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1.
Ahmad Shaabani Fatemeh Hajishaabanha Hamid Mofakham Mojtaba Mahyari Bagher Lali 《Helvetica chimica acta》2012,95(2):246-254
A novel and efficient isocyanide‐based multicomponent reaction between alkyl or aryl isocyanides 1 , 2,3‐diaminomaleonitrile ( 2 ), naphthalene‐2,3‐diamines ( 6 ) or benzene‐1,2‐diamine ( 9 ), and 3‐oxopentanedioic acid ( 3 ) or Meldrum's acid ( 4 ) or ketones 7 was developed for the ecologic synthesis, at room temperature under mild conditions, of 1,6‐dihydropyrazine‐2,3‐dicarbonitriles 5a – 5f in H2O without using any catalyst, and of 3,4‐dihydrobenzo[g]quinoxalin‐2‐amine and 3,4‐dihydro‐3,3‐dimethyl‐quinoxalin‐2‐amine derivatives 8a – 8g and 10a – 10e , respectively, in the presence of a catalytic amount of p‐toluenesulfonic acid (TsOH) in EtOH, in good to excellent yields (Scheme 1). 相似文献
2.
Synthesis of 4‐Aryl‐8‐fluoro‐3a,4,5,9b‐tetrahydro‐3H‐cyclopenta[c]quinolines and Their Ozonides
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Alexander G. Tolstikov Rimma G. Savchenko Elena S. Lukina Denis V. Nedopekin Regina M. Limantceva Leonard M. Khalilov Ekaterina S. Mescheryakova Victor N. Odinokov 《Helvetica chimica acta》2014,97(10):1317-1325
4‐Aryl‐8‐fluoro‐3a,4,5,9b‐tetrahydro‐3H‐cyclopenta[c]quinolines are synthesized by acid‐catalyzed (CF3CO2H) three‐component cyclocondensation of 4‐fluoroaniline with aromatic aldehydes and cyclopentadiene. Stable ozonides with (1R*,4S*,5aR*,6S*,11bS*)‐configurations are obtained by ozonolysis of corresponding trifluoroacetyl derivatives. 相似文献
3.
Biswanath Das Penagaluri Balasubramanyam Gandolla Chinna Reddy Nayaki Salvanna 《Helvetica chimica acta》2011,94(7):1347-1350
Several (2‐amino‐4H‐1‐benzopyran‐4‐yl)phosphonates were efficiently synthesized by employing a multicomponent protocol involving a salicylaldehyde, malononitrile or ethyl cyanoacetate, and a trialkyl phosphite in polyethylene glycol. The latter could be recovered and re‐used. No additional solvent or catalyst was required. To the best of our knowledge, this is the first report of the one‐pot preparation of (2‐amino‐4H‐1‐benzopyran‐4‐yl)phosphonic acid dimethyl esters. 相似文献
4.
4‐Arylisocoumarins (=4‐aryl‐1H‐2‐benzopyran‐1‐ones) 6 were prepared from 2‐(1‐aryl‐2‐methoxyethenyl)‐1‐bromobenzenes 1 . Successive treatment of these bromo styrenes with BuLi and 1‐formylpiperidine gave a mixture of (E)‐ and (Z)‐2‐(1‐aryl‐2‐methoxyethenyl)benzaldehydes 2 . Hydrolysis of (Z)‐isomers with conc. HBr, followed by pyridinium chlorochromate (PCC) oxidation of the resulting 1H‐2‐benzopyran‐1‐ol derivatives 4 (and 5 ), afforded the desired products. 相似文献
5.
An efficient approach for the preparation of functionalized 2‐aryl‐2,5‐dihydro‐5‐oxo‐4‐[2‐(phenylmethylidene)hydrazino]‐1H‐pyrroles is described. The four‐component reaction between aldehydes, NH2NH2?H2O, dialkyl acetylenedicarboxylates, and 1‐aryl‐N,N′‐bis(arylmethylidene)methanediamines proceeds in EtOH under reflux in good‐to‐excellent yields (Scheme 1). The structures of 4 were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS, and, in the case of 4f , by X‐ray crystallography). A plausible mechanism for this type of reaction is proposed (Scheme 2). 相似文献
6.
The title compound was prepared by reaction of N, N‐dimethyldithiocarbamate sodium with l‐bromo‐l‐(4‐methoxyphenylcarbonyl)‐2‐(1, 2, 4‐triazole‐l‐yl) ethane. Its crystal structure has been determined by X‐ray diffraction analysis. The crystal belongs to triclinic with space group Pī, a = 0.7339(2) nm, b = 1.1032(2) nm, c = 1.1203(2) nm, a = 90.27(3)°, β = 102.03(3)°, γ = 104.91(3)°, Z=2, V = 0.8556(3) nm3, Dc = 1.360 g/cm3, μ =0.325 mm?1, F(000)=368, final R1 =0.0475. The planes of 4‐methoxybenzyl group and triazole ring are nearly perpendicular to each other. The dihedral angle is 83.97°. There is an obvious π‐π stacking interaction between the molecules in the crystal lattice. The results of biological test show that the title compound has fungicidal and plant growth regulating activities. 相似文献
7.
The reaction of dialkyl acetylenedicarboxylates with arylidenemalononitriles in the presence of KSCN in MeCN led to a mixture of dialkyl (3E)‐4‐aryl‐3‐(arylideneamino)‐5,5‐dicyanocyclopenta‐1,3‐diene‐1,2‐dicarboxylates and dialkyl 4‐aryl‐5‐cyanothiophene‐2,3‐dicarboxylates. When these reactions were performed in the presence of KCN, only the functionalized 5,5‐dicyanocyclopenta‐1,3‐dienes were obtained. 相似文献
8.
Abdolali Alizadeh Zohreh Noaparast Hamideh Sabahno Nasrin Zohreh 《Helvetica chimica acta》2010,93(7):1401-1406
Synthesis and characterization of bis[2‐(arylimino)‐1,3‐thiazolidin‐4‐ones] are described. The one‐pot, pseudo‐five‐component reaction of an aliphatic diamine, isothiocyanatobenzene, and dialkyl but‐2‐ynedioate at room temperature in anhydrous CH2Cl2 gives the title compound in relatively high yield. Under the same conditions, aromatic 1,2‐diamines yield 2‐(arylimino)‐N‐(enaminoaryl)‐1,3‐thiazolidin‐4‐ones in a pseudo‐four‐component reaction. Their structures were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this type of cyclization is proposed (Scheme 3). 相似文献
9.
Three 3‐amino‐1, 2, 4‐triazole (atz)‐based paramagnetic complexes, [Mn(atz)(pa)]n ( 1 ), {[Mn(atz)1.5(hip)] · H2O}n ( 2 ), and [Mn(H2O)2(atz)2(nb)2] ( 3 ) (H2pa = o‐phthalic acid, H2hip = 5‐hydroxylisophthalic acid, and Hnb = p‐nitrobenzoic acid) were prepared by introducing different carboxylate‐containing aromatic coligands, and structurally and magnetically characterized. Helical MnII‐atz and bent MnII‐pa2– chains are crosslinked by sharing the same metal sites to generate a honeycomb‐shaped framework of 1 . The undulated MnII‐atz layers constructed from 22‐member metallomacrocycles are periodically supported by ditopic hip2– ligands to lead to a pillared‐layer structure of 2 . In contrast, complex 3 is a centrosymmetric mononuclear entity, which is assembled into a three‐dimensional supramolecular network by abundant hydrogen‐bonding interactions. The structural difference of 1 – 3 is significantly due to the combinations of the flexible coordination modes adopted by the mixed atz and carboxylate groups. Weak and comparable antiferromagnetic couplings are observed in the nearest neighbors of 1 – 3 , which are cooperatively transmitted either by short carboxylate and/or atz heterobridges or by weak non‐covalent interactions. 相似文献
10.
The synthesis of 3,3‐dimethylmorpholine‐2,5‐diones 4a was achieved conveniently via the ‘direct amide cyclization’ of the linear precursors of type 3 , which were prepared by coupling of 2,2‐dimethyl‐2H‐azirin‐3‐amines 2 with 2‐hydroxyalkanoic acids 1 . Thionation of 4a with Lawesson's reagent yielded the corresponding 5‐thioxomorpholin‐2‐ones 10 and morpholine‐2,5‐dithiones 11 , respectively, depending on the reaction conditions. The structures of 3aa, 4aa, 10a , and 11a were established by X‐ray crystallography. All attempts to prepare S‐containing morpholine‐2,5‐dione analogs or thiomorpholine‐2,5‐diones by cyclization of corresponding S‐containing precursors were unsuccessful and led to various other products. The structures of some of them have also been established by X‐ray crystallography. 相似文献
11.
Kazuhiro Kobayashi Toshihide Komatsu Yuki Yokoi Hisatoshi Konishi 《Helvetica chimica acta》2011,94(1):67-72
An efficient synthesis of 3‐alkyl‐3,4‐dihydro‐4‐thioxobenzoquinazolin‐2(1H)‐ones 3 has been accomplished in two steps and in satisfactory yields from 1‐bromo‐2‐fluorobenzenes 1 . Thus, the reaction of 1‐fluoro‐2‐lithiobenzenes, generated by the Br/Li exchange between 1 and BuLi, with alkyl isothiocyanates, gives N‐alkyl‐2‐fluorobenzothioamides 2 , which, in turn, react with a series of isocyanates in the presence of NaH to give the desired products 3 . 相似文献
12.
A Facile Synthesis of 1‐Substituted 3‐Alkoxy‐1H‐isoindoles Based on the Reaction of 2‐(Dialkoxymethyl)phenyllithiums with Nitriles,Followed by Acid‐Catalyzed Cyclization
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A two‐step synthesis of 1‐substituted 3‐alkoxy‐1H‐isoindoles 4 has been developed. Thus, the reaction of 2‐(dialkoxymethyl)phenyllithium compounds, which are easily generated in situ by Br/Li exchange between 1‐bromo‐2‐(dialkoxymethyl)benzenes 1 and BuLi in THF at ?78°, with nitriles afforded [2‐(dialkoxymethyl)phenyl]methanimines 2 , which were treated with a catalytic amount of TsOH?H2O in refluxing CHCl3 to give the desired products in reasonable yields. Similarly, 3‐aryl‐1‐ethoxy‐1‐methyl‐1H‐isoindoles 7 have been prepared starting from 1‐bromo‐2‐(1,1‐diethoxyethyl)benzenes 5 . 相似文献
13.
An efficient method for the preparation of 2‐substituted 4‐aryl‐4,5‐dihydro‐3,1‐benzoxazepine derivatives under mild conditions has been developed. The reaction of 2‐(2‐aminophenyl)ethanols 1 with acid chlorides in the presence of excess Et3N in THF at room temperature gave the corresponding N‐acylated intermediates 2 , which were dehydrated by treatment with POCl3 to give 2‐substituted 4‐aryl‐4,5‐dihydro‐3,1‐benzoxazepines 3 in a one‐pot reaction. 相似文献
14.
2,3‐Dihydro‐4H‐thiopyrano[2,3‐b]pyridin‐4‐ones 4 were prepared by a three‐step sequence from commercially available 2‐chloropyridine ( 1 ). Thus, successive treatment of 1 with iPr2NLi (LDA) and α,β‐unsaturated aldehydes gave 1‐(2‐chloropyridin‐3‐yl)alk‐2‐en‐1‐ols 2 , which were oxidized with MnO2 to 1‐(2‐chloropyridin‐3‐yl)alk‐2‐en‐1‐ones 3 . The reactions of 3 with NaSH?n H2O proceeded smoothly at 0° in DMF to provide the desired thiopyranopyridinones. Similarly, 2,3‐dihydro‐4H‐thiopyrano[2,3‐c]pyridin‐4‐ones 8 and 2,3‐dihydro‐4H‐thiopyrano[3,2‐c]pyridin‐4‐ones 12 were obtained starting from 3‐chloropyridine ( 5 ) and 4‐chloropyridine ( 9 ), respectively. 相似文献
15.
Justin E. Cochran Elizabeth Amir Kulandaivelu Sivanandan Sung‐Yu Ku Jung Hwa Seo Brian A. Collins John R. Tumbleston Michael F. Toney Harald Ade Craig J. Hawker Michael L. Chabinyc 《Journal of Polymer Science.Polymer Physics》2013,51(1):48-56
An alkylated semiconducting polymer comprising alternating bithiophene‐[all]‐S,S‐dioxide and aromatic monothiophene units in the polymer backbone was synthesized with the intent of modifying the energy gap and lowest unoccupied molecular orbital for use as a stable n‐type semiconductor. Films spun from this semiconducting polymer were characterized utilizing X‐ray scattering, near edge X‐ray absorption fine structure spectroscopy, ultraviolet photoelectron spectroscopy, and thin‐film field effect transistors to determine how oxidation of the thiophene ring systems impacts the structural and electronic properties of the polymer. The thiophene‐S,S‐dioxide polymers have lower optical and electrical band gaps than corresponding thiophene polymers. X‐ray scattering results indicate that the polymers are well ordered with the π–π stacking distances increased by 0.4 Å relative to analogous thiophene polymers. The electrical stability of these polymers is poor in transistors with a drop in the field effect mobility by approximately one order of magnitude upon addition of just 5% of the thiophene‐S,S‐dioxide unit in a copolymer with thiophene. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013 相似文献
16.
2, 4‐Dimethylpenta‐1, 3‐diene and 2, 4‐Dimethylpentadienyl Complexes of Rhodium and Iridium The complexes [(η4‐C7H12)RhCl]2 ( 1 ) (C7H12 = 2, 4‐dimethylpenta‐1, 3‐diene) and [(η4‐C7H12)2IrCl] ( 2 ) were obtained by interaction of C7H12 with [(η2‐C2H4)2RhCl]2 and [(η2‐cyclooctene)2IrCl]2, respectively. The reaction of 1 or 2 with CpTl (Cp = η5‐C5H5) yields the compounds [CpM(η4‐C7H12)] ( 3a : M = Rh; 3b : M = Ir). The hydride abstraction at the pentadiene ligand of 3a , b with Ph3CBF4 proceeds differently depending on the solvent. In acetone or THF the “half‐open” metallocenium complexes [CpM(η5‐C7H11)]BF4 ( 4a : M = Rh; 4b : M = Ir) are obtained exclusively. In dichloromethane mixtures are produced which additionally contain the species [(η5‐C7H11)M(η5‐C5H4CPh3)]BF4 ( 5a : M = Rh; 5b : M = Ir) formed by electrophilic substitution at the Cp ring, as well as the η3‐2, 4‐dimethylpentenyl compound [(η3‐C7H13)Rh{η5‐C5H3(CPh3)2}]BF4 ( 6 ). By interaction of 2, 4‐dimethylpentadienyl potassium with 1 or 2 the complexes [(η4‐C7H12)M(η5‐C7H11)] ( 7a : M = Rh; 7b : M = Ir) are generated which show dynamic behaviour in solution; however, attempts to synthesize the “open” metallocenium cations [(η5‐C7H11)2M]+ by hydride abstraction from 7a , b failed. The new compounds were characterized by elemental analysis and spectroscopically, 4b and 5a also by X‐ray structure analysis. 相似文献
17.
One‐Pot Synthesis of N,N‐Disubstituted (Z)‐4‐(Halomethylidene)‐4H‐3,1‐benzothiazin‐2‐amines from 2‐(2,2‐Dihaloethenyl)phenyl Isothiocyanates and Secondary Amines
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Kazuhiro Kobayashi Kazuya Yamane Ippei Nozawa Kosuke Ezaki 《Helvetica chimica acta》2014,97(3):315-320
We have developed a one‐pot procedure for the preparation of N,N‐disubstituted (Z)‐4‐(halomethylidene)‐4H‐3,1‐benzothiazin‐2‐amines 3 from 2‐(2,2‐dihaloethenyl)phenyl isothiocyanates 1 , easily accessible from known 2‐(2,2‐dihaloethenyl)benzenamines by a three‐step sequence, and secondary amines. Thus, the isothiocyanates 1 react with secondary amines to afford the corresponding thiourea derivatives, of which the treatment with NaH provides the desired products. 相似文献
18.
Heating a mixture of 1, 3-diiodo-1, 1, 3, 3-tetrafluoropropane (2), K2CO3, pyridinium bromides (3) in CH3CN at 65℃ for 10 h gives the corresponding trifluoromethylindolizines. 相似文献
19.
2‐(1‐Aryl‐2‐methoxyethenyl)benzaldehydes 2 , obtained by successive treatment of 1‐(1‐aryl‐2‐methoxyethenyl)‐2‐bromobenzenes 1 with BuLi and 1‐formylpiperidine, were transformed to the corresponding phenylhydrazones 3 on treatment with PhNHNH2. When these hydrazones were allowed to react with conc. HBr, cyclization, followed by dehydrogenation with air occurred, furnished 3‐aryl‐2‐methoxyinden‐1‐one (Z)‐phenylhydrazones 4 . 相似文献
20.
Xiaoying Xu Xiang Li Anjie Wang Yinyong Sun W. Bernd Schweizer Roel Prins 《Helvetica chimica acta》2011,94(10):1754-1763
1,2,3,4‐Tetrahydro‐4,6‐dimethyldibenzothiophene was prepared by coupling 2‐bromo‐3‐methylcyclohexanone with 2‐methylbenzenethiol and annulating the product with the aid of polyphosphoric acid. A mixture of 1,2,3,4‐tetrahydro‐4,6‐dimethyldibenzothiophene and 4,6‐dimethyldibenzothiophene was prepared by coupling 2‐bromo‐3‐methylcyclohex‐2‐en‐1‐one with 2‐methylbenzenethiol and annulating the product with the aid of polyphosphoric acid. 2‐Bromo‐3‐methylcyclohexanone was synthesized by conjugate addition of Me3Al to 2‐bromocyclohex‐2‐en‐1‐one with CuBr as catalyst and 2‐bromo‐3‐methylcyclohex‐2‐en‐1‐one by bromination? elimination of 3‐methylcyclohex‐2‐en‐1‐one. 1,2,3,4,4a,9b‐Hexahydro‐4,6‐dimethyldibenzothiophene was prepared by reduction of 1,2,3,4‐tetrahydro‐4,6‐dimethyldibenzothiophene with Zn and CF3COOH. 相似文献