- Arylaliphatic 3-aza-1,5-diketones: Reactions with N-nucleophiles
-
1-Substituted 3,5-diphenylpyrazinium salts were obtained by reactions of tertiary bis(phenacyl)-amines with ammonium acetate, hydroxylamine hydrochloride, and hydrazine hydrate in acid medium. The reaction of quaternary dimethylbis(phenacyl)ammonium bromi
- Akimova,Trofimenko,Ivanenko
-
-
Read Online
- Non-interlayer and color stable WOLEDs with mixed host and incorporating a new orange phosphorescent iridium complex
-
In this work, we have synthesized a new phosphorescent iridium complex (Bppya)2Ir(acac), as an orange dopant for organic light-emitting diodes (OLEDs). The device achieved an external quantum efficiency (EQE) of 22.4%, a current efficiency of 49.5 cd A-1and a power efficiency of 38.9 lm W-1, which are among the highest values for orange OLEDs. Furthermore, color stable and high efficiency phosphorescent white OLED (WOLED) was demonstrated by utilizing a mixed-host in the emissive layers (EMLs) composed of a blue phosphor and the new orange phosphorescent emitter, as well as by avoiding the use of interlayers that commonly exist between different EMLs in WOLEDs. Our WOLED presented decent white emission with maximum efficiencies of 25.3 cd A-1and 12.6%. Furthermore, the 1931 Commission Internationale de l'Eclairage color coordinates exhibited extremely small variation of (0.3940 ± 0.0102, 0.4323 ± 0.0046) in a wide luminance range from 49 to 38,035 cd m-2when driving voltages increased from 4 V to 12 V. The root cause for this excellent color stability is the utilization of the mixed-host to obtain bipolar transport properties in EMLs as well as the eliminating of interlayer between different EMLs, which, on one hand, effectively broaden the exciton recombination zone; on the other hand, reduce the accumulation of triplet excitons at the emissive interface.
- Guo, Li-Yuan,Zhang, Xun-Lu,Zhuo, Min-Jie,Liu, Chen,Chen, Wang-Yang,Mi, Bao-Xiu,Song, Juan,Li, Yong-Hua,Gao, Zhi-Qiang
-
-
Read Online
- Triphenylene analogues with B2N2C2 cores: Synthesis, structure, redox behavior, and photophysical properties
-
A series of alkyl (1-3), aryl (6), and benzo-annulated (4,5) heteroaromatic triphenylene analogues with B2N2C2 cores have been synthesized via chelation of pyridazine derivatives using difunctional Lewis acidic diborabiphenyl precursors. In contrast to triphenylene, NICS(1) calculations on 1 suggested high aromaticities for the central (-11.3 ppm) and outer borabenzene rings (-7.7 ppm), along with nonaromatic behavior for the pyridazine ring (-0.7 ppm). Crystal structure analyses supported this analysis. When the a- and c-faces of the pyridazine moiety were free of substitution (1, 3), planar structures resulted, but upon substitution, a twisted B 2N2C2 core was observed due to steric repulsion of neighboring hydrogen atoms (e.g., 5). The increase of steric bulk from H (1) to ′Pr (3) in the planar species was found to result in a dimeric, head-to-tail herringbone packing motif, held together by close intermolecular B...N interactions of 3.39 A. One-electron reduction by Cp*2Co was found to afford the radical anions of 3 and 5, which were characterized by broad, featureless singlets in the EPR spectra; [3] .-[Cp*2Co]- was characterized by X-ray crystallography. While the planar structures (1-4) were observed to possess weak fluorescence (ΦF = 0.02-0.08) with either yellow-orange (ca. 555 nm) or green emission (521 nm), the twisted structures (5, 6) were found to be nonfluorescent.
- Jaska, Cory A.,Emslie, David J. H.,Bosdet, Michael J. D.,Piers, Warren E.,Sorensen, Ted S.,Parvez, Masood
-
-
Read Online
- Vinyl Azides as Radical Acceptors in the Vitamin B12-Catalyzed Synthesis of Unsymmetrical Ketones
-
Vinyl azides are very reactive species and as such are useful building blocks, in particular, in the synthesis of N-heterocycles. They can also serve as precursors of ketones. These form in reactions of vinyl azides with nucleophiles or radicals. We have found, however, that under light irradiation vitamin B12 catalyzes the reaction of vinyl azides with electrophiles to afford unsymmetrical carbonyl compounds in decent yields. Mechanistic studies revealed that alkyl radicals are key intermediates in this transformation.
- Dworakowski, Krzysztof R.,Pisarek, Sabina,Hassan, Sidra,Gryko, Dorota
-
supporting information
p. 9068 - 9072
(2021/11/30)
-
- One-Pot and Two-Chamber Methodologies for Using Acetylene Surrogates in the Synthesis of Pyridazines and Their D-Labeled Derivatives
-
Acetylene surrogates are efficient tools in modern organic chemistry with largely unexplored potential in the construction of heterocyclic cores. Two novel synthetic paths to 3,6-disubstituted pyridazines were proposed using readily available acetylene surrogates through flexible C2 unit installation procedures in a common reaction space mode (one-pot) and distributed reaction space mode (two-chamber): (1) an interaction of 1,2,4,5-tetrazine and its acceptor-functionalized derivatives with a CaC2?H2O mixture performed in a two-chamber reactor led to the corresponding pyridazines in quantitative yields; (2) [4+2] cycloaddition of 1,2,4,5-tetrazines to benzyl vinyl ether can be considered a universal synthetic path to a wide range of pyridazines. Replacing water with D2O and vinyl ether with its trideuterated analog in the developed procedures, a range of 4,5-dideuteropyridazines of 95–99% deuteration degree was synthesized for the first time. Quantum chemical modeling allowed to quantify the substituent effect in both synthetic pathways.
- Ananikov, Valentine P.,Ledovskaya, Maria S.,Polynski, Mikhail V.
-
p. 2286 - 2297
(2021/07/20)
-
- A green and practical one-pot two-step strategy for the synthesis of symmetric 3,6-diarylpyridazines
-
A simple, mild, and efficient synthesis of symmetric 3,6-diarylpyridazine derivatives using a green catalytic one-pot two-step reaction of aryl methyl ketones, arylglyoxal monohydrates, and hydrazine hydrate was developed. Environmentally benign nature, high atom-economy, no harmful byproduct, easy workup procedure, no column chromatography steps, and moderate to excellent yields of the products are the salient features of this new multicomponent-based methodology.
- Rimaz, Mehdi,Mousavi, Hossein,Khalili, Behzad,Aali, Farkhondeh
-
p. 1389 - 1397
(2018/11/26)
-
- Efficient Suzuki-Miyaura mono-arylation of symmetrical diiodo(hetero)arenes
-
A reliable protocol for converting 1,4-diiodo-2,3,5,6-tetrafluorobenzene into 1-(hetero)aryl-4-iodo-2,3,5,6-tetrafluorobenzene derivatives has been lacking in the literature. We have identified optimal conditions to achieve this conversion in good yields and have minimized formation of the bis-coupling product. The newly identified protocol involving the use of a syringe pump has been extended to other symmetrical diiodo(hetero)arenes.
- Sapegin, Alexander,Krasavin, Mikhail
-
supporting information
p. 1948 - 1951
(2018/04/16)
-
- B(C6F5)3-catalyzed metal-free hydrogenation of 3,6-diarylpyridazines
-
This paper describes the first metal-free hydrogenation of 3,6-diarylpyridazines, which was successfully realized using B(C6F5)3 as a catalyst. A variety of 1,4,5,6-tetrahydropyridazine derivatives were furnished in 85-95%
- Wang, Wei,Meng, Wei,Du, Haifeng
-
supporting information
p. 5945 - 5948
(2016/04/26)
-
- A general catalyst for Suzuki-Miyaura and Sonogashira reactions of aryl and heteroaryl chlorides in water
-
We report the synthesis of 2-(3-sulfonatomesityl)-5-sulfonatoindenyl) dicyclohexylphosphine hydrate sodium salt and its use in palladium-catalyzed Suzuki-Miyaura and Sonogashira coupling reactions in water (and biphasic water-organic solvent mixtures) to prepare a variety of functionalized biaryls and aryl alkynes in excellent yield. This journal is the Partner Organisations 2014.
- Peng, Hui,Chen, Ya-Qin,Mao, Shu-Lan,Pi, Yun-Xiao,Chen, You,Lian, Ze-Yu,Meng, Tong,Liu, Sheng-Hua,Yu, Guang-Ao
-
supporting information
p. 6944 - 6952
(2014/09/29)
-
- Non-interlayer and color stable WOLEDs with mixed host and incorporating a new orange phosphorescent iridium complex
-
In this work, we have synthesized a new phosphorescent iridium complex (Bppya)2Ir(acac), as an orange dopant for organic light-emitting diodes (OLEDs). The device achieved an external quantum efficiency (EQE) of 22.4%, a current efficiency of 49.5 cd A-1 and a power efficiency of 38.9 lmW-1, which are among the highest values for orange OLEDs. Furthermore, color stable and high efficiency phosphorescent white OLED (WOLED) was demonstrated by utilizing a mixed-host in the emissive layers (EMLs) composed of a blue phosphor and the new orange phosphorescent emitter, as well as by avoiding the use of interlayers that commonly exist between different EMLs in WOLEDs. Our WOLED presented decent white emission with maximum efficiencies of 25.3 cd A-1 and 12.6%. Furthermore, the 1931 Commission Internationale de l'Eclairage color coordinates exhibited extremely small variation of (0.3940 ± 0.0102, 0.4323 ± 0.0046) in a wide luminance range from 49 to 38,035 cd m-2 when driving voltages increased from 4 V to 12 V. The root cause for this excellent color stability is the utilization of the mixed-host to obtain bipolar transport properties in EMLs as well as the eliminating of interlayer between different EMLs, which, on one hand, effectively broaden the exciton recombination zone; on the other hand, reduce the accumulation of triplet excitons at the emissive interface.
- Guo, Li-Yuan,Zhang, Xun-Lu,Zhuo, Min-Jie,Liu, Chen,Chen, Wang-Yang,Mi, Bao-Xiu,Song, Juan,Li, Yong-Hua,Gao, Zhi-Qiang
-
p. 2964 - 2970
(2014/12/11)
-
- Highly stereo-selective synthesis of (Z)-2,3-diiodo-1,4-diarylbut-2-ene-1, 4-diones via oxidative iodination of 1,4-diarylbuta-1,3-diynes
-
A novel and highly stereo and regioselective oxidative iodination of 1,4-diarylbuta-1,3-diynes promoted by N-iodosuccinamide results in (Z)-2,3-diiodo-1,4-diarylbut-2-ene-1,4-diones. In the case of NBS, the stereo-selectivity is moderate while NIS gives exclusively Z product. A plausible mechanism for the formation of both E and Z products is also proposed.
- Singha, Raju,Dhara, Shubhendu,Ray, Jayanta K.
-
p. 23989 - 23992
(2013/11/19)
-
- Palladium-catalyzed cross-coupling reaction of functionalized aryl- and heteroarylbismuthanes with 2-halo(or 2-Triflyl)azines and -diazines
-
The palladium-catalyzed cross-coupling of highly functionalized organobismuthanes with 2-halo(or 2-triflyl)pyridines, -pyrimidines, -pyrazines, and -pyridazines is reported. The reaction tolerates numerous functional groups, including aldehydes. The synthesis of a shelf-stable (formylphenyl)bismuth reagent and its use in a cross-coupling reaction is also described. The palladium-catalyzed cross-coupling of highly functionalized organobismuthanes with 2-halo(or 2-triflyl)pyridines, -pyrimidines, -pyrazines, and -pyridazines is reported. The reaction tolerates numerous functional groups, including aldehydes. The synthesis of a shelf-stable (formylphenyl)bismuth reagent and its use in cross-coupling reactions is also described. Copyright
- Petiot, Pauline,Gagnon, Alexandre
-
supporting information
p. 5282 - 5289
(2013/09/02)
-
- Unexpected C-C bond cleavage: A route to 3,6-diarylpyridazines and 6-arylpyridazin-3-ones from 1,3-dicarbonyl compounds and methyl ketones
-
An unexpected C-C bond cleavage has been revealed in the absence of metal. This observation has been exploited to develop an efficient approach toward 3,6-diarylpyridazines and 6-arylpyridazin-3-ones from simple and commercially available 1,3-dicarbonyl compounds and methyl ketones.
- Gao, Qinghe,Zhu, Yanping,Lian, Mi,Liu, Meicai,Yuan, Jingjing,Wu, Anxin,Yin, Guodong
-
p. 9865 - 9870,6
(2012/12/12)
-
- Isonitriles as efficient ligands in Suzuki-Miyaura reaction
-
Isonitrile palladium complexes [(RNC)2PdCl2] were prepared and tested in Suzuki reaction of 4-chloroanisol. (AdNC)2PdCl2 was found the most effective catalyst and was used in phenylation of several chloro and bromoaromatic substrates.
- Villemin, Didier,Jullien, Arnaud,Bar, Nathalie
-
p. 4191 - 4193
(2008/02/05)
-
- Highly selective mono-substitution in Pd-catalyzed cross-coupling reactions of 3,6-dichloropyridazine with organozinc compounds
-
Pd-catalyzed cross-coupling reactions of 3,6-dichloropyridazine (1) with benzyl, aryl, and alkyl organozinc compounds led to selective mono-substitution of one of the chlorine atoms. The subsequent cross-coupling of the resulting monochlorides with RZnCl afforded unsymmetrical 3,6-carbon-disubstituted pyridazines.
- Chekmarev, Dmitriy S.,Stepanov, Alexander E.,Kasatkin, Alexander N.
-
p. 1303 - 1305
(2007/10/03)
-
- NOVEL USE OF TRICYCLIC COMPOUND
-
Pharmaceutical compositions for enhancing the expression of apoAI are provided, which are used as medicaments for treatment of cardiovascular diseases on the basis of improving the functions of HDL.Pharmaceutical compositions for enhancing the expression of apoAI which comprises a compound of formula (I): in which X1 and X2 are independently an aryl or heteroaryl that may be optionally substituted, a hydrogen, a halogen, or the like; ring A is a benzene ring or 6-membered aromatic heterocyclic ring containing 1 to 3 N atoms that may be optionally condensed with another aromatic ring; R1 to R4 are independently a hydrogen, a halogen, a lower alkyl, a lower alkoxy or the like; a prodrug thereof, a pharmaceutically acceptable salt or solvate of them are disclosed.
- -
-
Page/Page column 14-15; 17
(2008/06/13)
-
- Novel tandem reactions of 2,2′-sulfonylbis(1,3-diarylprop-2-en-1-ones) with hydrazine: Formation of 3,6-diarylpyridazines and 3,5-diarylpyrazoles
-
The 2,2′-sulfonylbis(1,3-diarylprop-2-en-1-ones) undergo tandem reactions with hydrazine affording 3,6-diarylpyridazines and 3,5-diarylpyrazoles unexpectedly, the latter predominating.
- Gnanadeepam,Selvaraj,Perumal,Renuga
-
p. 2227 - 2230
(2007/10/03)
-
- Solid phase synthesis of pyridazine derivatives using polymer-bound sodium benzenesulfinate
-
A new solid phase synthesis of 3,6-disubstituted pyridazine derivatives, resulting from the reaction of polymer-bound sodium benzenesulfinate with α-bromoketone substrates followed by condensation with hydrazine, is described. Mild basic conditions for the condensation reaction simultaneously release the desired product from the solid support. The crystal structure of 3,6-bis(p-chlorophenyl)pyridazine is reported.
- Chen, Yu,Lam, Yulin,Lee, Soo-Ying
-
p. 274 - 275
(2007/10/03)
-
- Degradational cyclization of α-[2-phenyl-2- (phenylsulfonylhydrazono)ethyl]phenacylidenetriphenylphosphoranes to 3,6- diphenylpyridazines and 5-benzoyl-3-phenylpyrazoles
-
α-[2-Phenyl-2- (phenylsulfonylhydrazono)ethyl]phenacylidenetriphenylphosphoranes were obtained (60-71%) by the reaction between phenylsulfonylhydrazones of phenacyl bromides and phenacylidenetriphenylphosphoranes. Thermolysis of the phosphoranes gave 3,6-diphenylpyridazines (43-66%) and 5-benzoyl-3- phenylpyrazoles (13-27%), together with triphenylphosphine oxide and S-phenyl benzenethiosulfonate, a disproportionation product from benzenesulfinic acid. The structure of the intermediate α-substituted phenacylidenetriphenylphosphorane was confirmed by an X-Ray diffraction method.
- Ito, Suketaka,Kakehi, Akikazu,Okada, Kyoko
-
p. 2949 - 2960
(2007/10/03)
-
- 1,2-Dithiines and precursors, XVI: Synthesis, structure, and reactivity of non-anellated 1,2-dithiines
-
Various monocyclic 1,2-dithiines 6a,b,d-t were prepared via (Z,Z)-1,4-difunctionalized butadienes (4-11,19,20). A twisted cyclic structure A is unequivocally proved rather than of the ringopened valence isomer B. The reactivity of these 1,2-dithiines is d
- Schroth, Werner,Dunger, Simona,Billig, Frank,Spitzner, Roland,Herzschuh, Rainer,Vogt, Almut,Jende, Thomas,Israel, Gunter,Barche, Jens,Stroehl, Dieter,Sieler, Joachim
-
p. 12677 - 12698
(2007/10/03)
-
- Microwave-assisted Diels-Alder reaction supported on graphite
-
The coupling of graphite (as a support) with microwaves (as an energy source), a new type of "dry reaction", was studied for some Diels-Alder reactions involving anthracene and azadienes. Graphite is responsible for a high-temperature gradient leading to increased reaction rates as compared to conventional procedures using a solvent. VCH Verlagsgesellschaft mbH, 1996.
- Garrigues, Bernard,Laporte, Christian,Laurent, Regis,Laporterie, Andre,Dubac, Jacques
-
p. 739 - 741
(2007/10/03)
-
- SYNTHESIS OF 4-AZAFLUORENES SUBSTITUTED AT THE POSITION 9 BASED ON 9,9-DIPHENACYL(PHENACYLIDENE)-4-AZAFLUORENE
-
Functionally substituted 4-azafluorenes were synthesized by the modification of the carbonyl groups of 9,9-diphenacyl-4-azafluorene.Tha usual reductive cleavage of 9,9-di(α-bromophenacyl)-4-azafluorene by hydrazine, leading to the formation of diphenylpyr
- Mustafa, Ammar,Mikhailova, N. M,Prostakov, N. S.
-
p. 1304 - 1307
(2007/10/02)
-
- SYNTHESIS OF 4-AZAFLUORENE DERIVATIVES BASED ON 9-(3,6-DIPHENYLPYRIDAZIN-4-YL)-4-AZAFLUORENE
-
The reaction of 9-(3,6-diphenylpyridazin-4-yl)-4-azafluorene with n-butyl acrylate under conditions of the Michael reaction affords the product of the condensation at the methine group.When sterically hindered esters of methacrylic, crotonic, and cynnamic
- Mustafa, Ammar,Mikhailova, N. M,Prostakov, N. S.
-
p. 1300 - 1303
(2007/10/02)
-
- Diazines VII. A new synthetic route to the pyridazine antidepressant, minaprine using directed ortho metalation and Suzuki cross coupling reactions
-
A new synthetic route has been developed for minaprine.The synthesis is based upon two reactions recently studied on pyridazine: metalation and cross coupling with transition metals.Some different routes have been tested starting from 3,6-dichloropyridazine.The best results were obtained by coupling phenylboronic acid with 3-chloro-6-methoxypyridazine then by metalating 3-methoxy-6-phenylpyridazine and reacting the lithio derivatives with methyl iodide. 3-Methoxy-4-methyl-6-phenylpyridazine was obtained.After hydrolysis of the ether moiety, chlorination and substitution by the amine, minaprine was obtained with an overall yield of 36percent.Keywords - pyridazine / metalation / cross-coupling
- Turck, A.,Ple, N.,Mojovic, L.,Queguiner, G.
-
p. 488 - 492
(2007/10/02)
-
- DIETHYLAMINE AND TRIETHYLAMINE AS SOURCES OF THE DIENOPHILE COMPONENT IN THE REVERSE AZADIENE SYNTHESIS WITH DIMETHYLPYRIMIDO- AND --1,2,4-TRIAZINEDIONES AND 1,2,4,5-TETRAZINES
-
Diethylamine (DEA) and triethylamine (TEA) can function as sources for the two-carbon component in the reverse azadiene synthesis.Reaction of 5,7-dimethylpyrimido-1,2,4-triazene-6,8-dione, 6,8-dimethylpyrimido--1,2,4-triazine-5,7-dione, or 1
- Shorshnev, S. V.,Esipov, S. E.,Kuz'menko, V. V.,Gulevskaya, A. V.,Pozharskii, A. F.,et al.
-
p. 1289 - 1301
(2007/10/02)
-
- Photochemical Generation of 1,4-Diphenylbutane-1,4-diyl
-
Photochemical deazetation of 3,6-diphenyl-3,4,5,6-tetrahydropyrazine (1) was re-examined; evidence was obtained for trapping of a diradical intermediate (2) by oxygen when (1) was photolysed in the absence of solvent.
- Kohmoto, Shigeo,Yamada, Kazuhito,Joshi, Umesh,Kawatuji, Teruyuki,Yamamoto, Makoto,Yamada, Kazutoshi
-
p. 127 - 129
(2007/10/02)
-
- Preparation of 3,6-Disubstituted Pyridazines from 3-Thiapentane-1,5-diones via 2,7-Dihydro-1,4,5-thiadiazepines
-
A series of 3-thiapentane-1,5-diones condense with hydrazine in the presence of a catalytic amount of p-toluenesulfonic acid in refluxing ethanol to give 2,7-dihydro-1,4,5-thiadiazepines in excellent yields.Thermal decomposition of the latter compounds in
- Nakayama, Juzo,Konishi, Toru,Ishii, Akihiko,Hoshino, Masamatsu
-
p. 2608 - 2612
(2007/10/02)
-
- PYRIDAZINE DERIVATIVES FROM ACYCLIC ENAMINES. CHAIN-RING TAUTOMERIC AND EPIMERIC EQUILIBRIUM IN 6-HYDROXY-1,4,5,6-TETRAHYDROPYRIDAZINES
-
The reaction between ω-bromoacetophenone semicarbazone and various morpholino-enamines of aldehydes and acyclic ketones have been studied.With the enamines of the aldehydes, the reaction leads to the exclusive formation of 6-amino-1,4,5,6-tetrahydropyrida
- Cocco, Maria Teresa,Congiu, Cenzo,Maccioni, Antonio,Plumitallo, Antonio
-
p. 187 - 192
(2007/10/02)
-
- A NOVEL SYNTHESIS OF PYRIDAZINES: INVERSE ELECTRON DEMAND DIELS-ALDER REACTION OF TETRAZINES WITH ACYCLIC DIENAMINES
-
Tetrazines (1) when reacted wuth dienamines (2) furnished, pyridazines (3) and (4) in good yields.This appears to be the first case wherein the intermediate bipyridazines (8) have fragmented to (3) and (4) prefering rupture of carbon-carbon bonds.
- Borthakur, Dipak Ranjan,Prajapati, Dipak,Sandhu, Jagir Singh
-
p. 337 - 340
(2007/10/02)
-
- Preparation of 5,5-Dicyano- and 5-Cyano-5-ethoxycarbonyl-5,5-dihydro-3,7-diphenyl-4H-1,2-diazepines and Their Halogenations
-
5,5-Dicyano- and 5-cyano-5-ethoxycarbonyl-5,6-dihydro-3,7-diphenyl-4H-1,2-diazepines were prepared by the condensation of α-bromoacetophenone azine with malonitrile and ethyl cyanoacetate in the presence of sodium ethoxide, respectively.Halogenations of t
- Kamata, Kichinosuke,Tsuge, Otohiko
-
p. 557 - 560
(2007/10/02)
-
- Bridgehead Hydrazines. 3. Unusual Photorearrangement of 1,4-Diphenylpyridazinophthalazine-6,11-dione
-
1,4-Diphenylpyridazinophthalazine-6,11-dione (2a) was prepared through Diels-Alder reaction of phthalazine and 1,4-diphenylbutadiene, followed by allylic bromination and thermal 1,4-dehydrobromination.Upon photolysis, 2a isomerized to an isoindolo
- Sheradsky, Tuvia,Moshenberg, Reuven
-
p. 3123 - 3125
(2007/10/02)
-
- THERMAL HETEROCYCLIZATION OF METHYL ARYL KETAZINES. I. REACTIONS OF THE TAUTOMERIC DIENEHYDRAZINE FORM
-
The thermal reactions of methyl aryl ketazines in the range of 150-350 deg C were studied.Thermolysis is represented by three types of parallel-consecutive reactions of various tautomeric forms of the initial compounds, i.e., the dienehydrazine, the enehydrazine, and azine forms.The chemical transformations of the first type lead to the cyclization of the azines into derivatives of 2,5-diarylpyrrole and 3,6-diarylpyridazine.The formation of pyrroles under the conditions of uncatalyzed thermolysis and at temperatures excluding the possibility of processes involvingthe participation of radicals is consistent with the mechanism of a -sigmatropic shift.
- Shurukhin, Yu. V.,Klyuev, N. A.,Grandberg, I. I.
-
p. 1883 - 1888
(2007/10/02)
-
- A CONVENIENT SYNTHESIS OF 3,6-DIARYLPYRIDAZINES
-
Cathodic reductions of phenacylbromides semicarbazones lead to 1,4-diaryl-1,4-butanedione disemicarbazones which give the corresponding 3,6-diarylpyridazines directly by heating.
- Barba, F.,Velasco, M. D.,Guirado, A.,Moreno, N.
-
p. 939 - 944
(2007/10/02)
-
- A SIMPLE METHOD FOR THE SYNTHESIS OF SOME 1,2-DIAZOCINES
-
Cyclobutanone reacts with diphenyl-1,2,4,5-tetrazine, in alcoholic base and in diethylamine, to give 3,8-diphenyl-6,7-dihydro-1,2-diazocin-4(5H)-one (5) and 4-diethylamino-3,8-diphenyl-6,7-dihydro-1,2-diazocine (8) respectively.With diethylamine the tetra
- Haddadin, Makhluf J.,Agha, Bushra J.,Salka, M. Samer
-
p. 2577 - 2580
(2007/10/02)
-
- The Role of Lithium Amides as Reducing Agents in a Novel Pathway to 3,6-Diarylpyridazines by Ring Transformations of 3,6-Diaryl-s-tetrazines
-
3,6-Diaryl-s-tetrazines undergo two competing reactions when treated with lithium amides.The first, direct nucleophilic attack and addition of lithium amide to the tetrazine, appears to be predominant when a less hindered amide is used, and moderate quantities of tetrazine are then regenerated on quenching.The competing reaction, which is seen more clearly with a bulkier amide such as lithium di-isopropylamide, involves reduction of tetrazine to a dihydro derivative with concomitant formation of imine from the amide: this imine is then attacked by further amide and gives rise to a charged intermediate which reacts with more tetrazine to form a pyridazine.
- Hunter, Daniel,Neilson, Douglas G.
-
p. 1601 - 1603
(2007/10/02)
-
- Facile Syntheses of 1,4,5-Thiadiazepine, 1,4,7-Thiadiazonine, Imidazothiazine and Pyrimidothiazine
-
The condensation of diphenacyl sulphides with hydrazine hydrate, 1,2-diaminoethane, 1,2-diaminopropane and 1,3-diaminopropane, performed in ethylene glycol-ethanol (3: 2) medium provides convenient syntheses of 3,6-diaryl-2,7-dihydro-1,4,5-thiadiazepine (
- Sandhu, S. S.,Tandon, S. S.,Singh, Harjit
-
p. 1023 - 1027
(2007/10/02)
-
- An unusual example of a 1,1-cycloaddition reaction of a diazoalkane
-
Thermolysis of the sodium salt of E-1,4-diphenyl-3-buten-1-one N-tosylhydrazone gave rise to the corresponding diazoalkane which undergoes a subsequent 1,1-cycloaddition reaction to produce 3,6-diphenyl-1,2-diazabicyclo[3.1.0]hex-2-ene.
- Padwa, Albert,Ku, Hao
-
p. 1009 - 1012
(2007/10/02)
-