Topic
Bicyclic molecule
About: Bicyclic molecule is a research topic. Over the lifetime, 29587 publications have been published within this topic receiving 451252 citations. The topic is also known as: bicyclic molecule.
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TL;DR: Among these compounds, the guanosine analogues 7a and 20a showed significant activity against measles in vitro and were found to exhibit moderate antitumor activity in vitro against L1210 and P388 leukemia.
Abstract: Several 3,4,6-trisubstituted pyrazolo[3,4-d]pyrimidine ribonucleosides were prepared and tested for their biological activity. High-temperature glycosylation of 3,6-dibromoallopurinol with 1-O-acetyl-2,3,5-tri-O-benzoyl-D-ribofuranose in the presence of BF3 X OEt2, followed by ammonolysis, provided 6-amino-3-bromo-1-beta-D-ribofuranosylpyrazolo-[3,4-d]pyrimidin-4(5H)-on e. Similar glycosylation of either 3-bromo-4(5H)-oxopyrazolo [3,4-d]pyrimidin-6-yl methyl sulfoxide or 6-amino-3-bromopyrazolo [3,4-d]pyrimidin-4(5H)-one, and subsequent ammonolysis, also gave 7a. The structural assignment of 7a was on the basis of spectral studies, as well as its conversion to the reported guanosine analogue 1d. Application of this glycosylation procedure to 6-(methylthio)-4(5H)-oxopyrazolo[3,4-d]pyrimidine-3-carboxamide gave the corresponding N-1 glycosyl derivative. Dethiation and debenzoylation of 16a provided an alternate route to the recently reported 3-carbamoylallopurinol ribonucleoside thus confirming the structural assignment of 16a and the nucleosides derived therefrom. Oxidation of 16a and subsequent ammonolysis afforded 6-amino-1-beta-D-ribofuranosyl-4(5H)-oxopyrazolo[3, 4-d]pyrimidine-3-carboxamide. Alkaline treatment of 15a gave 6-azacadeguomycin. Acetylation of 15a, followed by dehydration with phosgene, provided the versatile intermediate 6-amino-1-(2,3,5-tri-O-acetyl-beta-D-ribofuranosyl)-4(5H)-oxopyrazolo [3, 4-d]pyrimidine-3-carbonitrile. Deacetylation of 19 gave 6-amino-1-beta-D-ribofuranosyl-4(5H)-oxopyrazolo[3, 4-d]pyrimidine-3-carbonitrile. Reaction of 19 with H2S gave 6-amino-1-beta-D-ribofuranosyl-4(5H)-oxopyrazolo[3, 4-d]pyrimidine-3-thiocarboxamide. All of these compounds were tested in vitro against certain viruses and tumor cells. Among these compounds, the guanosine analogues 7a and 20a showed significant activity against measles in vitro and were found to exhibit moderate antitumor activity in vitro against L1210 and P388 leukemia. 6-Azacadeguomycin and all other compounds were inactive against the viruses and tumor cells tested in vitro.
112 citations
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TL;DR: In this article, the 1,1-organoboration reactions tolerate various functional groups at the alkyne as well as at the metal, and the characterization of intermediates and final products by X-ray structural analysis and by multinuclear magnetic resonance spectroscopy (NMR).
Abstract: Metallacyclopentadienes (metalloles) containing M = Si, Ge, Sn, Pb, Ti, Pt can be prepared by 1,1-organoboration of alkyn-1-ylmetal compounds LnMCCR1(R1 = H, alkyl, aryl, silyl, etc; L depends on M, and can be hydrogen, alkyl, aryl, Cl, Br, amino groups, a chelating diphosphane, and one or more L can be again alkynyl groups). These reactions proceed via activation of the MC bond(s) by an electron-deficient triorganoborane BR3 (R = alkyl, aryl; non-cyclic, monocyclic, bicyclic, and tricyclic boranes), at first intermolecular and then intramolecular. In the course of these reactions, the MC bonds are cleaved, zwitterionic alkynylborate-like intermediates are formed, in which the metal-containing fragments are coordinated side-on to the CC bonds. In most cases, the 1,1-organoboration reactions tolerate various functional groups at the alkyne as well as at the metal. The characterization of intermediates and final products by X-ray structural analysis and by multinuclear magnetic resonance spectroscopy (NMR) is documented and described. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:188–208, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20222
112 citations
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TL;DR: Some new 2-alkoxy-3-cyano-4,6-diarylpyridines 3,4 were synthesized by condensation of different alpha,beta-unsaturated ketones 1 with malononitrile 2, followed by cyclization in sodium alkoxide/alcohol system.
112 citations
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112 citations
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06 Aug 2004TL;DR: The aluminum chelate complex for organic EL materials is represented by the general formula (1) and in which the amount of the compound represented by as mentioned in this paper wherein Ar2 is a halogen, as an impurity, is 350 wt.ppm or smaller.
Abstract: A material for organic EL's which is suitable for use as a luminescent-layer material giving an organic EL element less apt to suffer the deterioration in luminance caused by long-term operation and excellent in durability. The aluminum chelate complex for organic EL materials is an aluminum chelate complex which is represented by the general formula (1) and in which the amount of the compound represented by the general formula (1) wherein Ar2 is a halogen, as an impurity, is 350 wt.ppm or smaller. (1) In the formula, Ar1 represents mono- or bicyclic arylene; Ar2 represents mono- or bicyclic aryl; and R1 to R6 each represents hydrogen or a C1-8 hydrocarbon group. Incidentally, the impurity is the compound in which Ar2 is a halogen.
112 citations