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1.
The highly reactive 1 : 1 intermediate generated in the reaction between dialkyl acetylenedicarboxylate (=but‐2‐ynedioic acid dialkyl ester) 4 and triphenylphosphine was trapped by 2‐amino‐4‐oxo‐4H‐1‐benzopyran‐3‐carboxaldehydes 5 to yield highly functionalized dialkyl‐1,5‐dihydro‐5‐oxo‐1‐phenyl‐2H‐[1]benzopyrano[2,3‐b]pyridine‐2,3‐dicarboxylates in high yield. 相似文献
2.
Ali Ramazani Morteza Rouhani Aram Rezaei Nahid Shajari Ali Souldozi 《Helvetica chimica acta》2011,94(2):282-288
Reactions of biacetyl (=butane‐2,3‐dione) with (N‐isocyanimino)triphenylphosphorane in the presence of aromatic carboxylic acids proceed smoothly at room temperature and under neutral conditions to afford 3‐(5‐aryl‐1,3,4‐oxadiazol‐2‐yl)‐3‐hydroxybutan‐2‐one derivatives in high yields. 相似文献
3.
Afsaneh Feiz Ghazaleh Imani Shakibaei Zahra Yasaei Hamid Reza Khavasi Ayoob Bazgir 《Helvetica chimica acta》2011,94(9):1628-1637
A new four‐component synthesis of spiro[4H‐indeno[1,2‐b]pyridine‐4,3′‐[3H]indoles] and spiro[acenaphthylene‐1(2H),4′‐[4H‐indeno[1,2‐b]pyridines] by the reaction of indane‐1,3‐dione, 1,3‐dicarbonyl compounds, isatins (=1H‐indole‐2,3‐diones) or acenaphthylene‐1,2‐dione, and AcONH4 in refluxing toluene in the presence of a catalytic amount of pyridine is reported. 相似文献
4.
Isamu Shiina Kenya Nakata Keisuke Ono Teruaki Mukaiyama 《Helvetica chimica acta》2012,95(10):1891-1911
Pyridine‐3‐carboxylic anhydride (3‐PCA) was found to function as an efficient coupling reagent for the preparation of carboxylic esters from various carboxylic acids with alcohols under mild conditions by a simple experimental procedure. This novel condensation reagent 3‐PCA was applicable not only for the synthesis of achiral carboxylic esters catalyzed by 4‐(dimethylamino)pyridine (DMAP) but also for the production of chiral carboxylic esters by the combination of chiral nucleophilic catalyst, such as tetramisole (=2,3,5,6‐tetrahydro‐6‐phenylimidazo[2,1‐b][1,3]thiazole) derivatives. An efficient kinetic resolution of racemic benzylic alcohols with achiral carboxylic acids was achieved by using 3‐PCA in the presence of (R)‐benzotetramisole ((R)‐BTM), and a variety of optically active carboxylic esters were produced with high enantiomeric excesses by this new chiral induction system without using a tertiary amine. 相似文献
5.
An efficient one‐pot synthesis of 3‐[(4,5‐dihydro‐1H‐pyrrol‐3‐yl)carbonyl]‐2H‐chromen‐2‐one (=3‐[(4,5‐dihydro‐1H‐pyrrol‐3yl)carbonyl]‐2H‐1‐benzopyran‐2‐one) derivatives 4 by a four‐component reaction of a salicylaldehyde 1 , 4‐hydroxy‐6‐methyl‐2H‐pyran‐2‐one, a benzylamine 2 , and a diaroylacetylene (=1,4‐diarylbut‐2‐yne‐1,4‐dione) 3 in EtOH is reported. This new protocol has the advantages of high yields (Table), and convenient operation. The structures of these coumarin (=2H‐1‐benzopyran‐2‐one) derivatives, which are important compounds in organic chemistry, were confirmed spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this reaction is proposed (Scheme 2). 相似文献
6.
An efficient protocol for the one‐pot reaction of isatoic anhydride (=1,2‐dihydro‐4H‐3,1‐benzoxazine‐2,4‐dione), primary alkylamines, and heterocumulenes (isothiocyanates and isocyanates) in H2O catalyzed by magnetically recoverable Fe3O4 nanoparticles is described. 相似文献
7.
A Ph3P‐catalyzed cyclization of α‐halogeno ketones 2 with dialkyl acetylenedicarboxylates (=dialkyl but‐2‐ynedioates) 3 produced halogenated α,β‐unsaturated γ‐butyrolactone derivatives 4 in good yields (Scheme 1, Table). The presence of electron‐withdrawing groups such as halogen atoms at the α‐position of the ketones was necessary in this reaction. Cyclization of α‐chloro ketones resulted in higher yields than that of the corresponding α‐bromo ketones. Dihalogeno ketones similarly afforded the expected γ‐butyrolactone derivatives in high yields. 相似文献
8.
Mohammad Bayat Nader Zabarjad Shiraz Soheila Shafei Asayesh 《Helvetica chimica acta》2010,93(11):2218-2223
An effective route to functionalized 2H‐chromene (=2H‐1‐benzopyran) derivatives 4 is described (Scheme 1). This involves the reaction of a 1,1‐diactivated alkene, resulting from the reaction of dimedone (=5,5‐dimethylcyclohexane‐1,3‐dione; 1a ) with methyl chloroglyoxylate (ClC(O)COOMe), benzyl carbonochloridate (ClC(O)OCH2Ph) or 3,5‐dinitrobenzoyl chloride (3,5‐(NO2)2C6H3C(O)Cl), and a dialkyl acetylenedicarboxylate (=dialkyl but‐2‐ynedioate) in the presence of Ph3P which undergo intramolecular Wittig reaction to produce 2H‐chromene derivatives (Scheme 1). 相似文献
9.
Ali Ramazani Nader Noshiranzadeh Alieh Ghamkhari Katarzyna Ślepokura Tadeusz Lis 《Helvetica chimica acta》2008,91(12):2252-2261
Highly reactive 1 : 1 intermediates were produced in the reaction of Ph3P and dialkyl acetylenedicarboxylates (=dialkyl but‐2‐ynedioates). Protonation of these intermediates by alcohols (2,2,2‐trichloroethanol, propargyl alcohol (=prop‐2‐yn‐1‐ol), MeOH, benzyl alcohol, and allyl alcohol (=prop‐2‐en‐1‐ol) led to vinyltriphenylphosphonium salts 4 , which underwent a Michael addition reaction with the conjugate base to produce the corresponding stabilized phosphonium ylides 5 (Scheme). Wittig reaction of the stabilized phosphonium ylides with ninhydrin ( 6 ) led to the corresponding densely functionalized 2H‐indeno[2,1‐b]furans 10 in fairly good yields (Table 1). The structures of the final products were confirmed by IR, 1H‐ and 13C‐NMR spectroscopy, and mass spectrometry. The configuration of dimethyl 8,8a‐dihydro‐8‐oxo‐8a‐(2,2,2‐trichloroethoxy)‐2H‐indeno[2,1‐b]furan‐2,3‐dicarboxylate ( 10a ) was established by a single‐crystal X‐ray structure determination, establishing that the one‐pot multicomponent condensation reaction was completely diastereoselective. 相似文献
10.
4-Pentyne-1,3-dione system having various substituents was synthesized in two steps and the cyclization behavior of the obtained 1,3-dicarbonyl compounds was examined. γ-Pyrones and 2-alkylidene-2,3-dihydro-3-furanones were obtained by the triethylamine-catalyzed cyclization of the 4-pentyne-1,3-dione system having a diketone moiety. Furthermore, a phenol derivative was obtained in the case of 4-pentyne-1,3-dione system having an ester moiety. Thus, it was found that the kind of substituents in the 4-pentyne-1,3-dione system remarkably influenced the selectivity in the cyclization. 相似文献
11.
An efficient one‐pot synthesis of pyrido[1,2‐a]‐fused 1,3‐diazaheterocyclic compounds by three‐component reaction of diamine, nitroketene dithioacetal (=1,1‐bis(methylsulfanyl)‐2‐nitroethene), and electron‐poor itaconic anhydride (=2‐methylidenesuccinic anhydride=2‐methylidenebutanedioic anhydride) in aqueous EtOH is reported. This protocol has the advantages of easiness, higher yields, and shorter reaction times. The 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 2). 相似文献
12.
The three‐component reaction of the zwitterions generated from dialkyl acetylenedicarboxylates (=dialkyl but‐2‐ynedioates and triphenylphosphine (Ph3P) with isoindoline‐1,3‐diimine (=1H‐isoindole‐1,3(2H)‐diimine) is described (Scheme 1). This reaction affords the corresponding special type of substituted dihydropyrimido[2,1‐a]isoindole derivatives in good yields without using any catalyst and activation (Table). 相似文献
13.
Maryam Sabbaghan Issa Yavari Zinatossadat Hossaini Sanaz Souri 《Helvetica chimica acta》2010,93(5):946-950
A synthesis of quinoline derivatives is described via reaction between ethyl bromopyruvate (=ethyl 3‐bromo‐2‐oxopropanoate), acetylenedicarboxylate, and isatin (=1H‐indole‐2,3‐dione) in the presence of NaH as a base. Also, these reactions were performed without ethyl bromopyruvate. The reaction in the presence of ethyl bromopyruvate provides regioselectively a quinoline with the ethyl ester group in 4‐position. In the absence of ethyl bromopyruvate, the reaction leads to functionalized quinolines with the same ester groups in 2‐, 3‐, and 4‐positions. 相似文献
14.
The title compounds, the P(3)‐axially and P(3)‐equatorially substituted cis‐ and trans‐configured 8‐benzyl‐3‐fluoro‐2,4‐dioxa‐8‐aza‐3‐phosphadecalin 3‐oxides (=8‐benzyl‐3‐fluoro‐2,4‐dioxa‐8‐aza‐3‐phosphabicyclo[4.4.0]decane 3‐oxides=2‐fluorohexahydro‐6‐(phenylmethyl)‐4H‐1,3,2‐dioxaphosphorino[5,4‐c]pyridine 2‐oxides) were prepared (ee>98%) and fully characterized (Schemes 2 and 3). The absolute configurations were established from that of their precursors, the enantiomerically pure cis‐ and trans‐1‐benzyl‐4‐hydroxypiperidine‐3‐methanols which were unambiguously assigned. Being configuratively fixed and conformationally constrained phosphorus analogues of acetyl γ‐homocholine (=3‐(acetyloxy)‐N,N,N‐trimethylpropan‐1‐aminium), they are suitable probes for the investigation of molecular interactions with acetylcholinesterase. As determined by kinetic methods, all of the compounds are weak inhibitors of the enzyme. 相似文献
15.
《中国化学》2017,35(9):1422-1430
The base promoted three‐component reaction of β‐ enamino imide, malononitrile and various cyclic α‐ diketones in acetonitrile showed interesting molecular diversity. The reactions with acenaphthylene‐1,2‐dione and ninhydrin afforded functionalized spiro[indene‐2,4'‐pyrrolo[3,4‐b ]pyridines] and spiro[acenaphthylene‐1,4'‐pyrrolo[3,4‐b ]pyridines] in good yields. The similar reaction of phenanthrene‐9,10‐dione resulted in the formation of the unexpected complex phenanthro[9',10':4,5]furo[2,3‐c ]pyrrolo[3,4‐b ]pyrroles in satisfactory yields. 相似文献
16.
M. Z. Kassaee Hassan Masrouri Farnaz Movahedi Tayyebeh Partovi 《Helvetica chimica acta》2008,91(2):227-231
A convenient one‐pot four‐component synthesis of tetrasubstituted pyrroles was carried out through the reaction of butane‐2,3‐dione with α‐aminophosphorous ylides, obtained in situ from the 1 : 1 : 1 addition reaction between triphenylphosphine, dialkyl acetylenedicarboxylate, and ammonium acetate. 相似文献
17.
α‐Imidazolformylarylhydrazine 2 and α‐[1,2,4]triazolformylarylhydrazine 3 have been synthesized through the nucleophilic substitution reaction of 1 with imidazole and 1,2,4‐triazole, respectively. 2,2′‐Diaryl‐2H,2′H‐[4,4′]bi[[1,2,4]‐triazolyl]‐3,3′‐dione 4 was obtained from the cycloaddition of α‐chloroformylarylhydrazine hydrochloride 1 with 1,2,4‐triazole at 60 °C and in absence of n‐Bu3N. The inducing factor for cycloaddition of 1 with 1,2,4‐triazole was ascertained as hydrogen ion by the formation of 4 from the reaction of 3 with hydrochloric acid. 4 was also acquired from the reaction of 3 with 1 and this could confirm the reaction route for cycloaddition of 1 with 1,2,4‐triazole. Some acylation reagents were applied to induce the cyclization reaction of 2 and 3.1 possessing chloroformyl group could induce the cyclization of 2 to give 2‐aryl‐4‐(2‐aryl‐4‐vinyl‐semicarbazide‐4‐yl)‐2,4‐dihydro‐[1,2,4]‐triazol‐3‐one 6. 7 was obtained from the cyclization of 2 induced by some acyl chlorides. Acetic acid anhydride like acetyl chloride also could react with 2 to produce 7D . 5‐Substituted‐3‐aryl‐3H‐[1,3,4]oxadiazol‐2‐one 8 was produced from the cyclization reaction of 3 induced by some acyl chlorides or acetic acid anhydride. The 1,2,4‐triazole group of 3 played a role as a leaving group in the course of cyclization reaction. This was confirmed by the same product 8 which was acquired from the reaction of 1 , possessing a better leaving group: Cl, with some acyl chlorides or acetic acid anhydride. 相似文献
18.
One‐Pot Synthesis of Novel Pyrrolo[1,2‐a]quinoxaline‐4(5H)‐ones Using Benzene‐1,2‐diamine,Acetylenedicarboxylates, and β‐Nitrostyrene Derivatives
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The reaction between a variety of o‐phenylenediamines (=benzene‐1,2‐diamines), dialkyl acetylenedicarboxylates, and derivatives of nitrostyrene (=(E)‐(2‐nitroethenyl)benzene) in the presence of sulfamic acid (SA; H3NSO3) as catalyst led to the corresponding pyrrolo[1,2‐a]quinoxaline‐4(5H)‐one derivatives in high yields. 相似文献
19.
Kamal M. El‐Shaieb 《中国化学会会志》2007,54(5):1353-1358
When 2,3‐dichloro‐1,4‐naphthoquinone (DCHNQ) ( 1 ) is allowed to react with 1‐phenylbiguanide (PBG) ( 2 ), 4‐chloro‐2,5‐dihydro‐2,5‐dioxonaphtho[1,2‐d]imidazole‐3‐carboxylic acid phenyl amide ( 4 ), 6‐chloro‐8‐phenylamino‐9H‐7,9,11‐triaza‐cyclohepta[a]naphthalene‐5,10‐dione ( 5 ) and 4‐dimethyl‐amino‐5,10‐dioxo‐2‐phenylimino‐5,10‐dihydro‐2H‐benzo[g]quinazoline‐1‐carboxylic acid amide ( 6 ) were obtained. While on reacting 1 with 2‐guanidinebenzimidazole (GBI) ( 3 ) the products are 3‐(1H‐benzoimidazol‐2‐yl)‐4‐chloro‐3H‐naphtho[1,2‐d]imidazole‐2,5‐dione ( 7 ) and 3‐[3‐(1H‐benzoimidazol‐2‐yl)‐ureido]‐1,4‐dioxo‐1,4‐dihydronaphthalene‐2‐carboxylic acid dimethylamide ( 8 ). 相似文献
20.
A new and efficient synthesis of 2‐[1‐alkyl‐5,6‐bis(alkoxycarbonyl)‐1,2,3,4‐tetrahydro‐2‐oxopyridin‐3‐yl]acetic acid derivatives by a one‐pot three‐component reaction between primary amine, dialkyl acetylenedicarboxylate, and itaconic anhydride (=3,4‐dihydro‐3‐methylidenefuran‐2,5‐dione) is reported. The reaction was performed without catalyst and under solvent‐free conditions with excellent yields. Notably, the ready availability of the starting materials, and the high level of practicability of the reaction and workup make this approach an attractive complementary method to access to unknown 2‐[1‐alkyl‐5,6‐bis(alkoxycarbonyl)‐1,2,3,4‐tetrahydro‐2‐oxopyridin‐3‐yl]acetic acid derivatives. The structures were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this type of domino Michael addition? cyclization reaction is proposed (Scheme 2). 相似文献