloro-1-(phenylethynyl)cyclopropanes 8a or 8c, respectively. In contrast, 1,1,1,3-tetrachloroheptane 3b and 3-alkyl- and 3-phenyl-1,1,1,3-tetrabromopropanes 4a,c,f react with bases in the presence of olefins to give, along with the corresponding 1-(alk-1-ynyl)-1-halocyclopropanes 8a,c,d and 11a—f, vinylidenecyclopropanes 12a,c—g, which suggests the generation, under these conditions, both (alk-1-ynyl)halocarbenes 7b and 9a—c and vinylidenecarbenes 10 and 11a—c. The composition and structures of intermediate products in the reactions of tetrahalides 1b, 2a, 2b, 3a, and 3b with Bu^tOK were determined and the mechanisms for carbene generation in these reactions were proposed.     

Phase-transfer catalyzed alkoxylation of 2-(dichloromethyl) furan by alcohols in the presence of potassium hydroxide

Reaction of 2-(dichloromethyl)furan (I) with KOH in a CH₂Cl₂ medium and in the presence of alcohols (methanol, ethanol, and n-butanol) and a catalytic amount of triethylbenzylammonium chloride (TEBAC) results in the formation of 2-chloro-methylene-5-alkoxy-2, 5-dihydrofurans (II) (mixtures of Z- and E-isomers) and 2-dialkoxymethylfurans (III), in overall yields of up to 96%. Reaction with isopropyl and tert-butyl alcohols gave only the corresponding products (II), in 21 and 12% yield, respectively.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1403–1407, June, 1991.     

Reactions of organyltrifluoro- and diorganyldifluoro- silanes with 1,1,3,3-tetramethyldisiloxane

1,1,3,3-Tetramethyldisiloxane is decomposed by organyltrifluoro- and diorganyl- difluorosilanes already at 20C in the presence of catalysts with formation of hitherto unknown 1,1-dimethyl-3,3-diorganyl-3-fluoro- and 1,1-dimethyl-3-organyl-3,3-difluorodisiloxanes of general formula R_4–nSiF_n–1OSiH(CH₃)₂ (n=2–3) in yields of 50–70%. On storing these decomposition products easily disproportionate in various directions, in which their propensity to disproportionation is determined by the nature of the substituents at the silicon atoms and the number of fluorine atoms in the molecule.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1162–1166, May, 1991.     

Synthesis and reactions of 1-(4-chloro-, 3-chloro-, 2-chloro-, 2,4-dichloro-, and 2,4-difluorophenyl)-6,6-dimethyl-4-oxo-4,5,6,7-tetrahydroindazoles

Reaction of the potassium salt of 2-formyldimedone with hydrochlorides of 4-chloro-, 3-chloro-, 2-chloro-, 2,4-dichloro-, and 2,4-difluorophenylhydrazines gave the corresponding 2-arylhydrazinomethylene-dimedones which cyclized in acid media to 1-substituted 6,6-dimethyl-4-oxo-4,5,6,7-tetrahydroindazoles. Oxidation of the latter with selenious acid gave the corresponding 4,5-dioxo-4,5,6,7-tetrahydroindazoles which were further converted into 3-aryl-5,5-dimethyl-4,5-dihydro-3H-pyrazolo[4,3-a]phenazines and 2,6-diaryl-4,4-dimethyl-4,5-dihydro-1H(3H)-indazolo[4,5-g]imidazoles.Riga Technical University, Riga LV-1658, Latvia; e-mail: marina@osi.lv. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, 533–539, April, 2000.     

Enantioselective syntheses of no-carrier-added (n.c.a.) (s)-4-chloro-2-[f] fluorophenylalanine and (s)-(α-methyl) -4-chloro-2-[f]fluorophenylalanine

(S)-4-Chloro-2-fluorophenylalanine and (S)-(α-methy)-4-chloro-2-fluorophenylalanine were synthesized and labeled with no carrier added (n.c.a.) fluorine-18 through a radiochemical synthesis relying on the highly enantioselective reaction between 4-chloro-2-[¹⁸F]fluorobenzyl iodide and the lithium enolate of (2S)-1-(tert-butyloxycarbonyl)-2-(tert-butyl)-3-methyl-1,3-imidazolidine-4-one for (S)-4-chloro-2-[¹⁸F]fluorophenylalanine and (2S,5S)-1-(tert-butyloxycarbonyl)-2-(tert-butyl)-3,5-dimethyl-1,3-imidazolidine-4-one for (S)-(α-methyl) -4-chloro-2-[¹⁸F] fluorophenylalanine. Quantities of about 20–25 mCi were obtained at the end of sy nthesi s, ready for injection after hydrolysis and high performance liquid chromatography (HPLC) purification, with a radiochemical yield of 17%–20% corrected to the end of bombardment after a total synthesis time of 90–105 min from [¹⁸F] fluoride. The enantiomeric excesses were shown to be 97% or more for both molecules without chiral separation and the radiochemical and chemical purities were 98% or better.     

Reaction of diazoalkanes with unsaturated compounds. Report 4. Cyclopropanation of vinyl- and allylhalides with diazomethane in the presence of copper (I) chloride and triphenylphosphite

Conclusions Reaction of vinylhalides (vinylbromide, 1-chloro-1-cyclopropylethylenes) with CH₂N₂ in the presence of (PhO)₃P·CuCl leads to formation of the corresponding halocyclopropanes with 13–15% yields, while reaction of CH₈N₂ with alkylbromide under the same conditions gives the product of formal methylene introduction, 4-bromobut-1-ene (yield 58%) with insignificant formation (1%) of bromomethylcyclopropane.For Report 3 see [1].Translated from Izvestiya Akademii Nauk SSSR, Vol. 23, No. 1, pp. 135–138, January, 1987.     

Halogenation of Imidazo[4,5-<Emphasis Type="Italic">b</Emphasis>]pyridin-2-one Derivatives

Chlorination and bromination of 2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-one and its N-methyl-substituted derivatives in acetic acid at 90–95°C leads to formation of the corresponding 5,6-dichloro(dibromo)-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-ones. Iodination of the same substrates with ICl under analogous conditions yields 6-iodo derivatives. Chlorination of 6-iodo-1,3-dimethyl-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-one is accompanied by replacement of the iodine atom by chlorine with formation of 5,6-dichloro-1,3-dimethyl-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-one. Bromination of 6-bromo- and 6-chloro-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-ones gives 5,6-dibromo- and 5-bromo-6-chloro-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-ones, respectively.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 4, 2005, pp. 586–589.Original Russian Text Copyright © 2005 by Yutilov, Lopatinskaya, Smolyar, Gres’ko.     

Cyclodextrin Complexation of the Stilbene 4-(2-(4-Tert-butylphenyl)ethen-1-yl)- benzoate and the Self-assembly of Molecular Devices

E-4-(2-(4- tert - butylphenyl) ethen-1- yl)benzoate, E-1^–, photoisomerizes to the Z-1^– isomer and vice versa in the free state and in the binary complexes 2·E-1^–, 2·Z-1^–, 3·E-1^– and 3·Z-1^– where 2 is the urea-linked cyclodextrin N-(6 ^A -deoxy--cyclodextrin-6 ^A - yl)-N-(6 ^A -deoxy--cyclodextrin-6 ^A - yl)urea and 3 is N,N- bis(6 ^A -deoxy--cyclodextrin-6 ^A - yl)urea. In 2·E-1^–and 3·E-1^– the stilbene occupies both cyclodextrin (CD) components of 2 and 3, whereas in 2·Z-1^– and 3·Z-1^– it only occupies one CD component while the other CD component is unoccupied. 4- tert - Butylphenolate, 4^–, and its carboxylate, 5^–, and sulfonate, 6^–, analogues form the ternary complex 2·Z-1^–·4^– and its analogues and also 3·Z-1^–·4^– and its analogues. These photoisomerize to 2·E-1^–and 3·E-1^– and either free 4^–, 57^– or 6^– and thereby function as molecular devices.     

Rhodium-benzimidazolidin-2-ylidene catalyzed addition of arylboronic acids to aldehydes

Six rhodium–carbene complexes (2a–f) have been prepared and the new compounds characterized by C, H, N analyses, ¹H-n.m.r. and ¹³C-n.m.r. Phenylboronic acid reacts with aldehydes in the presence of a catalytic amount of rhodium(I)–carbene complex, RhCl(COD)(1,3-dialkylbenzimidazolidin-2-ylidene), (2a–f), to give the corresponding aryl secondary alcohols in good yields.     

Alkynylhalocarbenes. 2. Generation of (alkyn-1-yl)-chlorocarbenes by basic solvolysis of 1,1-dichloro-2-alkynes and their reaction with olefins: Synthesis of 1-chloro-1-alkynylcyclopropanes

1,1-Dichloro-2-alkynes R¹CCCHCl₂ (4a–g; R¹=Me, n-Pr, c-Pr, t-Bu, Ad, Nor, Ph) were synthesized with yields of 50–75% by chlorination with PCl₅ of formylacetylenes (3a–g), prepared by oxidation of propargyl alcohols (1a–d) with CrO₃·Py·HCl complex or acidolysis of propargyl acetals (2a–c) in the presence of catalytic quantities of pyridine; the corresponding alkynylchlorocarbenes, R¹CCCCl (5a–g) were generated from them with powdered KOH in a two-phase system or t-BuOK. The latter were trapped by olefins with formation of 1-chloro-1-alkynylcyclopropanes (6a–t) with yields of up to 90%.See [1] for Communication 1.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 5, pp. 1128–1135, May, 1992.     

Synthesis and properties of 5-chloro-4-nitropyrazoles

The nitration of 5-chloropyrazoles with a mixture of 100% nitric acid and 65% oleum or a mixture of 60% nitric acid and polyphosphoric acid gave substituted 5-chloro-4-nitropyrazoles in 45–91% yield. The nitration of 3-aryl-5-halopyrazoles was accompanied by introduction of a nitro group into the aromatic ring. 4-Chloropyrazoles failed to undergo nitration under these conditions. The reaction of 5-chloro-1,3-dimethyl-4-nitropyrazole with ethyl cyanoacetate in DMSO in the presence of K₂CO₃ led to the formation of ethyl 2-cyano-2-(1,3-dimethyl-4-nitro-1H-pyrazol-5-yl)acetate.     

Synthesis of a symmetrical dithiirane

The reaction of p-xylene with epichlorohydrin in the presence of aluminum chloride gave 1,4-dimethyl-2,5-bis(1-chloro-2-hydroxypropyl)benzene, which serves as the starting compound for the synthesis of the corresponding symmetrical dithiirane.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1319–1321, October, 1985.     

Synthesis of pyridine and picolines over modified silica-alumina and ZSM-5 catalysts

In the reaction of acetaldehyde, formaldehyde and ammononia over HZSM-5 (Si/Al-280), PbZSM-5 and WZSM-5 catalysts at 420°C, 0.5 h^–1 weight hourly space velocity, the total yields of pyridine and 3-picoline obtained were 58.2, 42.8 and 78.3 wt.% based on aldehydes, respectively. In the reaction of acetaldehyde and ammonia over typical Pb–SiO₂–Al₂O₃ (20% PbO), W–SiO₂–Al₂O₃ (10% W), Pb–Cr–SiO₂–Al₂O₃ (F) and Pb–Cu–SiO₂–Al₂O₃ (E) catalysts at 420°C, 0.5 h^–1 W.H.S.V., the yields of 2- and 4-picolines obtained were 51.1, 66.1, 80.6 and 53.7 wt.%, respectively.IICT Communication No. 3421, — dedicated to Dr. A.V. Rama Rao on his 60th birthday.     

Self quenching reaction of (Phenoxymethyl)chlorocarbene with diazirine

The combination of laser flash photolysis and product analysis demonstrates that even though (phenoxymethyl)chlorocarbene reacts with its diazirine precursor with a substantial rate constant of 3.5 x 10⁸ M^-1S^-1, the predicted azine product is not formed. These results indicate either carbene/diazirine reversibility or subsequent hydrogen migration of the carbene/diazirine adduct. Also, a rate constant of 2.0 x 10⁷ S^-1 for the 1,2-hydrogen atom migration in (p-nitrophenoxymethyl)chlorocarbene has been determined using the pyridinium ylide technique.     

Bis(2-t-butylphenyl)phosphonoacetamides for the highly cis-selective synthesis of α,β-unsaturated amides

New Horner–Wadsworth–Emmons reagents, (o-t-BuPhO)₂P(O)CH₂CONMe(OMe) and (o-t-BuPhO)₂P(O)CH₂CON(CH₂CH₂) ₂O were prepared via the Arbuzov reaction in good yields. The HWE reaction of these reagents with a variety of aldehydes gave cis-α,β-unsaturated amides with high selectivity in almost quantitative yields.     

Nucleophilic substitution in the 10,11-dihydrodibenz[b,f]iodepinium cation

10,11-Dihydrodibenz[b,f]iodepinium tetrafluoroborate gave only 1-(2-azidophenyl)-2-(2-iodophenylethane with the N₃ ^– in aqueous DMSO, while with NO₂ ^– it gave 1-(2-nitrophenyl)-2-(2-iodophenyl)ethane (93%), 9,10-dihydrophenanthrene (5%), and traces of phenanthrene. Both in pure and aqueous DMSO this cation with the Br^– ion was converted into phenanthrene (80% and 68% respectively) and 1-(2-bromophenyl)-2-(2-iodophenyl)ethane (10 and 20%), while in water it gave 9,10-dihydrophenanthrene (75%) and phenanthrene (5%). A new route for the synthesis of 1-(2-aminophenyl)-2-phenylethane starting from this tetrafluoroborate has been proposed.M. V. Lomonosov Moscow State University, Moscow 119899, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, 110–115, January, 1999.     

Investigation of heterocycles containing nitrogen or sulfur. 48. Derivatives of 1-morpholinooxalyl-1,2-dihydrothiazolo-[5,4-b]pyridine,their structure,and reactions

The structures of the products of reactions of 1-N-morpholinooxahi-1,2-dihydrothiazolo-[5,4-b]pyridine have been studied by IR, NMR, UV, and mass spectroscopy. Geometric (cis-anti) and rotational (about the CO-N amide bond) isomers of 1-N-morpholinooxalyl-2-propionyi-5-chloro-1,2-dihydrothiazolo-[5,4-b]pyridine oxime have been observed and studied. Treatment of 1-N-morpholinooxalyl-2-propionyl-5-chloro-1,2-dihydrothiazolo[5,4-b]pyridine with ethanolic alkali gave 2-propionyl-5-chlorothiazolo-[5,4-b]pyridine, while treatment with concentrated H₂SO₄ gave 1,2-dioxo-ethylidene-7-chloroxazolidino[3,2-f]pyrido[2,3-b]1,4-thiazine.For Communication 47 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1133–1138, August, 1993.     

Reactions of Substituted 2,3,7-Triazabicyclo[3.3.0]oct-2-enes and 1,2,7-Triazaspiro[4.4]non-1-enes with Halogens

Halogenation of 1-substituted 7-aryl-2,3,7-triazabicyclo[3.3.0]oct-2-ene-6,8-diones gives different products, depending on the substituent in position 1 (R¹): when R¹ = Ar, 6-chloro-3-azabicyclo[3.1.0]hexanes are formed, while compounds with R¹ = H or Me give rise to 2- or 4-chloro-2,3,7-triazabicyclo[3.3.0]oct-2-ene-6,8-diones whose thermolysis leads to formation of the corresponding 6-chloro-3-azabicyclo[3.1.0]hexanes. Chlorination of 7-aryl-1,2,7-triazaspiro[4.4]non-1-ene-6,8-diones yields 3-chloro-1,2,7-triazaspiro[4.4]non-1-ene-6,8-diones, and thermolysis of the latter affords 1-chloro-5-azaspiro[2.4]heptanes.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 1, 2005, pp. 78–88.Original Russian Text Copyright © 2005 by Molchanov, Stepakov, Kostikov.