Synthesis, docking study and biological evaluation of ᴅ-fructofuranosyl and ᴅ-tagatofuranosyl sulfones as potential inhibitors of the mycobacterial galactan synthesis targeting the galactofuranosyltransferase GlfT2

• Marek Baráth,
• Jana Jakubčinová,
• Zuzana Konyariková,
• Stanislav Kozmon,
• Katarína Mikušová and
• Maroš Bella

Beilstein J. Org. Chem. 2020, 16, 1853–1862, doi:10.3762/bjoc.16.152

• -fructofuranose derivatives 1 and started from the four known alcohols 4α, 5α, 5β and 6α [17]. Initial treatment of these alcohols with commercially available dibenzyl N,N-dimethylphosphoramidite as phosphorylating agent catalyzed by 1H-tetrazole and followed by direct oxidation with an excess of 3

• of the benzyl protecting groups in later stages of the synthesis. This advantage makes the overall synthesis of the target molecules one reaction step shorter in comparison with the synthesis starting from pivalate 11 (Scheme 3). With alcohols 17 in hand, the synthesis continued with their

One-pot synthesis of oxazolidinones and five-membered cyclic carbonates from epoxides and chlorosulfonyl isocyanate: theoretical evidence for an asynchronous concerted pathway

• Esra Demir,
• Ozlem Sari,
• Yasin Çetinkaya,
• Ufuk Atmaca,
• Safiye Sağ Erdem and
• Murat Çelik

Beilstein J. Org. Chem. 2020, 16, 1805–1819, doi:10.3762/bjoc.16.148

• oxazolidinones and five-membered cyclic carbonates of various structures. The most well-known strategies for the synthesis of oxazolidinones are the reaction of an amino alcohol with phosgene [5][22], the carbonylation reaction of β-amino alcohols with CO2 or dialkyl carbonates [23][24][25][26][27], the

• reaction in more detail. In our previous studies, we investigated the reactions of CSI with various substrates such as carboxylic acids, alkenes and allyl or benzyl alcohols [43][44][45][46]. As a continuation of these studies, we performed one-pot syntheses of the title compounds by optimizing the

• shorter reaction times under mild conditions using a simple purification method. Apparently, our protocol describes a reasonable methodology for the conversion of epoxides to protected 1,2-diols and 2-amino alcohols. Attention is drawn on these 1,2-oxygen and/or nitrogen units since they are present in

When metal-catalyzed C–H functionalization meets visible-light photocatalysis

• Lucas Guillemard and
• Joanna Wencel-Delord

Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147

Nonenzymatic synthesis of anomerically pure, mannosyl-based molecular probes for scramblase identification studies

• Giovanni Picca,
• Markus Probst,
• Simon M. Langenegger,
• Oleg Khorev,
• Peter Bütikofer,
• Anant K. Menon and
• Robert Häner

Beilstein J. Org. Chem. 2020, 16, 1732–1739, doi:10.3762/bjoc.16.145

• -Dod-NBD was obtained in 10 steps, starting from citronellol and tert-butyldimethylsilyl (TBDMS)-protected dodecanediol [39]. The reaction of either of the alcohols with the sugar phosphoramidite using ETT led to phosphite intermediates 1a and 1b, respectively. The intermediates were then oxidized with

Tuneable access to indole, indolone, and cinnoline derivatives from a common 1,4-diketone Michael acceptor

• Dalel El-Marrouki,
• Sabrina Touchet,
• Abderrahmen Abdelli,
• Hédi M’Rabet,
• Mohamed Lotfi Efrit and
• Philippe C. Gros

Beilstein J. Org. Chem. 2020, 16, 1722–1731, doi:10.3762/bjoc.16.144

• ). The nitrenones 3a–d were obtained in three steps from the appropriate commercially available cyclohexenones (Scheme 2). First, a Baylis–Hillman reaction between cyclohexanone and formaldehyde led to the formation of the corresponding Baylis–Hillman alcohols 1a/b in good yield [58], followed by a DMAP

• -catalyzed acetylation of these alcohols, which gave the corresponding acetates 2a–d [59]. The nitrenones 3a–d were finally obtained in an acceptable yield by reacting the acetate derivatives with the appropriate nitroalkanes [60]. The next step was the transformation of the nitro group of 3a–d via the Nef

• aprotic solvents, other than toluene (Table 1, entries 7 and 8), the reaction produced complex mixtures of degradation products, and using alcohols had a notable impact on the reaction contents. Indeed, going from ethanol to propanol, and thus increasing the refluxing temperature, led to the indolone 7b

One-pot synthesis of isosorbide from cellulose or lignocellulosic biomass: a challenge?

• Isaline Bonnin,
• Raphaël Mereau,
• Thierry Tassaing and
• Karine De Oliveira Vigier

Beilstein J. Org. Chem. 2020, 16, 1713–1721, doi:10.3762/bjoc.16.143

• conversion of cellulose and even spruce in a one-step hydrogenolysis reactions to form C4 to C6 sugar alcohols [20]. For the C6 sugar alcohols including the isosorbide formation, the yield was below 6% whatever catalyst was used at 160 °C, under 50 bar of H2 in a 36 mL stainless steel autoclave equipped with

Pauson–Khand reaction of fluorinated compounds

• Jorge Escorihuela,
• Daniel M. Sedgwick,
• Alberto Llobat,
• Mercedes Medio-Simón,
• Pablo Barrio and
• Santos Fustero

Beilstein J. Org. Chem. 2020, 16, 1662–1682, doi:10.3762/bjoc.16.138

• described, including the use of metals other than cobalt (such as rhodium, iridium, titanium, ruthenium, nickel, and palladium), or the use of CO surrogates such as aldehydes, alcohols and formates. Recently, its utility in flow chemistry has also been described [42]. Intramolecular Pauson–Khand reactions

• trifluoromethyl-substituted allylic alcohols 4 and 5 afforded the corresponding cyclized products 9 and 10 (31% and 34% yield, respectively) as inseparable mixtures of diastereoisomers. Finally, 1,6-enyne 6, bearing a 4-fluorophenyl group on the olefin, stereoselectively produced trans-oriented arylcyclopentenone

Facile synthesis of 7-alkyl-1,2,3,4-tetrahydro-1,8-naphthyridines as arginine mimetics using a Horner–Wadsworth–Emmons-based approach

• Rhys A. Lippa,
• John A. Murphy and
• Tim N. Barrett

Beilstein J. Org. Chem. 2020, 16, 1617–1626, doi:10.3762/bjoc.16.134

• varying amine structure, constituting potential Arg–Gly components of Arg–Gly–Asp integrin inhibitors (Table 3). Where the aldehyde was not commercially available, N-Boc-protected alcohols were oxidised using IBX in refluxing ethyl acetate and used crude. Olefination required only a modest excess of base

• ; (ii) 7.4 M HCl, 100 °C, 3.5 h, 92% yield. Bases surveyed for the formation of phosphoramidate 13.a Optimisation of the formation of phosphonate 7 using s-BuLi as a base.a Cores synthesised by the sequence of olefination, reduction, and deprotection, and the corresponding starting alcohols and

Synthesis of new dihydroberberine and tetrahydroberberine analogues and evaluation of their antiproliferative activity on NCI-H1975 cells

• Giacomo Mari,
• Lucia De Crescentini,
• Serena Benedetti,
• Francesco Palma,
• Stefania Santeusanio and
• Fabio Mantellini

Beilstein J. Org. Chem. 2020, 16, 1606–1616, doi:10.3762/bjoc.16.133

• achieved as a pure pale yellow solid directly from the reaction medium with the best yields (Table 1, entry 7). In tetrahydrofuran (THF), in ethyl acetate (EtOAc), and in alcohols such as methanol, ethanol, isopropanol (MeOH, EtOH, iPrOH) the reaction furnishes a complicate profile, where the desired 2a is

Mechanochemical green synthesis of hyper-crosslinked cyclodextrin polymers

• Alberto Rubin Pedrazzo,
• Fabrizio Caldera,
• Marco Zanetti,
• Silvia Lucia Appleton,
• Nilesh Kumar Dhakar and
• Francesco Trotta

Beilstein J. Org. Chem. 2020, 16, 1554–1563, doi:10.3762/bjoc.16.127

• nearly quantitative yields, with the release of carbon dioxide and formation of IMH. The reaction kinetics of alcohols with N,N'-carbonyldiimidazole were generally slower, so the presence of reactive IM moieties may be particularly interesting for an easy functionalization via reaction with nucleophilic

Photoredox-catalyzed silyldifluoromethylation of silyl enol ethers

• Vyacheslav I. Supranovich,
• Vitalij V. Levin and
• Alexander D. Dilman

Beilstein J. Org. Chem. 2020, 16, 1550–1553, doi:10.3762/bjoc.16.126

• -donating functional groups. Substrates containing pyridine, furan, and thiophene as heterocyclic fragments were also successfully converted into the corresponding alcohols 4. However, in the reaction of the enol ether derived from 2-acetyl-N-methylpyrrole, ketone 3p did not undergo reduction with sodium

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

The McKenna reaction – avoiding side reactions in phosphonate deprotection

• Katarzyna Justyna,
• Joanna Małolepsza,
• Damian Kusy,
• Waldemar Maniukiewicz and
• Katarzyna M. Błażewska

Beilstein J. Org. Chem. 2020, 16, 1436–1446, doi:10.3762/bjoc.16.119

• ), and therefore its easy removal from the reaction mixture. Section 4: Exchange of chloride for bromide BTMS is known to act as brominating agent for various functional groups, such as alcohols [47][48], three- and four-membered cyclic ethers [49], and anomeric glycosyl acetates [50]. However, to the

An overview on disulfide-catalyzed and -cocatalyzed photoreactions

• Yeersen Patehebieke

Beilstein J. Org. Chem. 2020, 16, 1418–1435, doi:10.3762/bjoc.16.118

• co-workers reported a photoinduced oxidation of allyl alcohols to acrylaldehydes at room temperature, catalyzed by diphenyl disulfide derivatives [18]. In the proposed mechanism, disulfide is split by the photoirradiation to form thiyl radicals. Then, the abstraction of the α-hydrogen atom from allyl

• synthesize alcohols, and realizing the anti-Markovnikov regioselectivity is extremely challenging. In 2017, Lei and co-workers reported a class of disulfide-cocatalyzed anti-Markovnikov olefin hydration reactions [24]. In this reaction, 9-mesityl-10-methylacridinium (Acr+–Mes–ClO4−) and diphenyl disulfide

• are used as the photoredox catalyst to prepare the corresponding primary and secondary alcohols from terminal and internal olefins. The substrate scope is broad, with excellent regioselectivities and yields up to 96% (Scheme 17). Decarboxylation reactions Carboxylic acid often serves as an inexpensive

Recent synthesis of thietanes

• Jiaxi Xu

Beilstein J. Org. Chem. 2020, 16, 1357–1410, doi:10.3762/bjoc.16.116

• 143. A proton transfer generated hydroxyalkanethiolates 144 because the acidity of the thiols is higher than that of alcohols, the newly generated thiolates 144 underwent an intramolecularly nucleophilic displacement to give thietane-3-ols 145 [56] (Scheme 28). In a similar approach

Synthesis of 3-substituted isoxazolidin-4-ols using hydroboration–oxidation reactions of 4,5-unsubstituted 2,3-dihydroisoxazoles

• Lívia Dikošová,
• Júlia Laceková,
• Ondrej Záborský and
• Róbert Fischer

Beilstein J. Org. Chem. 2020, 16, 1313–1319, doi:10.3762/bjoc.16.112

• alcohols. As a consequence, we assumed that the hydroboration–oxidation reaction of 2,3-dihydroisoxazoles would be an excellent way to prevent this obstacle. Recently, Kang et al. [29] reported the first hydroboration–oxidation reaction of the 5-substituted 4-isoxazolines even though the access to 4

Oxime radicals: generation, properties and application in organic synthesis

• Igor B. Krylov,
• Stanislav A. Paveliev,
• Alexander S. Budnikov and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2020, 16, 1234–1276, doi:10.3762/bjoc.16.107

• as scavengers of C-centered radicals [9] and selective oxidation organocatalysts (for example, in the oxidation of alcohols to the corresponding carbonyl compounds [10][11]). Recently, highly reactive imidoxyl radicals (Figure 1, II) have found a wide application in the processes of hydrogen atom

The charge-assisted hydrogen-bonded organic framework (CAHOF) self-assembled from the conjugated acid of tetrakis(4-aminophenyl)methane and 2,6-naphthalenedisulfonate as a new class of recyclable Brønsted acid catalysts

• Svetlana A. Kuznetsova,
• Alexander S. Gak,
• Yulia V. Nelyubina,
• Vladimir A. Larionov,
• Han Li,
• Michael North,
• Vladimir P. Zhereb,
• Alexander F. Smol'yakov,
• Artem O. Dmitrienko,
• Michael G. Medvedev,
• Igor S. Gerasimov,
• Ashot S. Saghyan and
• Yuri N. Belokon

Beilstein J. Org. Chem. 2020, 16, 1124–1134, doi:10.3762/bjoc.16.99

• , including the ring opening of epoxides by water and alcohols. A Diels–Alder reaction between cyclopentadiene and methyl vinyl ketone was also catalyzed by F-1 in heptane. Depending on the polarity of the solvent mixture, the CAHOF F-1 could function as a purely heterogeneous catalyst or partly dissociate

• catalyst for the Brønsted acid-catalyzed ring opening reactions of epoxides with alcohols and water, with the latter reaction occurring in a three-phase medium. In addition, a Diels–Alder reaction was promoted by F-1 in heptane. Results and Discussion Mixing together aqueous solutions of two equivalents of

• alcohol 3 was unsuccessful (Table 1, run 15). Evidently, the catalytic properties of the CAHOF F-1 were superior to those of standard ion exchange materials under these reaction conditions. The CAHOF F-1 could also promote the ring opening of cyclohexene oxide (5) by alcohols (Scheme 3), with the

Fluorinated phenylalanines: synthesis and pharmaceutical applications

• Laila F. Awad and
• Mohammed Salah Ayoup

Beilstein J. Org. Chem. 2020, 16, 1022–1050, doi:10.3762/bjoc.16.91

• the esters 83 with boronic acids 84a,b afforded the substituted phenylalanine derivatives 85a,b, respectively [58]. Deprotection of the hydroxy group was achieved by treatment with TBAF in THF to give 86a,b. Finally, fluorination of the alcohols 86a,b with DAST followed by deprotection gave the

Accelerating fragment-based library generation by coupling high-performance photoreactors with benchtop analysis

• Quentin Lefebvre,
• Christophe Salomé and
• Thomas C. Fessard

Beilstein J. Org. Chem. 2020, 16, 982–988, doi:10.3762/bjoc.16.87

• of complex amines: bicyclopentanamines, azetidines, spiroazetidines, spiropyrrolidines and spiropiperidines. Functional group tolerance was probed by using functionalized building blocks bearing esters, carbamates, alcohols, tertiary amines, ethers, sulfones and fluorine atoms (Scheme 2 and Scheme 3

Recent applications of porphyrins as photocatalysts in organic synthesis: batch and continuous flow approaches

• Rodrigo Costa e Silva,
• Luely Oliveira da Silva,
• Aloisio de Andrade Bartolomeu,
• Timothy John Brocksom and
• Kleber Thiago de Oliveira

Beilstein J. Org. Chem. 2020, 16, 917–955, doi:10.3762/bjoc.16.83

• platform for dual catalysis due to their ability to promote both metallocatalysis and photocatalysis in a one-pot system [36][37][38][39]. Martin and co-workers carried out the C–O bond cleavage of alcohols using a cobalt porphyrin under visible light irradiation and a carbon monoxide atmosphere (Scheme 11

• application in the synthesis of quinazolin-4-(3H)-ones by the one-pot reaction between alcohols and 2-aminobenzamide under an oxidative quenching, visible light irradiation using air or oxygen as oxidant (60–81% yields). The authors propose the generation of the superoxide radical anion with the MOF. The

• alcohols to aldehydes without over-oxidation to the carboxylic acids using Pt/PCN-224(Zn), a Zn porphyrin MOF incorporated with Pt nanocrystals (NC), as photocatalyst [47]. According to the authors, the synergism between NC and the porphyrin is important for this transformation and a wide variety of

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

• catalytic oxidation of alcohols into aldehydes, thus mimicking the reactivity of galactose oxidase. Complexes 1 and 2, exhibiting a twisted tetracoordinated geometry, and a distorted square pyramidal geometry, respectively, were used in alcohol oxidation on a wide variety of mostly aromatic alcohols in the

• another family of galactose oxidase mimics based on copper(II) complex 4 bearing a non-innocent iminophenol-iminopyridine hybrid ligand 3 that performed two-electron oxidations of primary alcohols to aldehydes (Scheme 2) [15]. Catalyst 4 was fully characterized by combined EPR, cyclic voltammetry and

• large number of alcohols (5a–e) in the presence of base (KOH 1 mol %). An interesting strategy aiming to explore the possibility of interfacing the redox-activity with H-bonding ability inside the ligand coordination sphere has been disclosed by Swart and Garcia-Bosch [16], and relies on the design and

Efficient synthesis of dipeptide analogues of α-fluorinated β-aminophosphonates

• Marcin Kaźmierczak and
• Henryk Koroniak

Beilstein J. Org. Chem. 2020, 16, 756–762, doi:10.3762/bjoc.16.69

• shown that the regioselectivity of the nucleophilic fluorination of amino alcohols can be controlled depending on the fluorinating reagent used [30][31]. This work presents the optimization of nucleophilic fluorination conditions. What is more, we discuss the effect of the base used on the

• Pudovik reaction, but also improved its yield drastically (Table 1). The implementation of this allowed us to obtain the anti-isomer (1R,2S) in very good yields. There are not many literature examples of the regioselective fluorination of amino alcohols using by PyFluor (1) or PBSF (2). In general, the

• (BTMG) 8, tert-butylimino-tri(pyrrolidino)phosphorane (BTPP, 9, Figure 2) [21]. We screened the alcohols 5 against sulfonyl fluoride reagents 1 and 2 and a combination of selected bases 6–9 (Scheme 2). All reactions during the optimization step were carried out on a 0.1 mmol scale under an argon

Recent advances in Cu-catalyzed C(sp³)–Si and C(sp³)–B bond formation

• Balaram S. Takale,
• Ruchita R. Thakore,
• Elham Etemadi-Davan and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2020, 16, 691–737, doi:10.3762/bjoc.16.67

• ] are common partners in a variety of important cross-coupling reactions. They are also especially valuable precursors to other functional groups such as organic halides, alcohols [5][6][7], etc. Moreover, recent drug discovery efforts have shifted towards the incorporation of these non-natural

• ] described NHC–Cu (74)/base 1,2-additions at room temperature of silicon pro-nucleophiles onto aldehydes 81 leading to racemic silyl alcohols 82–87 (Scheme 17B). A detailed mechanistic study revealed that a Cu–Si species is involved, giving intermediate 77, which subsequently undergoes fast Brook

• alcohols 98–100, respectively. Palladium was no longer needed for these transformations. The scope of the reaction with ketones was not limited to diaryl species and aryl ketones participated in the reaction, including those with more hindered alkyl groups (Scheme 19) [44]. This discovery was followed by a

Synthesis of disparlure and monachalure enantiomers from 2,3-butanediacetals

• Adam Drop,
• Hubert Wojtasek and
• Bożena Frąckowiak-Wojtasek

Beilstein J. Org. Chem. 2020, 16, 616–620, doi:10.3762/bjoc.16.57

• bromide or n-pentyltriphenylphosphonium bromide followed by reduction of the double bonds were performed first giving derivatives 24 and 25 containing the shorter carbon chains of the pheromones. Aldehydes 26 and 27 were obtained after removal of the protecting groups from the alcohols in compounds 24 and