- Indoloquinones, part 7. Total synthesis of the potent lipid peroxidation inhibitor carbazoquinocin C by an intramolecular palladium-catalyzed oxidative coupling of an anilino-1,4-benzoquinone
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A highly efficient total synthesis of the potent lipid peroxidation inhibitor carbazoquinocin C is presented. The key-step is a palladium(II)-catalyzed oxidative cyclization of an anilino-1,4-benzoquinone to a carbazole-1,4-quinone which proceeds in up to 91% yield. Using this approach the natural product is obtained in four steps and 39% overall yield starting from aniline.
- Kn?lker, Hans-Joachim,Fr?hner, Wolfgang,Reddy, Kethiri R.
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Read Online
- TREATMENT OR PREVENTION OF LEUKAEMIA
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The present invention provides compounds for use in the treatment or prevention of leukaemia which are based on a 2-amino-[1,1']-bipbenyl or corresponding carbazole scaffold, in particular, it provides the following compounds of formula (I), their stereoi
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Page/Page column 15-16
(2021/04/23)
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- Hit to Leads with Cytotoxic Effect in Leukemic Cells: Total Synthesis Intermediates as a Molecule Treasure Chest
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A previously designed and developed 12-step total synthesis that includes [1,1′-biphenyl]-2-amine and carbazole intermediates and that ultimately produces the carbazole alkaloid carbazomycin G was exploited as a screening compound library with the goal of
- Bj?rsvik, Hans-René,Gjertsen, Bj?rn Tore,Elumalai, Vijayaragavan
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p. 862 - 870
(2020/05/05)
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- Carbazomycin G: Method Development and Total Synthesis
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A novel total synthesis leading to the carbazole alkaloid carbazomycin G was designed and developed. The outlined synthetic route is composed of twelve synthetic steps including the transformations of the initial simple substrate and intermediates. To rea
- Elumalai, Vijayaragavan,Gambarotti, Cristian,Bj?rsvik, Hans-René
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p. 1984 - 1992
(2018/05/15)
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- Synthesis of the ABH rings of ecteinascidin 597 using a connective Pummerer-type cyclisation
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A connective Pummerer-type cyclisation involving a cysteine derivative and an N-benzyl glyoxamide 3 has been applied in an asymmetric synthesis of the protected ABH rings 2 of the antitumour and antimicrobial natural product ecteinascidin 597.
- Smith, Laura H. S.,Nguyen, Trung Thanh,Sneddon, Helen F.,Procter, David J.
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supporting information; experimental part
p. 10821 - 10823
(2011/11/05)
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- New Drug Delivery System for Crossing the Blood Brain Barrier
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New ubiquinol analogs are disclosed, as well as methods of using these compounds to deliver drug moieties to the body.
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Page/Page column 25
(2008/06/13)
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- Efficient and green telescoped process to 2-methoxy-3-methyl-[1,4] benzoquinone
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A telescoped process for the preparation of 2-methoxy-3-methyl-[1,4] benzoquinone is disclosed. When this novel process is compared to the prevailing method that utilizes Na2Cr2O7 as the oxidant, the novel process represen
- Rodriguez Gonzalez, Raquel,Gambarotti, Cristian,Liguori, Lucia,Bjorsvik, Hans-Rene
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p. 1703 - 1706
(2007/10/03)
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- Synthesis of methoxy-substituted phenols by peracid oxidation of the aromatic ring
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A novel benign protocol for the preparation of hydroxy-methoxybenzene derivatives is disclosed. By utilizing this protocol, activated aromatic compounds such as l,3-dimethoxy-2-methyl-benzene and 1-(2,6-dimethoxyphenyl) ethanone are smoothly converted to the corresponding monohydroxylated compound. The reaction can be considered to be a normal aromatic electrophilic substitution reaction, and the regioselectivity for the reaction thus follows the similar rules as for electrophilic substitutions. The protocol is composed by benign reagents, namely, hydogenperoxide, acetic acid, and p-toluene sulfonic acid, which lead to the production of ethaneperoxoic acid in situ. The ethaneperoxoic acid operates as the hydroxylating reagent. The hydroxylation reaction is completed within a short period and requires moreover only mild experimental conditions, which make this novel protocol a green, cheap, and rapid process leading to hydroxy-methoxybenzene derivatives. The proposed reaction mechanism is supported by density functional theory and NMR spectroscopy experiments. The mechanism is constituted by two discrete steps: (a) addition of OH+ to the most nucleophilic carbon atom of the aromatic ring, which is the rate-determining step, and (b) the loss of the proton from the aromatic ring.
- Bjorsvik, Hans-Rene,Occhipinti, Giovanni,Gambarotti, Cristian,Cerasino, Leonardo,Jensen, Vidar R.
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p. 7290 - 7296
(2007/10/03)
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- Access to orthogonal protected phenols - Synthesis of a silylated quinol
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Herein we describe the synthesis of t-butyldimethylsilyl protected quinol (9), using an oxidation/reduction sequence to create the desired orthogonality. The title compound acts as a synthetic equivalent for a quinone, required in the total synthesis of E
- Siddiqi, Shahzad A.,Heckrodt, Thilo J.
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p. 328 - 331
(2007/10/03)
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- Synthesis of a Diels-Alder precursor for the Elisabethin A skeleton
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A synthesis of a precursor 2 for the Elisabethin A skeleton is reported. Containing a masked quinone and a (E,Z)-diene sub-unit, it has the required elements for the envisaged intramolecular Diels-Alder reaction to form the tricyclic system of Elisabethin A. Starting from methylresorcinol, the sequence involves the preparation of an arylacetic acid, which was α-alkylated by a chiral building block. Subsequent HWE reaction and cis-selective Wittig olefination furnished the diene with the desired geometry.
- Heckrodt, Thilo J.,Mulzer, Johann
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p. 1857 - 1866
(2007/10/03)
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- Transition metal complexes in organic synthesis, Part 38. First total synthesis of carbazomycin G and H
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The first total synthesis of the carbazole quinol alkaloids carbazomycin G and H has been achieved by a highly convergent synthesis using an iron-mediated construction of the carbazole nucleus as key-step.
- Knoelker, Hans-Joachim,Froehner, Wolfgang
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p. 4051 - 4054
(2007/10/03)
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- An Investigation into the Unusual Formation of an Isocoumarin by Acetylation of 2,3,6-Trimethoxytoluene with (E)-2-Methylbut-2-enoic Acid and Trifluoroacetic Anhydride
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Prolonged reaction of 2,3,6-trimethoxytoluene with an excess of premixed (E)-2-methylbut-2-enoic acid and trifluoroacetic anhydride in air affords 5,6,8-trimethoxy-3,4,7-trimethylisocoumarin 11 in 66percent yield as the sole product isolated, the structur
- Botha, Marc E.,Giles, Robin G. F.,Moorhoff, Cornelis M.,Engelhardt, Lutz M.,White, Allan H.,et al.
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- SYNTHETIC APPROCHES TOWARD MITOMYCINS. I. STEREOSELECTIVE SYNTHESIS OF A TETRACYCLIC INTERMEDIATE.
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A highly efficient synthesis of a tetracyclic intermediate 5 to the antitumor antibiotics AX-2 4, mitimycin A 2, and C 1 is described.
- Fukuyama, Tohru,Yang, Lihu
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p. 6299 - 6300
(2007/10/02)
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