123293-65-2Relevant academic research and scientific papers
Synthesis of symmetrical and unsymmetrical triarylpyrylium ions: Via an inverse electron demand Diels-Alder reaction
Fathimath Salfeena,Basavaraja,Ashitha,Kumar, V. Praveen,Varughese, Sunil,Suresh, Cherumuttathu H.,Sasidhar
, p. 12463 - 12466 (2018)
BF3·OEt2 mediated inverse electron demand Diels-Alder (IEDDA) reaction of chalcones with aryl acetylenes is reported for the synthesis of symmetrical and unsymmetrical 2,4,6-triarylpyrylium ions. The protocol provides an effective one-pot method for the utilization of readily available simple substrates under mild reaction conditions leading to a diverse array of pyrylium ions in moderately good yield.
Transition-Metal-Free Catalytic Formal Hydroacylation of Terminal Alkynes
Yatabe, Takafumi,Mizuno, Noritaka,Yamaguchi, Kazuya
, p. 11564 - 11569 (2018/11/23)
Although hydroacylation is a very useful reaction for producing ketones from aldehydes with 100% atom efficiency, classical Rh-catalyzed hydroacylation presents several problems, including the need for transition metal catalysts, unwanted decarbonylation of aldehydes, and difficulty in regioselectivity control. However, formal hydroacylation utilizing the nucleophilicity of terminal alkynes can avoid these problems. In this work, we have achieved transition-metal-free formal hydroacylation of terminal alkynes using an Mg3Al-CO3-layered double hydroxide as a heterogeneous catalyst. This system was applicable to the efficient synthesis of α,β-unsaturated ketones with various substituents, and the catalyst can be reused without a significant loss of catalytic performance.
Studies on the nuclear magnetic resonance spectra of (E)-1-Aryl-3-(2- and 3-thienyl)-2-propenones and unique observation of 4J and 5J coupling in their 1H-1H COSY
Han Lee, In-Sook,Jeon, Hyun Ju,Lee, Chang Kiu
scheme or table, p. 687 - 692 (2011/12/03)
1H and 13C NMR spectra of series of (E)-1-aryl-(2- and 3-thienyl)-2-propenones, that are aldol condensation products between 2- and 3-thiophenecarbaldehydes and m- and p-substituted acetophenones, were examined to make complete assig
Formation of γ-oxoacids and 1 H-pyrrol-2(5 H)-ones from α,β-unsaturated ketones and ethyl nitroacetate
Aginagalde, Maialen,Bello, Tamara,Masdeu, Carme,Vara, Yosu,Arrieta, Ana,Cossio, Fernando P.
supporting information; experimental part, p. 7435 - 7438 (2010/12/25)
Michael addition of ethyl nitroacetate on α,β-unsaturated ketones followed by Nef oxidation under hydrolytic conditions yields γ-oxoacids instead of the corresponding α,δ-dioxoesters. A concerted decarboxylation step is proposed on the basis of computational results. Finally, conversion of the γ-ketoacids thus prepared into 1H-pyrrol-2(5H)-ones by reaction with primary amines under Paal-Knorr conditions is also reported.
2,4,6-Trisubstituted pyridines: Synthesis, topoisomerase I and II inhibitory activity, cytotoxicity, and structure-activity relationship
Basnet, Arjun,Thapa, Pritam,Karki, Radha,Na, Younghwa,Jahng, Yurngdong,Jeong, Byeong-Seon,Jeong, Tae Cheon,Lee, Chong-Soon,Lee, Eung-Seok
, p. 4351 - 4359 (2008/03/12)
Designed and synthesized were a series of pyridines substituted at 2, 4, and 6 positions with various 5- or 6-memberd heteroaromatics as antitumor agents. They were evaluated their topoisomerase I and II inhibitory activities along with cytotoxicities against several human cancer cell lines. Among the prepared compounds, 10-20 showed significant topoisomerase I or II inhibitory activities, and 21-26 showed considerable cytotoxicities against several human cancer cell lines. Structure-activity relationship study indicates that 4′-pyridine at 6-position of central pyridine plays a key role in biological activity.
Solution phase synthesis of a spiro[pyrrolidine-2,3'-oxindole] library via a three component 1,3-dipolar cycloaddition reaction
Fokas, Demosthenes,Ryan, William J.,Casebier, David S.,Coffen, David L.
, p. 2235 - 2238 (2007/10/03)
A combinatorial library of 26,500 spiro[pyrrolidine,-2,3-oxindoles] was prepared in a single-compound format by a facile intermolecular 1,3-dipolar cycloaddition. An azomethine ylide, generated by the decarboxylative condensation of an isatin 1 with an α-amino acid 2, was trapped by a transchalcone 3 to afford heterocycles of the general structure 4. The regio- and stereochemistry of a representative product was determined by single crystal X-ray structure.
Replacement Substituent Constants for Simple Heterocycles
Robinson, Charles N.,Wiseman, Leonard J. Jr.,Slater, Carl D.
, p. 4103 - 4112 (2007/10/02)
13C nmr absorptions are reported for the β-vinylic carbon atoms in 15 series of ethylenes bearing heterocyclic substituents.The data are used to establish the best single-parameter substituent constants, ?13, for the various heterocycles as replacements for para-substituted benzenes.Also reported are replacement dual substituent constants, including ?I and the various ?R scales needed in the Taft DSP treatment and those for F and R used in the Swain-Lupton treatment.Values of ?13, F, R, ?I, and ?Ro, respectively, for the various heterocycles as replacements for para-substituted benzenes are as follows: 2-furyl, -1.01 , 0.99, -2.51, 0.65, -0.60; 2-pyrryl, -2.53, 0.52, -5.09, -0.16, -0.62; 2-thienyl, -0.79, 2.49, -3.60, 1.82, -1.08; 3-thienyl, -0.40, 1.04, -1.57, 0.59, -0.39; 2-pyridyl, 0.88, 2.09, -0.24, 1.65, -0.45; 3-pyridyl, 0.60, 0.57, 0.63, 0.35, 0.04; and 4-pyridyl, 1.18, 1.22, 1.09, 0.92, -0.01.The DSP-NLR method of analysis is explored using electron demand parameters, ε, as determined for the vinylic side chains in para-substituted styrenes.
