4927-55-3Relevant articles and documents
Rh-catalyzed sequential oxidative C-H activation/annulation with geminal-substituted vinyl acetates to access isoquinolines
Chu, Haoke,Sun, Song,Yu, Jin-Tao,Cheng, Jiang
supporting information, p. 13327 - 13329 (2015/08/24)
The concise synthesis of 3-substituted or non-C3-substituted isoquinolines through Rh-catalyzed sequential oxidative C-H activation/annulation with geminal-substituted vinyl acetates was developed with good functional group tolerance. The protocol was successfully applied to the total synthesis of the natural product papaverine.
Facile method for the large-scale synthesis of 6,7,4′-trihydroxyisoflavanone
Liu, Jing,Yang, Zhangyou,Luo, Shenglin,Hao, Yuhui,Ren, Jiong,Su, Yongping,Wang, Weidong,Li, Rong
supporting information, p. 3296 - 3303 (2015/10/12)
6,7,4′-Trihydroxyisoflavanone, the main source of which is extracted from soybeans, has been found to have diverse significant bioactivities. A large-scale, cost-effective, and facile chemical synthesis of 6,7,4′-trihydroxyisoflavanone is presented herein. Its synthesis is characterized by three steps with an overall yield of 71% and a purity or more than 99.0%. This reaction can be scaled up to multikilogram quantities, providing a solid basis for its further bioactivity studies and drug development. With this same method, 6,7,3′,4′-tetrahydroxyisoflavanone, an analog of 6,7,4′-trihydroxyisoflavanone, also can be largely prepared, indicating this modified synthetic method is potentially available for large-scale synthesis of a broad range of multihydroxyl isoflavanones.
Hexaphenylbenzene-based polymers of intrinsic microporosity
Short, Rhys,Carta, Mariolino,Bezzu, C. Grazia,Fritsch, Detlev,Kariuki, Benson M.,McKeown, Neil B.
supporting information; experimental part, p. 6822 - 6824 (2011/08/08)
Microporous polymers derived from the 1,2- and 1,4-regioisomers of di(3′,4′-dihydroxyphenyl)tetraphenylbenzene have very different properties with the former being composed predominantly of cyclic oligomers whereas the latter is of high molar mass suitable for the formation of robust solvent-cast films of high gas permeability.
Towards a facile synthesis of triarylethanones: Palladium-catalyzed arylation of ketone enolates under homogeneous and heterogeneous conditions
Churruca, Fátima,SanMartin, Raul,Carril, Mónica,Tellitu, Imanol,Domínguez, Esther
, p. 2393 - 2408 (2007/10/03)
The palladium-catalyzed regioselective α-monoarylation of deoxybenzoins and α,α-diarylation of acetophenones provides general, efficient access to 1,2,2-triarylethanones. After a comprehensive search for suitable experimental conditions to optimize such transformations, both reactions are alternatively conducted by means of either commercially available polymer-anchored catalysts or a very simple homogeneous catalytic system, thus avoiding the use of complex ligands. In addition, the synthesis of deoxybenzoins employing polymer-supported fibrous palladium catalysts is reported for the first time, and the excellent catalyst recycling properties suggest applicability to industrial purposes.
The early oxidative biodegradation steps of residual kraft lignin models with laccase
Crestini, Claudia,Argyropoulos, Dimitris S.
, p. 2161 - 2169 (2007/10/03)
A number of model compounds resembling the fundamental bonding patterns of residual kraft lignin, including a series of stilbenes, were incubated with laccase from Trametes versicolor in the presence and absence of delignification 'mediators' ABTS and HBT. The condensed kraft lignin model compounds seem to undergo initial degradation by laccase mainly via benzylic oxidation, demethylation and hydroxylation reactions. Phenolic 5-5', diphenylmethane and α-5 lignin models were found to be degraded mainly via side-chain oxidation reactions. Among the models studied, a phenolic stilbene was found to be the most reactive, yielding several products showing side-chain oxidation/transposition, demethoxylation and hydroxylation reactions. Non-phenolic 5-5', diphenylmethane and stilbene model compounds were found unreactive even in the presence of the laccase-mediator system. Copyright (C) 1997 Elsevier Science Ltd.
Synthetic entry to dibenzo[b,f]oxinin and dibenzo[b,f] azonine derivatives through a dibenzo[a,e]cycloocten-5-one
Elliott, I. Wesley,Sloan, Milton J.,Tate, Earl
, p. 8063 - 8072 (2007/10/03)
2,3,8,9-Tetramethoxy-5,6,11,12-tetrahydrodibenzo [a,e]cycloocten-5-one (2) was transformed by Baeyer-Villiger oxidation to the substituted 6- oxodibenzo[b,f]oxinin 6. One-pot Beckmann or Schmidt rearrangements of 2 afforded the 6-oxodibenzo[b,f]-azonine 8
Coralyne and related compounds as mammalian topoisomerase I and topoisomerase II poisons
Makhey, Darshan,Gatto, Barbara,Yu, Chiang,Liu, Angela,Liu, Leroy F.,LaVoie, Edmond J.
, p. 781 - 791 (2007/10/03)
DNA topoisomerases are nuclear enzymes responsible for modifying the topological state of DNA. The development of agents capable of poisoning topoisomerases has proved to be an attractive approach in the search for novel cancer chemotherapeutics. Coralyne, an antileukemic alkaloid, has appreciable structural similarity to the potent topoisomerase I and II poison, nitidine. Analogues of coralyne were synthesized and evaluated for their activity as topoisomerase I and topoisomerase II poisons. These analogues were also evaluated for cytotoxicity in the human lymphoblast cell line, RPMI 8402, and its camptothecin-resistant variant, CPT-K5. The pharmacological activity of these analogues exhibited a strong dependence on the substitution pattern and the nature of substituents. Several 1- benzylisoquinolines and 3-phenylisoquinolines were also synthesized. These compounds, which incorporate only a portion of the ring structure of coralyne, were evaluated as topoisomerase poisons and for cytotoxicity. These structure-activity studies indicate that the structural rigidity associated with the coralyne ring system may be critical for pharmacological activity. The presence of a 3,4-methylenedioxy substituent on these coralyne analogues was generally associated with enhanced activity as a topoisomerase poison. 5,6-Dihydro-3,4-methylenedioxy-10,11-dimethoxydibenzo[a,g]quinolizinium chloride was the most potent topoisomerase I poison among the coralyne analogues evaluated, having similar activity to camptothecin. This analogues also possessed exceptional potency as a topoisomerase II poison. Despite the pronounced activity of several of these coralyne derivatives as topoisomerase I poisons, mine of these compounds had cytotoxic activity similar to camptothecin. Possible differences in cellular absorption between these coralyne analogs, which possess a quaternary ammonium group, and camptothecin may be responsible for the differences observed in their relative cytotoxicity.
Sterically Hindered 1,4-Methylenebenzoquinones in the Synthesis of Six-Membered N-, O-, S-, and Se-Heterocycles
Komissarov, V. N.,Ukhin, L. Yu.,Vetoshkina, L. V.,Dupin, A. M.,Erin, A. N.
, p. 700 - 706 (2007/10/03)
In the presence of acids or bases or on heating 2,6-di-tert-butyl-4-(4,5-dimethoxy-2-phenacylbenzylidene)-2,5-cyclohexadien-1-ones are converted into isochromenes; treatment with hydroxylamine yields isoquinoline derivatives possessing high antioxidant activity.Reactions of these methylenebenzoquinones with elemental sulfur and selenium result in formation of 1,2-dihydro-2-thia(selena)naphthalene 2-oxides.
UNSYMMETRICALLY SUBSTITUTED DEOXYBENZOINS: AN IMPROVED PREPARATIVE ROUTE
Badia, D.,Dominguez, E.,Galarza, J.,Lete, E.,Marigorta, E. Martinez de,Villa, M. J.
, p. 77 - 82 (2007/10/02)
A regioselective synthesis of unsymmetrically substituted deoxybenzoins via α-aminonitriles, establishing the advantage of the use of N,N-dimethylaminonitriles over the corresponding N,N-diethylamino derivatives, is reported.
Influence of Alkoxyalkyl Substituents in the Regioselective Lithiation of the Benzene Ring
Napolitano, Elio,Giannone, Enrico,Fiaschi, Rita,Marsili, Antonio
, p. 3653 - 3657 (2007/10/02)
The concomitant presence of an alkoxyalkyl group (α-alkoxyalkyl, α- or β-dialkoxyalkyl) and of an alkoxy group in the relative positions 1 and 3 in a benzene ring generally permits an easy lithiation of position 2 by proton-metal exchange with n-butyllithium; the only aromatic compound tested, bearing a β-alkoxyalkyl group, gave, however, extensive decomposition in the metalation step.Reaction of the metalated species with an electrophile (such as carbon dioxide or ethyl chloroformate) leads to the corresponding substituted products in good to excellent yields.The following transformations are described: 3,4-dimethoxybenzyl α-ethoxyethyl ether (1) into 6,7-dimethoxyphthalide (15); 3,4-(methylenedioxy)benzyl α-ethoxyethyl ether (2) into 6,7-(methylenedioxy)phthalide (16); 3,4-dimethoxybenzyl methyl ether (3) into ethyl 2-(methoxymethyl)-5,6-dimethoxybenzoate (18) and into ethyl 2-(chloromethyl)-5,6-dimethoxybenzoate (20); 3,4-(methylenedioxy)benzyl methyl ether (4) into ethyl 2-(methoxymethyl)-5,6-(methylenedioxy)benzoate (19) and into ethyl 2-(chloromethyl)-5,6-(methylenedioxy)benzoate (21); 3,4-dimethoxybenzaldehyde dimethyl acetal (5) into 5,6-dimethoxyphthalaldehydic acid (22); 3,4-(methylenedioxy)benzaldehyde dimethyl acetal (6) into 5,6-(methylenedioxy)phthalaldehydic acid (23); (3,4-dimethoxyphenyl)acetaldehyde dimethyl acetal (7) into ethyl 2-(2,2-dimethoxyethyl)-5,6-dimethoxybenzoate (25); 3,4,4'-trimethoxydeoxybenzoin ethylene acetal (10) into 2-(ethoxycarbonyl)-3,4,4'-trimethoxydeoxybenzoin (26); 4,3',4'-trimethoxydeoxybenzoin ethylene acetal (11) into 2'-(ethoxycarbonyl)-4,3',4'-trimethoxydeoxybenzoin (27); 3,4,3',4'-tetramethoxydeoxybenzoin ethylene acetal (12) into a mixture of 3-(3,4-dimethoxybenzylidene)-6,7-dimethoxyphthalide (28) and 3-(3,4-dimethoxyphenyl)-7,8-dimethoxyisocoumarin (29).The dioxole ring of methylenedioxy-substituted benzenes is sometimes unstable under these metalation conditions, and partial decomposition usually causes the yields to be lower than those in the case of the corresponding methoxy-substituted benzenes.Many of the products listed above, which have been already prepared by other methods, are more conveniently obtained by the present approach.
