- Convenient multigram synthesis of 4-chloropyridine-2,6-dicarbonyl dichloride
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A method amenable to the multigram-scale preparation of 4-chloropyridine-2,6-dicarbonyl dichloride is described. The key transformation is the deoxygenative chlorination of the pyridine N- oxide with oxalyl choride. Georg Thieme Verlag Stuttgart.
- Mitsui, Kazuhiko,Parquette, Jon R.
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- Imidazole derivative used as antiviral agent and use thereof in preparation of medicament
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Disclosed are an antiviral compound and a use thereof in the preparation of a medicament for the treatment of virus infections. Specifically, the present invention relates an imidazole derivative for treating respiratory syncytial virus infection.
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Paragraph 0178; 0183; 0184
(2016/10/07)
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- Enantioselective Photocatalytic [3 + 2] Cycloadditions of Aryl Cyclopropyl Ketones
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Control of stereochemistry in photocycloaddition reactions remains a substantial challenge; almost all successful catalytic examples to date have involved [2 + 2] photocycloadditions of enones. We report a method for the asymmetric [3 + 2] photocycloaddition of aryl cyclopropyl ketones that enables the enantiocontrolled construction of densely substituted cyclopentane structures not synthetically accessible using other catalytic methods. These results show that the dual-catalyst strategy developed in our laboratory broadens synthetic chemists' access to classes of photochemical cycloadditions that have not previously been feasible in enantioselective form.
- Amador, Adrian G.,Sherbrook, Evan M.,Yoon, Tehshik P.
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supporting information
p. 4722 - 4725
(2016/05/10)
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- Novel chiral pyridine N-oxide ligands and their application in the enantioselective catalytic reduction of ketones and the addition of diethylzinc to aldehydes
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Starting from picolinic acids 3 and 4, the amino acid-derived 2- aminoacylpyridine N-oxides 1a,c-e and 2,6-bis(aminoacyl)pyridine N-oxides 2b- e can be prepared in two steps by the coupling of picolinic acid N-oxides 5 and 6 under Appel conditions with the corresponding L-amino acid ester or (1R,2S)-norephedrine. Compounds 1 and 2 were used as chiral ligands in two different asymmetric catalyses. In the catalytic addition of diethylzinc to benzaldehyde 11, low enantioselectivities (2-29percent ee) were obtained regardless of the amino acid moiety. However, the corresponding 2,6- bis(aminoacyl)pyridines 7 and 8 led to increased ee values (55percent ee). In the catalytic reduction of ketones 9a-c to alcohols 10a-c low enantioselectivities were observed for alanine-, valine-, and leucine-derived N-oxides 1a,c and 2b,c. An increase of selectivity was observed for bismethionine ligand 2d (32-38percent ee) relative to that of monomethionine ligand 1d (7-16percent ee). However, mononorephedrine ligand 1e (≤ 64percent ee) and the corresponding bis-norephedrine ligand 2e (≤ 51percent ee) displayed the highest selectivities. The influence of the N-oxide moiety on the enantioselectivity was demonstrated by the observation that 2,6-bis(aminoacyl)pyridines 7 and 8 gave much lower selectivities than the corresponding pyridine N-oxides 2d and e.
- Derdau, Volker,Laschat, Sabine,Hupe, Eike,Ko?nig, Wilfried A.,Dix, Ina,Jones, Peter G.
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p. 1001 - 1007
(2007/10/03)
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- The crystal structures of
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The new heteropolyperoxometalate compounds [NMe4][(Me2AsO2){MoO(O2) 2}2] 1, [NMe4][(Ph2PO2){MoO(O2) 2}2] 2, [NBun4][(Ph2PO2){WO(O 2)2}2] 3 and [NH4][(Ph2PO2){MoO(O2) 2(H2O)}] 4 have been isolated and their crystal structures determined. Compounds 1-3 are dinuclear, whilst compound 4 is mononuclear; in all four structures the metal centre(s) have essentially identical pentagonal-bipyramidal co-ordination geometries with a weak axial ligand trans to an oxo group. The utility of 3 as a catalyst for the oxidation of alkenes, alcohols and tertiary amines with hydrogen peroxide as cooxidant has been studied.
- Gresley, N. Melanie,Griffith, William P.,Parkin, Bernardeta C.,White, Andrew J. P.,Williams, David J.
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p. 2039 - 2045
(2007/10/03)
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- Oligoanthranilamides. Non-peptide subunits that show formation of specific secondary structure
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A family of novel oligomers based on the anthranilamide nucleus has been prepared and shown to form well-defined secondary structural features. 1H NMR and X-ray crystallographic techniques have demonstrated that intramolecular hydrogen bonds play a key role in stabilizing both linear sheet and helical conformational forms.
- Hamuro, Yoshitomo,Geib, Steven J.,Hamilton, Andrew D.
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p. 7529 - 7541
(2007/10/03)
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- Heteropolyperoxo- and Isopolyperoxo-tungstates and -molybdates as Catalysts for the Oxidation of Tertiary Amines, Alkenes and Alcohols
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The catalytic oxidation of tertiary amines to the corresponding N-oxides by 4>(3-) (X = P or As, M = Mo or W) and by (2-) with H2O2 as co-oxidant has been studied.Epoxidation of alkenes and oxidation of alcohols by (2-) with H2O2 as co-oxidant has also been examined and compared with that effected by 4>(3-).A possible structure for (2-) is suggested.
- Bailey, Alan J.,Griffith, William P.,Parkin, Bernardeta C.
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p. 1833 - 1838
(2007/10/02)
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- Incorporation of Quinoline-5,8-quinone Moiety into Polyaza Cavities
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Silica gel supported nitric acid treatment of 2,5-dimethoxybenzaldehyde followed by reduction with iron powder provides 3,6-dimethoxy-2-aminobenzaldehyde.Friedlaender condensation of this species with a variety of ketones and diketones leads to 5,8-dimethoxyquinoline derivatives which may be oxidized by ceric ammonium nitrate (CAN) and pyridine-2,6-dicarboxylic acid N-oxide (PDANO) to the corresponding quinones.The quinone functionality can be incorporated into larger cavities by a selective stepwise Friedlaender approach and the CAN/PDANO oxidation appears to work preferentially for 5,8-dimethoxyquinoline.
- Thummel, Randolph P.,Chirayil, Sara,Hery, Christophe,Lim, Jean-Luc,Wang, Tie-Lin
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p. 1666 - 1671
(2007/10/02)
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