Copper catalysis with redox-active ligands

• Agnideep Das,
• Yufeng Ren,
• Cheriehan Hessin and
• Marine Desage-El Murr

Beilstein J. Org. Chem. 2020, 16, 858–870, doi:10.3762/bjoc.16.77

• 6D, in which the H-atom is transferred from the secondary benzylic sp3 carbon to the redox-active ligand, acting as a cooperative H-atom acceptor. Following a proton-coupled electron transfer (PCET) to generate 6E, the oxidized product (benzaldehyde) is released and final elimination of H2O2

A systematic review on silica-, carbon-, and magnetic materials-supported copper species as efficient heterogeneous nanocatalysts in “click” reactions

• Pezhman Shiri and
• Jasem Aboonajmi

Beilstein J. Org. Chem. 2020, 16, 551–586, doi:10.3762/bjoc.16.52

• for 2 h. The mixture was also diluted with hot water and then, H2O2 was added to adjust the pH value and to terminate the reaction. In the next step, the resulting mixture was washed with distilled water, and the pure graphene oxide powder was gathered by centrifugation and dried. The GO was dispersed

A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions

• Munmun Ghosh,
• Valmik S. Shinde and
• Magnus Rueping

Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264

• chloroperoxidase catalyst. H2O2 generated in situ from the cathodic reduction of oxygen was proposed to be responsible for the enzyme-mediated thiol ether oxidation (Scheme 47) [82]. Vitamin B12-dependent enzymes are an exciting representative in the family of chiral inductors for electroorganic chemistry. These

Chiral terpene auxiliaries V: Synthesis of new chiral γ-hydroxyphosphine oxides derived from α-pinene

• Anna Kmieciak and
• Marek P. Krzemiński

Beilstein J. Org. Chem. 2019, 15, 2493–2499, doi:10.3762/bjoc.15.242

• (H2O2/NaOH) proceeded with the low yield (32%). Application of m-chloroperbenzoic acid (mCPBA) as an oxidant, similarly to Knochels findings [19], gave the higher yield (56%) of (((1R,2R,3R,4R,5R)-4-hydroxypinan-3-yl)methyl)diphenylphosphine oxide (22). Next, phosphine oxide 22 was reduced to the

Synthesis of 1-azaspiro[4.4]nonan-1-oxyls via intramolecular 1,3-dipolar cycloaddition

• Yulia V. Khoroshunova,
• Denis A. Morozov,
• Andrey I. Taratayko,
• Polina D. Gladkikh,
• Yuri I. Glazachev and
• Igor A. Kirilyuk

Beilstein J. Org. Chem. 2019, 15, 2036–2042, doi:10.3762/bjoc.15.200

• performed for reductive isoxazolidine ring opening [15][16] producing aminoalcohols 9a–c in 85–95% yields (Scheme 2). We have previously reported that oxidation of secondary amines with a spiro(2-hydroxymethyl)cyclopentane moiety at the α-carbon with the H2O2/WO42− system is ineffective whereas conversion

A review of the total syntheses of triptolide

• Xiang Zhang,
• Zaozao Xiao and
• Hongtao Xu

Beilstein J. Org. Chem. 2019, 15, 1984–1995, doi:10.3762/bjoc.15.194

• the desired stereochemistry of the C-7 benzylic hydroxy group. Compound 46 was converted to triptonide 2 by Alder periodate reaction (NaIO4, 74%), and a sequencing m-CPBA epoxidation and basic hydrogen peroxide oxidation (H2O2/OH−) procedure (two steps, 28%). Finally, sodium borohydride reduction of 2

• epoxydienone via the methodology developed by Alder et al., which was treated without purification with basic H2O2 to yield diepoxide 67, along with its 12,13-β-isomer. The mixture was immediately oxidized with 3,5-(NO2)2C6H3CO3H and Na2HPO4 to give triptonide (2, 15% from 67), and reduction of triptonide via

Application of chiral 2-isoxazoline for the synthesis of syn-1,3-diol analogs

• Juanjuan Feng,
• Tianyu Li,
• Jiaxin Zhang and
• Peng Jiao

Beilstein J. Org. Chem. 2019, 15, 1840–1847, doi:10.3762/bjoc.15.179

• reduction [4][5][6][7][8][9][10][11] of 7 using Et2BOMe and NaBH4 at −78 °C gave stable ethylboronate 8 in 96% yield. Several ethylboronate compounds have been reported [9][10][11][56][57][58][59][60][61][62]. From 8 to 9, no H2O2 treatment was necessary. Rotary evaporation of 8 with CH3OH at ca. 40 °C

Metal-free mechanochemical oxidations in Ertalyte^® jars

• Andrea Porcheddu,
• Francesco Delogu,
• Lidia De Luca,
• Claudia Fattuoni and
• Evelina Colacino

Beilstein J. Org. Chem. 2019, 15, 1786–1794, doi:10.3762/bjoc.15.172

• process [55]. Also, Oxone® and NH2CONH2·H2O2 appeared to fail in the oxidation of 3-phenyl-1-propanol (1a) to the corresponding aldehyde. Subsequently, we turned our attention to sodium hypochlorite (NaOCl), an inexpensive and widely used oxidizing reagent also applied as a disinfectant and household

N-(1-Phenylethyl)aziridine-2-carboxylate esters in the synthesis of biologically relevant compounds

• Iwona E. Głowacka,
• Aleksandra Trocha,
• Andrzej E. Wróblewski and
• Dorota G. Piotrowska

Beilstein J. Org. Chem. 2019, 15, 1722–1757, doi:10.3762/bjoc.15.168

Stereo- and regioselective hydroboration of 1-exo-methylene pyranoses: discovery of aryltriazolylmethyl C-galactopyranosides as selective galectin-1 inhibitors

• Alexander Dahlqvist,
• Axel Furevi,
• Niklas Warlin,
• Hakon Leffler and
• Ulf J. Nilsson

Beilstein J. Org. Chem. 2019, 15, 1046–1060, doi:10.3762/bjoc.15.102

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

• tetrabutylammonium hydroxide (0.5 mL of a 30% solution in H2O). The reactants for the polyhydroxylation are added, H2O2 (1.5 mL of a 30% solution) and NaOH (0.7 g). The mixture is heated to reflux until the chlorobenzene phase decolorizes. The reaction is completed after 2 h of reflux. The aqueous phase is separated

An efficient synthesis of the guaiane sesquiterpene (−)-isoguaiene by domino metathesis

• Yuzhou Wang,
• Ahmed F. Darweesh,
• Patrick Zimdars and
• Peter Metz

Beilstein J. Org. Chem. 2019, 15, 858–862, doi:10.3762/bjoc.15.83

• analysis for (−)-isoguaiene (1). Synthesis of 1 by relay metathesis of trienyne 3. a) HC(OMe)3, 4 mol % LiBF4, MeOH, reflux, 80%; b) (i) BH3·Me2S, THF, 0 °C to rt, (ii) 30% H2O2, 10% NaOH, 0 °C to rt, 97%; c) 5 mol % TPAP, NMO, CH2Cl2, rt, 97%; d) 13, THF, rt to reflux, 96%; e) 25 mol % TsOH, THF, H2O

An efficient and concise access to 2-amino-4H-benzothiopyran-4-one derivatives

• Peng Li,
• Yongqi Wu,
• Tingting Zhang,
• Chen Ma,
• Ziyun Lin,
• Gang Li and
• Haihong Huang

Beilstein J. Org. Chem. 2019, 15, 703–709, doi:10.3762/bjoc.15.65

• from 2’-chloroacetophenone as the starting material through treatment with carbon disulfide in the presence of sodium hydride [23], followed by alkylation using iodoethane according to the literature procedures [13][16][17][19]. The oxidation of 1 with 1.2 or 5 equiv of H2O2 yielded ethyl sulfoxide 2

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

• . Reagents and conditions: a) NaClO2, 30% H2O2, NaH2PO4, MeCN; b) ClCOOEt, NEt3, then CH2N2, ether; c) MeOH, PhCOOAg, NEt3; d) LiOH, THF/H2O; e) ClCOOBn, NEt3, DMAP; f) TFA, H2O; g) NaIO4, acetone/water; h) NaHCO3, THF/H2O; i) H2C=CHCH2Br, NaHCO3, DMF; j) H2, 10% Pd/C, MeOH/HCl. Synthesis of (4S)-4-hydroxy-L

• , ethanol/water. Synthesis of the orthogonally protected 4-hydroxyglutamic acid (2S,4S)-73. Reagents and conditions: a) toluene, 25 °C; b) LiOH, H2O2/THF; c) O-tert-butyl-N,N′-diisopropylisourea, CuCl; d) H2, 10% Pd/C, Boc2O, MeOH. Synthesis of (2S,4R)-4-acetyloxyglutamic acid as a component of a dipeptide

• protected serinal (R)-23. Reagents and conditions: a) Ph3P=CHCOOMe, benzene; b) Ac2O, NEt3, DMAP, CH2Cl2; c) 30% H2O2, PTSA, MgSO4, DME; d) K2CO3, MeOH; e) MeOH, 45 °C; f) Piv2O, NEt3, DMAP, CH2Cl2; g) PTSA, MeOH; h) CrO3, H5IO6, MeCN; i) 6 M HCl, reflux. Synthesis of (2S,3S,4S)-4 from O-benzyl-N-Boc-D

Unexpected loss of stereoselectivity in glycosylation reactions during the synthesis of chondroitin sulfate oligosaccharides

• Teresa Mena-Barragán,
• José L. de Paz and
• Pedro M. Nieto

Beilstein J. Org. Chem. 2019, 15, 137–144, doi:10.3762/bjoc.15.14

• assays, deprotection of dimer 6 and tetramer 14β were accomplished (Scheme 5). Compound 14α was also submitted to the deprotection sequence to obtain a non-natural α-containing oligosaccharide. Basic hydrolysis using H2O2/LiOH and then NaOH followed by selective N-acetylation in MeOH afforded CS

• , 25% (14α) + 33% (14β). Reagents and conditions: a) LiOH, H2O2, THF, −5 °C to rt, 24 h, then NaOH, MeOH, 72 h, then Ac2O, Et3N, MeOH, 2 h, 38% (15); 30% (16α); 73% (16β). Reagents and conditions: a) 2-propanol, TMSOTf, CH2Cl2, 0 °C, 30 min, 73%; b) NH2NH2·H2O, Py/AcOH, CH2Cl2, 1 h, 89%; c) 1, TMSOTf

Mn-mediated sequential three-component domino Knoevenagel/cyclization/Michael addition/oxidative cyclization reaction towards annulated imidazo[1,2-a]pyridines

• Olga A. Storozhenko,
• Alexey A. Festa,
• Delphine R. Bella Ndoutoume,
• Alexander V. Aksenov,
• Alexey V. Varlamov and
• Leonid G. Voskressensky

Beilstein J. Org. Chem. 2018, 14, 3078–3087, doi:10.3762/bjoc.14.287

• screening of the oxidants revealed, that the use of molecular iodine gave the desired product with 27% yield (Table 1, entry 4), while employment of NaOCl, NaIO4, MnO2, H2O2, or CuI/TBHP was not effective and led to the formation of complex mixtures (Table 1, entries 5–9), and use of CAN did not promote the

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

• as the requirement of high temperatures or use of strong oxidants (H2O2, oxone, K2S2O8, TBHP, PIDA, NHPI etc.) that are not much compatible with functionality, precluding late-stage functionalization. Moreover, the scope of substitution on the pyridine ring is limited which in turn hampers the

A general and atom-efficient continuous-flow approach to prepare amines, amides and imines via reactive N-chloramines

• Katherine E. Jolley,
• Michael R. Chapman and
• A. John Blacker

Beilstein J. Org. Chem. 2018, 14, 2220–2228, doi:10.3762/bjoc.14.196

• equivalents of aldehyde 17 led to 30% product formation (Table 3, entry 6). Notably, other oxidants such as H2O2 and NaOCl failed to produce any amide product. Likewise, attempts to couple morpholine in place of its N-chloro derivative reached only 19% conversion. Following the investigation of the batch

Design, synthesis and structure of novel G-2 melamine-based dendrimers incorporating 4-(n-octyloxy)aniline as a peripheral unit

• Cristina Morar,
• Pedro Lameiras,
• Attila Bende,
• Gabriel Katona,
• Emese Gál and
• Mircea Darabantu

Beilstein J. Org. Chem. 2018, 14, 1704–1722, doi:10.3762/bjoc.14.145

• comportment of G-1 piperazine dendron D-N

  NH being not entirely ruled out [68]. In line with this hypothesis, we recently described [35] the aptitude of the non-O-n-octylated analogue of G-2 dendrimer 4 (Scheme 3) to deprotonate Hemin completely (1:5 molar ratio), thus generating a new MOF for H2O2

Biocatalytic synthesis of the Green Note trans-2-hexenal in a continuous-flow microreactor

• Morten M. C. H. van Schie,
• Tiago Pedroso de Almeida,
• Gabriele Laudadio,
• Florian Tieves,
• Elena Fernández-Fueyo,
• Timothy Noël,
• Isabel W. C. E. Arends and
• Frank Hollmann

Beilstein J. Org. Chem. 2018, 14, 697–703, doi:10.3762/bjoc.14.58

• catalytic amounts only) causes additional costs. Therefore, we concentrated on alcohol oxidase-catalysed reaction schemes (Scheme 1B. Oxidases utilise O2 as terminal electron acceptor for the oxidation reaction yielding H2O2 as sole byproduct. The latter can be disproportionated easily by using catalase

• of trans-hex-2-enal. B: Envisioned aerobic oxidation using alcohol oxidases (AOx). H2O2 is formed as byproduct and dismutated by catalase into H2O and O2. Effect of variation of the gas-to-liquid ratio on the rate of the PeAAOx-catalysed aerobic oxidation of trans-hex-2-enol. Supporting Information

Fluorescent nucleobase analogues for base–base FRET in nucleic acids: synthesis, photophysics and applications

• Mattias Bood,
• Sangamesh Sarangamath,
• Moa S. Wranne,
• Morten Grøtli and
• L. Marcus Wilhelmsson

Beilstein J. Org. Chem. 2018, 14, 114–129, doi:10.3762/bjoc.14.7

• , where R = H, 7-MeO or 8-MeO [47]. a) H2NNH2 followed by H2O2, 20 h, 100 °C, 60–98%; b) PEt3, H2O, diglyme, then Na2CO3 and 5-bromouracil, rt to 120 °C, 2 h, 24–86%; c) HCl, butanol, 120 °C, 24–72 h, 27–86%; d) BSA (bis(trimethylsilyl)acetamide), Hoeffer´s α-chloro sugar, SnCl4, 0 °C to rt, 2 h, 12–41

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF₃SO₂Na

• Hélène Guyon,
• Hélène Chachignon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

• simple alkenes, sodium triflinate and diazonium salts. The CF3 radical was produced from CF3SO2Na by oxidation with H2O2 in the presence of silver nitrate. Then, CF3• was added to the terminal position of the alkene to give radical 26 that was trapped by the arenediazonium salt to form the radical cation

Syntheses, structures, and stabilities of aliphatic and aromatic fluorous iodine(I) and iodine(III) compounds: the role of iodine Lewis basicity

• Tathagata Mukherjee,
• Soumik Biswas,
• Andreas Ehnbom,
• Subrata K. Ghosh,
• Ibrahim El-Zoghbi,
• Nattamai Bhuvanesh,
• Hassan S. Bazzi and
• John A. Gladysz

Beilstein J. Org. Chem. 2017, 13, 2486–2501, doi:10.3762/bjoc.13.246

• degradation under free radical chlorination conditions. However, no reactions were observed when RfnI were treated with Cl2 or NaOCl/HCl. Nonetheless, perfluoroalkyl iodides RfnI (n = 6–8, 10, 12) can be oxidized using various recipes (e.g., 80% H2O2 in trifluoroacetic acid anhydride) to the iodine(III) bis

Dialkyl dicyanofumarates and dicyanomaleates as versatile building blocks for synthetic organic chemistry and mechanistic studies

• Grzegorz Mlostoń and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 2235–2251, doi:10.3762/bjoc.13.221

• aromatic systems. Miscellaneous reactions The oxidation of E-1a with H2O2 in acetonitrile gave oxirane 101, which subsequently was used for reactions with diverse nucleophiles [80] (Scheme 32). Upon treatment with diheptyl sulfide, 101 was transformed into ethoxalyl cyanide (102) [81]. The aziridination of

• ). Formation of disulfides through reaction of thiols with E-1a. Formation of CT salts of E-1 with Mn2+ and Cr2+ metallocenes through one-electron transfer. Oxidation of diethyl dicyanofumarate (E-1a) with H2O2 to give oxirane 101. The aziridination of E-1b through nitrene addition. Acknowledgements The

Phosphonic acid: preparation and applications

• Charlotte M. Sevrain,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2017, 13, 2186–2213, doi:10.3762/bjoc.13.219

• esterified with N-hydroxy-2-thiopyridone in the presence of DCC to produce 134 (Figure 37). This compound 134 was added to P4 solubilized in THF and was stirred for 30 minutes before replacing THF by DME. Then, H2O2 was added portion-wise and the solution was heated at reflux to produce the phosphonic acid

• 135. For some compounds, the reaction with H2O2 occurred at rt and then SO2 is added to complete the oxidation reaction. The work-up is, however, tedious because some excess of P4 must be removed without any contact with oxygen. This procedure was applied to natural compounds including lipophilic