scholarly journals Synthesis of spiro[dihydropyridine-oxindoles] via three-component reaction of arylamine, isatin and cyclopentane-1,3-dione

2013 ◽  
Vol 9 ◽  
pp. 8-14 ◽  
Author(s):  
Yan Sun ◽  
Jing Sun ◽  
Chao-Guo Yan

A fast and convenient protocol for the synthesis of novel spiro[dihydropyridine-oxindole] derivatives in satisfactory yields was developed by the three-component reactions of arylamine, isatin and cyclopentane-1,3-dione in acetic acid at room temperature. On the other hand the condensation of isatin with two equivalents of cyclopentane-1,3-dione gave 3,3-bis(2-hydroxy-5-oxo-cyclopent-1-enyl)oxindole in high yields. The reaction mechanism and substrate scope of this novel reaction is briefly discussed.

2003 ◽  
Vol 81 (11) ◽  
pp. 1299-1306 ◽  
Author(s):  
Frédéric-Georges Fontaine ◽  
René-Viet Nguyen ◽  
Davit Zargarian

Abstraction of Cl– from the complexes (indenyl)Ni(PPh3)Cl generates cationic species that are effective precatalysts for the hydrosilylation of some olefins and ketones. For instance, the mixture of (1-Me-indenyl)Ni(PPh3)Cl and NaBPh4 (or methylaluminoxane) reacts at room temperature with ca. 100 equiv. each of PhSiH3 and styrene to produce [1-phenyl-1-ethyl](phenyl)silane, PhCH(CH3)(SiPhH2), in 50%–80% yield. The same system can also catalyze the hydrosilylation of 1-hexene and norbornene, but the products arising from these substrates consist of mixtures of regio- and stereoisomers. On the other hand, ketone hydrosilylation is regiospecific, giving the corresponding silyl ethers in high yields. A number of experimental observations have indicated that the initially generated Ni-based cation is not the catalytically active species. Indeed, the cationic initiators may be replaced by LiAlH4 or AlMe3, which generate the corresponding Ni-H or Ni-Me derivatives, respectively. Moreover, the observed regioselectivity for the addition of PhSiH3 to styrene (i.e., predominant addition of the silyl fragment to the α-C) is opposite of what would be expected if the reaction mechanism involved carbocationic intermediates. A new mechanism is proposed in which the active species is a Ni-H species originating from the transfer of H– from PhSiH3 to the initially generated Ni cation. Key words: hydrosilylation, nickel indenyl complexes, cationic complexes, hydride intermediates.


Author(s):  
Shweta Singh ◽  
Sureshbabu Popuri ◽  
Qazi Mohammad Junaid ◽  
Sabiah Shahul Hameed ◽  
Jeyakumar Kandasamy

A wide range of N-tosyl α–ketoamides underwent transamidation with various alkyl amines in the absence of catalyst, base, or additives. On the other hand, transamidation in N-Boc α–ketoamides is achieved...


2012 ◽  
Vol 9 (4) ◽  
pp. 2239-2244 ◽  
Author(s):  
Hossein Anaraki-Ardakani ◽  
Maziar Noei ◽  
Mina Karbalaei-Harofteh ◽  
Shahab Zomorodbakhsh

A new and efficient one-pot synthesis of polysubstituted pyrrole derivatives by three-component reaction between dialkyl acetylenedicarboxylates, triphenylphosphine, 2-aminopyridin derivatives in the presence of arylglyoxals is described. The reactions were performed in dichloromethane at room temperature and neutral conditions and afforded high yields of products.


2020 ◽  
Vol 16 ◽  
pp. 2769-2775
Author(s):  
Tetsuya Sengoku ◽  
Koki Makino ◽  
Ayumi Iijima ◽  
Toshiyasu Inuzuka ◽  
Hidemi Yoda

New synthetic methods for spirolactams bearing an α-methylene-γ-butyrolactone or its analogous methylene-lactam have been developed. The allylation of γ-phenylthio-functionalized γ-lactams with 2-(acetoxy)methyl acrylamides was accomplished by using 2.5 equivalents of NaH to give the corresponding adducts in excellent yields. The remaining phenylthio group was substituted with a hydroxy group by treatment with CuBr, and the resulting γ-hydroxyamides were cyclized under acidic conditions to afford the corresponding methylene-lactam-fused spirolactams in high yields. On the other hand, methylene-lactone-fused spirolactams could be delivered from the allyl adducts in high yields through a sequential N-Boc protection/desulfinative lactonization.


Synthesis ◽  
2019 ◽  
Vol 52 (05) ◽  
pp. 744-754
Author(s):  
Yoona Song ◽  
Soyun Lee ◽  
Palash Dutta ◽  
Jae-Sang Ryu

A copper(I)-mediated tandem three-component reaction using alkynes, azides, allyl iodides, CuI and NaNH2 is developed. The reactions proceed smoothly at room temperature to afford 5-allyl-1,2,3-triazoles, which can be further converted into 1,2,3-triazole-fused tricyclic scaffolds. This method features an efficient one-pot cascade route using commercial alkynes and affords the corresponding 5-allyl-1,2,3-triazoles with high yields and good selectivity under mild reaction conditions.


2019 ◽  
Vol 15 ◽  
pp. 874-880
Author(s):  
Razieh Navari ◽  
Saeed Balalaie ◽  
Saber Mehrparvar ◽  
Fatemeh Darvish ◽  
Frank Rominger ◽  
...  

An efficient approach for the synthesis of pyrazolopyridines containing the aminochromane motif through a base-catalyzed cyclization reaction is reported. The synthesis was carried out through a three-component reaction of (arylhydrazono)methyl-4H-chromen-4-one, malononitrile, primary amines in the presence of Et3N at room temperature. However, carrying out the reaction under the same conditions without base led to a fused chromanyl-cyanopyridine. High selectivity, high atom economy, and good to high yields in addition to mild reaction conditions are the advantages of this approach.


1977 ◽  
Vol 32 (6) ◽  
pp. 701-704 ◽  
Author(s):  
Gert Kollenz ◽  
Erich Ziegler ◽  
Walter Ott ◽  
Gert Kriwetz

4-Benzoyl-5-phenyl-2,3-dihydrofuran-2,3-dione (1) reacts with aldehydes or ketones via the acylketene-intermediate (2) yielding the 1,3-dioxin-4-ones (3). The aldehyde derivatives (3 a-e) can be converted into the anilino-chalcone (5) or the anilino acrylic acid (6) by treating with aniline at 20 °C. 6 and diazomethane combine to the acrylic acid methyl ester (7), which by heating (200 °C) is cyclisized to the quinolin-4-ole (8). On the other hand, the keto derivatives 3f-h and aniline give the dibenzoyl acetic acid anilide (9).


SynOpen ◽  
2017 ◽  
Vol 01 (01) ◽  
pp. 0076-0083 ◽  
Author(s):  
Jihui Li ◽  
Weiguang Yu ◽  
Yifeng Hou ◽  
Wenxing Fu ◽  
Shuying Xu ◽  
...  

A copper-catalysed, three-component reaction involving cyan­amides, fluoroalcohols and diaryliodonium triflates is disclosed for the synthesis of O-fluoroalkylisoureas. Various O-fluoroalkylisoureas were obtained in good yields by using simple and readily available substrates. Moreover, C–H activation of O-fluoroalkylisoureas mediated by PhI(OAc)2 was established to obtain 2-fluoroalkoxybenzimidazoles in high yields at room temperature.


2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Sarka Msallamova ◽  
Milan Kouril ◽  
Kristyna Charlotte Strachotova ◽  
Jan Stoulil ◽  
Kateryna Popova ◽  
...  

Abstract Historical museums and depositories contain collections with a number of lead objects or historical documents with lead seals. Lead is a metal which has good corrosion resistance under atmospheric conditions. On the other hand, lead corrodes in an activity in an environment which contains volatile organic compounds (mainly acetic acid and formic acid). In a depository environment, sources of volatile compounds can be the historical documents themselves, wood, plastics (those made from cellulose acetate), polyvinyl acetate adhesives, varnishes, oil or emulsion paints, etc. The aim of this work was to compare the efficiency of commercial adsorbents (activated carbon, activated alumina, zeolite, and bentonite) in the acetic acid vapours. The lead corrosion rates were determined by using lead resistometric probes. Activated alumina and activated carbon were found to be the most effective adsorbents of acetic acid vapours. On the other hand, the available zeolite had the worst sorption ability compared with the other tested substances.


PEDIATRICS ◽  
1973 ◽  
Vol 52 (2) ◽  
pp. 309-309
Author(s):  
C. Warren Bierman

Dr. Bergner is quite correct in pointing out that skin testing with a freshly prepared penicillin solution will select out only about 30% of patients who are anaphylacticly sensitive to penicillin.1 On the other hand, the use of a sterile solution of benzylpenicillin diluted with alkaline buffered saline (pH 7.6) and permitted to stand at room temperature for at least two weeks appreciably increases the number of patients so detected.2 We would agree that the availability of a penicilloyl polylysine (PPL) testing solution and a stabilized minor determinent mixture (MDM) would greatly enhance the armamentarium of the clinician to detect anaphylactic sensitivity to penicillin.3


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