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Search for "hydroxylation" in Full Text gives 114 result(s) in Beilstein Journal of Organic Chemistry.

Alkylation of lithiated dimethyl tartrate acetonide with unactivated alkyl halides and application to an asymmetric synthesis of the 2,8-dioxabicyclo[3.2.1]octane core of squalestatins/zaragozic acids

  • Herman O. Sintim,
  • Hamad H. Al Mamari,
  • Hasanain A. A. Almohseni,
  • Younes Fegheh-Hassanpour and
  • David M. Hodgson

Beilstein J. Org. Chem. 2019, 15, 1194–1202, doi:10.3762/bjoc.15.116

Graphical Abstract
  • hydroxylation temperature, then a reduced yield of 19b was observed (53%). Indirect hydroxylation of the propylated tartrate enolate was also attempted using CBr4 (at −78 °C) as a more readily available/convenient electrophile, which also gave the hydroxy acetonide 19b presumably by way of hydrolysis on work-up
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Published 31 May 2019

Easy, efficient and versatile one-pot synthesis of Janus-type-substituted fullerenols

  • Marius Kunkel and
  • Sebastian Polarz

Beilstein J. Org. Chem. 2019, 15, 901–905, doi:10.3762/bjoc.15.87

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  • fullerenes with solubility in water. Thus, one important class of fullerene derivatives are the hydroxylated and polyhydroxylated compounds, so called fullerenols (C60(OH)n) [14]. The degree of hydroxylation and with that the solubility of these compounds can be tuned by using different synthetic approaches
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Letter
Published 12 Apr 2019

Selective benzylic C–H monooxygenation mediated by iodine oxides

  • Kelsey B. LaMartina,
  • Haley K. Kuck,
  • Linda S. Oglesbee,
  • Asma Al-Odaini and
  • Nicholas C. Boaz

Beilstein J. Org. Chem. 2019, 15, 602–609, doi:10.3762/bjoc.15.55

Graphical Abstract
  • catalytic NHPI and iodic acid mediated the hydroxylation or amidation of tertiary C–H bonds using either wet nitromethane or dry acetonitrile, respectively [54][55]. The substrate scope of the developed benzylic C–H monooxygenation reaction was examined via the oxidation of substrates containing benzylic C
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Published 05 Mar 2019

Synthesis of nonracemic hydroxyglutamic acids

  • Dorota G. Piotrowska,
  • Iwona E. Głowacka,
  • Andrzej E. Wróblewski and
  • Liwia Lubowiecka

Beilstein J. Org. Chem. 2019, 15, 236–255, doi:10.3762/bjoc.15.22

Graphical Abstract
  • electrophilic hydroxylation at C4 When the lithium enolate of dimethyl N-Cbz-L-glutamate 63 was treated with Davis oxaziridine, an inseparable 9:1 mixture of diastereoisomers was formed with (2S,4S)-64 predominating (Scheme 16) [74]. For sodium and potassium enolates diastereoselectivity of the hydroxylation
  • [86][87][88] or a Diels–Alder reaction using acylnitroso compounds [89]. However, when compared with these multistep approaches hydroxylation of pyroglutamic acid derivatives seems to be the simplest option. Treatment of the lithium enolate of benzyl N-Boc-pyroglutamate (S)-86 with Davis oxaziridine
  • produced (2S,4R)-87 (Scheme 22) [90][91][92]. HPLC investigation of the reaction mixture showed that (2S,4S)-87 was not formed [90]. Stereospecific hydroxylation occurred on the opposite side to the benzyloxycarbonyl group, i.e., only re-face of the enolate was attacked for steric reasons. It is worth
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Published 25 Jan 2019

DABCO- and DBU-promoted one-pot reaction of N-sulfonyl ketimines with Morita–Baylis–Hillman carbonates: a sequential approach to (2-hydroxyaryl)nicotinate derivatives

  • Soumitra Guin,
  • Raman Gupta,
  • Debashis Majee and
  • Sampak Samanta

Beilstein J. Org. Chem. 2018, 14, 2771–2778, doi:10.3762/bjoc.14.254

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  • the synthesis of (2-hydroxyaryl)pyridines from 2-arylpyridines via a direct C–H hydroxylation on the aryl ring using several expensive transition metal salts (e.g., Pd(II) [60][61][62][63], Rh(III) [64][65], Ru(II) [66]) as catalysts (Scheme 1a). However, the above methods have several drawbacks such
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Published 02 Nov 2018

Targeting the Pseudomonas quinolone signal quorum sensing system for the discovery of novel anti-infective pathoblockers

  • Christian Schütz and
  • Martin Empting

Beilstein J. Org. Chem. 2018, 14, 2627–2645, doi:10.3762/bjoc.14.241

Graphical Abstract
  • , PQS is produced through hydroxylation of position 3 by the NADH-dependent flavin mono-oxygenase PqsH [32]. This biosynthetic cascade is also responsible for the generation of the pqs-related metabolites DHQ, 2-AA, and HQNO as well as other AQs having different lengths of the alkyl chain [29][30
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Published 15 Oct 2018

The enzymes of microbial nicotine metabolism

  • Paul F. Fitzpatrick

Beilstein J. Org. Chem. 2018, 14, 2295–2307, doi:10.3762/bjoc.14.204

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  • deal of interest in identifying bacteria capable of degrading it. A number of microbial pathways have been identified for nicotine degradation. The first and best-understood is the pyridine pathway, best characterized for Arthrobacter nicotinovorans, in which the first reaction is hydroxylation of the
  • . JS614; in this case the genes are chromosomal [6]. As shown in Scheme 1, the pathway begins with hydroxylation of the pyridyl ring of nicotine by the enzyme nicotine dehydrogenase to yield 6-hydroxynicotine [7]. Based on the gene sequence, this enzyme was identified as a member of the family of
  • the enzyme. While the dominant form of nicotine found in tobacco is (S)-nicotine, the (R)-stereoisomer is also found at detectable levels [22]. Nicotine dehydrogenase is reported not to be stereospecific, in that it can catalyze the hydroxylation of (R)-nicotine to (R)-6-hydroxynicotine; thus, this
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Published 31 Aug 2018

Cobalt-catalyzed peri-selective alkoxylation of 1-naphthylamine derivatives

  • Jiao-Na Han,
  • Cong Du,
  • Xinju Zhu,
  • Zheng-Long Wang,
  • Yue Zhu,
  • Zhao-Yang Chu,
  • Jun-Long Niu and
  • Mao-Ping Song

Beilstein J. Org. Chem. 2018, 14, 2090–2097, doi:10.3762/bjoc.14.183

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  • –C or C–heteroatom bonds has attracted more attention [8][9][10][11][12][13]. In particular, the formation of C–O bonds is widely used in the syntheses of pharmaceuticals and functional materials [14][15][16][17]. The direct hydroxylation [18][19] and acetoxylation [20][21][22] have been developed
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Letter
Published 09 Aug 2018

A survey of chiral hypervalent iodine reagents in asymmetric synthesis

  • Soumen Ghosh,
  • Suman Pradhan and
  • Indranil Chatterjee

Beilstein J. Org. Chem. 2018, 14, 1244–1262, doi:10.3762/bjoc.14.107

Graphical Abstract
  • used by Quideau et al. for the α-hydroxylation of phenolic derivatives via oxygenative dearomatization. Quideau et al. showed that iodobiarene 38 was oxidized in situ by m-CPBA to generate the I(III) reagent which is responsible for the hydroxylative naphthol dearomatization affording the product in
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Published 30 May 2018

An overview of recent advances in duplex DNA recognition by small molecules

  • Sayantan Bhaduri,
  • Nihar Ranjan and
  • Dev P. Arya

Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93

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Published 16 May 2018

Hypervalent iodine(III)-mediated decarboxylative acetoxylation at tertiary and benzylic carbon centers

  • Kensuke Kiyokawa,
  • Daichi Okumatsu and
  • Satoshi Minakata

Beilstein J. Org. Chem. 2018, 14, 1046–1050, doi:10.3762/bjoc.14.92

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  • amounts of heavy metal oxidants under high-temperature conditions [14][15]. Because these oxidants are typically highly toxic, their use has remained limited in organic synthesis. Barton et al. reported on the development of a practical method for the decarboxylative hydroxylation using thiohydroxamate
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Published 15 May 2018

Anodic oxidation of bisamides from diaminoalkanes by constant current electrolysis

  • Tatiana Golub and
  • James Y. Becker

Beilstein J. Org. Chem. 2018, 14, 861–868, doi:10.3762/bjoc.14.72

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  • : anodic oxidation; bisamides; constant current electrolysis; methoxylation; Introduction It is well known that the anodic oxidation of amides involving a hydrogen atom at the α-position to the N atom could undergo alkoxylation, carboxylation and hydroxylation at this position [1][2][3][4][5] (Scheme 1
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Published 16 Apr 2018

Latest development in the synthesis of ursodeoxycholic acid (UDCA): a critical review

  • Fabio Tonin and
  • Isabel W. C. E. Arends

Beilstein J. Org. Chem. 2018, 14, 470–483, doi:10.3762/bjoc.14.33

Graphical Abstract
  • reduction) and the specific hydroxylation and dehydroxylation of suitable positions in the steroid rings. In this minireview, we critically analyze the state of the art of the production of UDCA by several chemical, chemoenzymatic and enzymatic routes reported, highlighting the bottlenecks of each
  • ] reported that a fungal strain (Fusarium equiseti M41) was able to introduce a 7β-hydroxy group into LCA by hydroxylation forming UDCA directly. Later, many other microorganisms with a 7β-hydroxylating activity were discovered in strains of actinobacteria and filamentous fungi [96][97]. The key-enzyme in
  • that pathway is a P450-like enzyme that catalyses the specific and irreversible 7β-hydroxylation. On this topic, a recent work by Kollerov et al. [98] describes several DCA modifying filamentous fungi strains (mostly ascomycetes and zygomycetes): the highest 7β-hydroxylase activity level was found in
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Published 20 Feb 2018

Photocatalytic formation of carbon–sulfur bonds

  • Alexander Wimmer and
  • Burkhard König

Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4

Graphical Abstract
  • ]. The reaction is catalyzed by [fac-Ir(ppy)3] under visible-light irradiation and proceeds via an oxidative quenching cycle, generating reactive sulfonyl radicals from sulfonyl chlorides. The key to β-hydroxylation is the use of a mixture of acetonitrile and water (5:1) as solvent. They confirmed by 18O
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Published 05 Jan 2018

Aminosugar-based immunomodulator lipid A: synthetic approaches

  • Alla Zamyatina

Beilstein J. Org. Chem. 2018, 14, 25–53, doi:10.3762/bjoc.14.3

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Published 04 Jan 2018

Chiral phase-transfer catalysis in the asymmetric α-heterofunctionalization of prochiral nucleophiles

  • Johannes Schörgenhumer,
  • Maximilian Tiffner and
  • Mario Waser

Beilstein J. Org. Chem. 2017, 13, 1753–1769, doi:10.3762/bjoc.13.170

Graphical Abstract
  • most important field of application of this catalytic principle. Based on several highly spectacular recent reports, we thus wish to discuss some of the most important achievements in this field within the context of this review. Keywords: amination; chlorination; fluorination; hydroxylation
  • ]. Besides those methods that make use of already α-functionalized carbonyl compounds, the direct stereoselective α-oxygenation or α-hydroxylation of simple prochiral nucleophiles with either oxygen as such, or an electrophilic oxygen species became by far the most important and most thoroughly investigated
  • -transfer catalysis [110]. In this seminal investigation, they succeeded in carrying out the direct α-hydroxylation of simple ketones 15 by using O2 in combination with triethylphosphite, which leads to the in situ formation of a reactive hydroperoxide derivative. When using the easily accessible cinchona
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Published 22 Aug 2017

Oxidative dehydrogenation of C–C and C–N bonds: A convenient approach to access diverse (dihydro)heteroaromatic compounds

  • Santanu Hati,
  • Ulrike Holzgrabe and
  • Subhabrata Sen

Beilstein J. Org. Chem. 2017, 13, 1670–1692, doi:10.3762/bjoc.13.162

Graphical Abstract
  • catalytic amount of potassium iodide (0.2 mmol) and 0.25 mL of tert-butylhydroperoxide (TBHP, 70 wt %) in water (4 equiv) to afford the dihydroisoquinazoline 34a, which got oxidized to the quinazolium intermediate 34b. Hydroxylation of 34b afforded 34c, which was further reacted with nitroalkanes at 50 °C
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Published 15 Aug 2017

The chemistry and biology of mycolactones

  • Matthias Gehringer and
  • Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

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Published 11 Aug 2017

Opportunities and challenges for the sustainable production of structurally complex diterpenoids in recombinant microbial systems

  • Katarina Kemper,
  • Max Hirte,
  • Markus Reinbold,
  • Monika Fuchs and
  • Thomas Brück

Beilstein J. Org. Chem. 2017, 13, 845–854, doi:10.3762/bjoc.13.85

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  • diversity of terpene products is obtained by precise modulation of cyclization and rearrangement steps performed by terpene cyclase enzymes [31], initial functional groups are introduced by hydroxylation of the carbon backbone with highly specific P450 monooxygenases [42][43][44]. At present, terpene
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Published 08 May 2017

Transition-metal-catalyzed synthesis of phenols and aryl thiols

  • Yajun Liu,
  • Shasha Liu and
  • Yan Xiao

Beilstein J. Org. Chem. 2017, 13, 589–611, doi:10.3762/bjoc.13.58

Graphical Abstract
  • other hand, the C–H hydroxylation, either with heteroatom-containing directing groups or without directing groups, has provided various methods for the synthesis of phenols. Compared with traditional methods, the transition-metal-catalyzed phenol synthesis has several advantages: broad substrate scope
  • for the synthesis of phenols. In the beginning, palladium catalysts have attracted much attention due to their high conversion efficiency, and later copper catalysts, which are cheaper and more stable, have been extensively studied in this field. 1.1.1 Palladium-catalyzed hydroxylation of aryl halides
  • as the base and succeeded in the hydroxylation of aryl halides [22]. They chose tri-tert-butylphosphine as the ligand in their reaction system and obtained the phenols from aryl halides, suggesting a great influence of the ligand on the reaction performance (Scheme 2). However, their protocol was
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Published 23 Mar 2017

Biosynthetic origin of butyrolactol A, an antifungal polyketide produced by a marine-derived Streptomyces

  • Enjuro Harunari,
  • Hisayuki Komaki and
  • Yasuhiro Igarashi

Beilstein J. Org. Chem. 2017, 13, 441–450, doi:10.3762/bjoc.13.47

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  • alternative alignment of the methylene and the oxygenated carbons. Meanwhile, a 1,2-diol in polyketides is known to be formed by hydroxylation of methylene carbons as seen in the biosynthesis of erythromycin or amphotericin B [17][18]. The contiguously hydroxylated carbon chain of 1 is quite unusual as a
  • to C-4) and the pentaol (C-5 to C-9) moieties (Figure 3), suggesting that the contiguous polyol system is not formed by methylene hydroxylation. Another possible pathway for 1,2-diol formation is the incorporation of hydroxymalonyl-ACP from a glycolytic intermediate for chain elongation [23]. To
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Published 08 Mar 2017

Useful access to enantiomerically pure protected inositols from carbohydrates: the aldohexos-5-uloses route

  • Felicia D’Andrea,
  • Giorgio Catelani,
  • Lorenzo Guazzelli and
  • Venerando Pistarà

Beilstein J. Org. Chem. 2016, 12, 2343–2350, doi:10.3762/bjoc.12.227

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  • [8][9][10][11][12][13]; 2) elaboration of the six carbon atom skeleton of either a) tetrahydroxycyclohexene derivatives [14][15] (synthetic or natural conduritols) through stereoselective cis-hydroxylation or epoxidation–hydrolysis of the double bond or b) benzene [16][17] or halo-benzenes [18][19
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Published 08 Nov 2016

Rearrangements of organic peroxides and related processes

  • Ivan A. Yaremenko,
  • Vera A. Vil’,
  • Dmitry V. Demchuk and
  • Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

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Published 03 Aug 2016

Biosynthesis of oxygen and nitrogen-containing heterocycles in polyketides

  • Franziska Hemmerling and
  • Frank Hahn

Beilstein J. Org. Chem. 2016, 12, 1512–1550, doi:10.3762/bjoc.12.148

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  • consumption of hydrogen peroxide. It has been shown that the AS is substrate tolerant and accepts different hydroxylation patterns as well as glycosylations on the chalcone A and B rings [154]. However, the oxidative half-reaction only occurs with chalcones and not with other aryl substrates like L-tyrosine
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Published 20 Jul 2016

Muraymycin nucleoside-peptide antibiotics: uridine-derived natural products as lead structures for the development of novel antibacterial agents

  • Daniel Wiegmann,
  • Stefan Koppermann,
  • Marius Wirth,
  • Giuliana Niro,
  • Kristin Leyerer and
  • Christian Ducho

Beilstein J. Org. Chem. 2016, 12, 769–795, doi:10.3762/bjoc.12.77

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  • synthetase (NRPS) system appears to be responsible for the assembly of the urea tripeptide building block 105. However, the non-proteinogenic amino acids need to be formed first. It has been proposed that L-arginine (106) undergoes 3-hydroxylation (giving 3-hydroxy-L-arginine (107)) and subsequent ring
  • thioester 109 is proposed to be converted into the urea dipeptide motif with valine derivative 110 and possibly hydrogen carbonate as a C1-building block for urea formation, thus furnishing 111. The 3-hydroxy-L-leucine moiety might be obtained by stereoselective enzymatic β-hydroxylation of thioester
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Published 22 Apr 2016
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