NHC-catalyzed enantioselective synthesis of β-trifluoromethyl-β-hydroxyamides

• Alyn T. Davies,
• Mark D. Greenhalgh,
• Alexandra M. Z. Slawin and
• Andrew D. Smith

Beilstein J. Org. Chem. 2020, 16, 1572–1578, doi:10.3762/bjoc.16.129

• [54]. We have previously applied these precursors in the NHC-catalyzed formal [2 + 2] cycloadditions between α-aroyloxyaldehydes and perfluoroalkyl-substituted ketones using NHC precatalyst 3 to produce polyfluorinated oxetanes and β-perfluoroalkyl-β-hydroxyamides after derivatization [55]. In this

In silico rationalisation of selectivity and reactivity in Pd-catalysed C–H activation reactions

• Liwei Cao,
• Mikhail Kabeshov,
• Steven V. Ley and
• Alexei A. Lapkin

Beilstein J. Org. Chem. 2020, 16, 1465–1475, doi:10.3762/bjoc.16.122

• functionalization of C–H bonds is a powerful strategy for the synthesis and derivatization of organic molecules [12]. Homogeneous catalysis employing transition metal complexes has been widely accepted as one of the most efficient ways to perform C–H activation-based synthesis with high selectivity under relatively

Photocatalysis with organic dyes: facile access to reactive intermediates for synthesis

• Stephanie G. E. Amos,
• Marion Garreau,
• Luca Buzzetti and
• Jerome Waser

Beilstein J. Org. Chem. 2020, 16, 1163–1187, doi:10.3762/bjoc.16.103

• heteroarylated to give the desired dehalogenated products 13.3 or arylheteroarenes 13.4. Other organic dyes, such as dicyanoanthracene (OD5) and rhodamine 6G (OD14), have been successfully used in similar conPET strategies for the aryl radical-mediated derivatization of aryl bromides [82][83]. A similar double

A cyclopeptide and three oligomycin-class polyketides produced by an underexplored actinomycete of the genus Pseudosporangium

• Shun Saito,
• Kota Atsumi,
• Tao Zhou,
• Keisuke Fukaya,
• Daisuke Urabe,
• Naoya Oku,
• Md. Rokon Ul Karim,
• Hisayuki Komaki and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 1100–1110, doi:10.3762/bjoc.16.97

• -acetyl-ʟ-Tyr-ʟ-Pro-ʟ-Trp, was determined by a combination of spectroscopic analyses, chemical derivatization, ECD calculation, and DFT-based theoretical chemical shift calculation, revealing the presence of an (Sa)-axial chirality around the biaryl bond. Compounds 2–4 lacked hydroxylation on the side

Exploring the scope of DBU-promoted amidations of 7-methoxycarbonylpterin

• Anna R. Bockman and
• Jeffrey M. Pruet

Beilstein J. Org. Chem. 2020, 16, 509–514, doi:10.3762/bjoc.16.46

• bypassed the problematic insolubility and assisted in derivatization [14][15][16]. In addition to this improvement in solubility, we can further take advantage of a mechanistic role of DBU, as it catalyzes the ester-to-amide transformation, allowing for 7-methoxycarbonylpterin (7-CMP, 1) to smoothly

Copper-catalyzed enantioselective conjugate addition of organometallic reagents to challenging Michael acceptors

• Delphine Pichon,
• Jennifer Morvan,
• Christophe Crévisy and
• Marc Mauduit

Beilstein J. Org. Chem. 2020, 16, 212–232, doi:10.3762/bjoc.16.24

• reagents to these challenging Michael acceptors, with excellent regio- and enantioselectivity. Furthermore, thanks to their easy derivatization, the resulting chiral conjugated products could be converted into various natural products. The aim of this tutorial review is to summarize recent advances

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

• with thionyl chloride followed by derivatization with (S)-(−)-phenylalanine methyl ester. The applicability of this modified electrode [(S)-CelPheM] was tested by using it as a cathode for the electrochemical reduction of 4-acetylpyridine (1). GC analysis of the product indicated the formation of the

Plasma membrane imaging with a fluorescent benzothiadiazole derivative

• Pedro H. P. R. Carvalho,
• Jose R. Correa,
• Karen L. R. Paiva,
• Daniel F. S. Machado,
• Jackson D. Scholten and
• Brenno A. D. Neto

Beilstein J. Org. Chem. 2019, 15, 2644–2654, doi:10.3762/bjoc.15.257

• application of water-soluble plasma membrane probes [17][18]. We have been developing a new class of selective bioprobes based on the derivatization of the 2,1,3-benzothiadiazole (BTD) core (Figure 1) [19][20][21][22]. After we disclosed the use of these BTD derivatives as a new class of selective

Archangelolide: A sesquiterpene lactone with immunobiological potential from Laserpitium archangelica

• Silvie Rimpelová,
• Michal Jurášek,
• Lucie Peterková,
• Jiří Bejček,
• Vojtěch Spiwok,
• Miloš Majdl,
• Michal Jirásko,
• Miloš Buděšínský,
• Juraj Harmatha,
• Eva Kmoníčková,
• Pavel Drašar and
• Tomáš Ruml

Beilstein J. Org. Chem. 2019, 15, 1933–1944, doi:10.3762/bjoc.15.189

• data. Compound 1 was crystalized from a mixture of diethyl ether/hexanes (mp 108–111 °C) [14] and compound 2 from a mixture of toluene/Et2O (mp 190–192 °C) [12]. Derivatization of compound 1 with a dansyl probe In order to evaluate the intracellular localization and the fate of compound 1 in living

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

• hydrolysis. Installation of the allyl group at the nitrogen atom required prior derivatization as an oxazolidin-2-one and Birch reduction to furnish 204. To construct a properly functionalized piperidine ring olefin metathesis was performed to supply the key intermediate 205. Taking advantage of the steric

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

• organic reactions. In the syntheses of IPs, various forms of copper viz., salts, complexes, MOFs, oxides, and nanoparticles (NPs) have been used as the catalytic system in both multicomponent reactions (MCRs) as well as derivatization methodologies. The role of palladium in synthetic chemistry Pd

• used for functionalization/derivatization reactions compared to MCRs in the syntheses of IPs. The role of lanthanum/scandium/nickel/vanadium in synthetic chemistry The application of scandium complexes in organic chemistry has been very scarce due to their low availability and difficulties in

Efficient resolution of racemic crown-shaped cyclotriveratrylene derivatives and isolation and characterization of the intermediate saddle isomer

• Sven Götz,
• Andreas Schneider and
• Arne Lützen

Beilstein J. Org. Chem. 2019, 15, 1339–1346, doi:10.3762/bjoc.15.133

• from a couple of days at 40 °C to only a few hours at 70 °C in ethanol which sets the limits for further derivatization. a) Chromatogram of an analytical separation of (rac)-1 on a CHIRALPAK IB column as the stationary phase and MeOH as the mobile phase, 298 K, flow rate: 0.5 mL min−1; b) ECD-spectra

Remarkable effect of alkynyl substituents on the fluorescence properties of a BN-phenanthrene

• Alberto Abengózar,
• David Sucunza,
• Patricia García-García and
• Juan J. Vaquero

Beilstein J. Org. Chem. 2019, 15, 1257–1261, doi:10.3762/bjoc.15.122

• alkynyl substituents, as their presence in PAHs is known to alter the fluorescence properties thereof markedly [27][28][29]. In this regard, we have recently described a methodology for the synthesis of a chloro-substituted BN-benzo[c]phenanthrene and its subsequent derivatization via palladium-catalyzed

• cross-coupling reactions [30], and we envisioned that this reaction could be used to prepare C7 substituted BN-phenanthrenes (Figure 1). Herein we report the synthesis of chloro-substituted BN-phenanthrene 1b, its derivatization via palladium-catalyzed cross-coupling reactions and the significant effect

Steroid diversification by multicomponent reactions

• Leslie Reguera,
• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Daniel G. Rivera

Beilstein J. Org. Chem. 2019, 15, 1236–1256, doi:10.3762/bjoc.15.121

• materials for relevant MCRs such as those based on imine and isocyanide. The focus is mainly posed on proving the amenability of MCRs for the diversity-oriented derivatization of naturally occurring steroids and the construction of complex steroid-based platforms for drug discovery, chemical biology and

• supramolecular chemistry applications. Keywords: conjugation; heterocycles; macrocycles; multicomponent reactions; steroids; Review 1 Introduction The utilization of multicomponent reactions (MCRs) [1] for the derivatization of biomolecules has continuously grown over the last years. These diversity-oriented

• steroid biological functions. Such oxygenated and alkene groups represent the entrance door for subsequent synthetic modifications, including the incorporation of MCR reactive functionalities. In the last two decades, MCRs have emerged as effective tools for the rapid derivatization of steroidal skeletons

Synthesis of a novel category of pseudo-peptides using an Ugi three-component reaction of levulinic acid as bifunctional substrate, amines, and amino acid-based isocyanides

• Maryam Khalesi,
• Azim Ziyaei Halimehjani and
• Jürgen Martens

Beilstein J. Org. Chem. 2019, 15, 852–857, doi:10.3762/bjoc.15.82

• of an ester functional group in the structure of products makes them suitable substrates for further derivatization. Synthesis of functionalized 5-membered lactams using Ugi reaction. aIsolated yield for mixture of diastereomers. bThe ratio of diastereomers was determined by 1H NMR analysis

New α- and β-cyclodextrin derivatives with cinchona alkaloids used in asymmetric organocatalytic reactions

• Iveta Chena Tichá,
• Simona Hybelbauerová and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2019, 15, 830–839, doi:10.3762/bjoc.15.80

• modification of native CD skeletons with new functional groups enhances the application of CDs and provides access to new organic chemistry transformations and catalytic systems. Among the approaches used for chemical derivatization of CD skeletons, monosubstitution on the primary rim of CD (Figure 1) is a

Synthesis of acylglycerol derivatives by mechanochemistry

• Karen J. Ardila-Fierro,
• Andrij Pich,
• Marc Spehr,
• José G. Hernández and
• Carsten Bolm

Beilstein J. Org. Chem. 2019, 15, 811–817, doi:10.3762/bjoc.15.78

• relevant building blocks with mechanochemistry has further been shown by the recent mechanochemical protocols to transform nucleoside and nucleotide substrates (Figure 1) [18][19]. On the other hand, reports on mechanochemical protocols for the synthesis or derivatization of lipids are scarce [20][21

Efficient synthesis of 4-substituted-ortho-phthalaldehyde analogues: toward the emergence of new building blocks

• Clémence Moitessier,
• Ahmad Rifai,
• Pierre-Edouard Danjou,
• Isabelle Mallard and
• Francine Cazier-Dennin

Beilstein J. Org. Chem. 2019, 15, 721–726, doi:10.3762/bjoc.15.67

• dialdehydes in fluorometric methods with regard to the analysis of amino acids and biogenic amines [1][2][3]. It is also used as a derivatization reagent in order to quantify hydrazine by gas chromatography coupled with a mass spectrometer detector [4]. Recently, it was adopted for the analysis of γ

Synthesis and biological investigation of (+)-3-hydroxymethylartemisinin

• Toni Smeilus,
• Farnoush Mousavizadeh,
• Johannes Krieger,
• Xingzhao Tu,
• Marcel Kaiser and
• Athanassios Giannis

Beilstein J. Org. Chem. 2019, 15, 567–570, doi:10.3762/bjoc.15.51

• artemisinin synthesis that addresses these challenges and pave the way for derivatization of the (+)-artemisinin skeleton at positions not accessible using current methodology [14]. Based on our approach we report here on the synthesis and biological activity of the title compound (+)-3

Aqueous olefin metathesis: recent developments and applications

• Valerio Sabatino and
• Thomas R. Ward

Beilstein J. Org. Chem. 2019, 15, 445–468, doi:10.3762/bjoc.15.39

• some of the most representative catalysts developed for aqueous metathesis. Water-soluble catalysts are obtained by derivatization of classical catalysts G-II and HG-II (Figure 1a), resulting from the introduction of ionic tags and highly polar groups such as ammonium tags (Figure 1b) and PEGs (Figure

Study on the regioselectivity of the N-ethylation reaction of N-benzyl-4-oxo-1,4-dihydroquinoline-3-carboxamide

• Pedro N. Batalha,
• Luana da S. M. Forezi,
• Maria Clara R. Freitas,
• Nathalia M. de C. Tolentino,
• Ednilsom Orestes,
• José Walkimar de M. Carneiro,
• Fernanda da C. S. Boechat and
• Maria Cecília B. V. de Souza

Beilstein J. Org. Chem. 2019, 15, 388–400, doi:10.3762/bjoc.15.35

• , accomplished through temperatures above 200 °C, any derivatization afterwards should maintain the N–H carboxamide group intact, in order to provide the hydrogen bond donor group attached to C-3, which is usually related to the bioactivity of such compounds (Figure 2) [3][23]. In order to obtain an N1-alkylated

Sigmatropic rearrangements of cyclopropenylcarbinol derivatives. Access to diversely substituted alkylidenecyclopropanes

• Guillaume Ernouf,
• Jean-Louis Brayer,
• Christophe Meyer and
• Janine Cossy

Beilstein J. Org. Chem. 2019, 15, 333–350, doi:10.3762/bjoc.15.29

• rearrangement of cyanate 27 into isocyanate 28 (Scheme 15) [53]. All attempts to isolate isocyanate 28 were unsuccessful but derivatization of this latter reactive intermediate could be achieved in situ by addition of a broad range of nucleophiles, which were either used as co-solvents or added in excess. Thus

• derivatization in the case of other substrates devoid of a pyridine ring, several 3,3-dimethylcyclopropenylcarbinyl carbamates were engaged in the dehydration–[3,3]-sigmatropic rearrangement sequence under the previously used conditions but trifluoroacetic anhydride (1.5 equiv) and pyridine (1.5 equiv) were then

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

• oligosaccharides in order to improve the glycosylation efficiency [20][21]. In this approach, glucose instead of GlcA residues were employed in the oligosaccharide assembly and final oxidation and derivatization was carried out at the oligomer stage. Syndecan-1 glycopeptide containing a CS type A sequence was also

Asymmetric synthesis of a high added value chiral amine using immobilized ω-transaminases

• Antonella Petri,
• Valeria Colonna and
• Oreste Piccolo

Beilstein J. Org. Chem. 2019, 15, 60–66, doi:10.3762/bjoc.15.6

• °C. The eluent was H2O/CH3CN/DEA 70:30:0.1. Authentic standards were analyzed before analysis of the reaction mixtures. The enantiomeric excesses were determined after derivatization. An aliquot (50 mg) of the crude sample and 100 mg K2CO3 were added to a 15 mL volumetric flask and dissolved in 1 mL

N-Acylated amino acid methyl esters from marine Roseobacter group bacteria

• Hilke Bruns,
• Lisa Ziesche,
• Nargis Khakin Taniwal,
• Laura Wolter,
• Thorsten Brinkhoff,
• Jennifer Herrmann,
• Rolf Müller and
• Stefan Schulz

Beilstein J. Org. Chem. 2018, 14, 2964–2973, doi:10.3762/bjoc.14.276

• analysis, and structural proposals were derived from the mass spectra and by derivatization. Verification of compound structures was performed by synthesis. NABMEs, NAVMEs and NAGMEs are produced in low amounts only, making mass spectrometry the method of choice for their detection. The analysis of both EI

•  1). Localization of the double bond was established via DMDS derivatization as described previously [23]. Due to the low amounts no double bond position could be established for C14:1-NAME, while the double bond of C18:1 NAME was located at C-11. Similar as in AHLs, the double bond location in

• therefore proposed to be N-(hexadecanoyl)-2-aminobutyric acid methyl ester (7), while the earlier eluting J with m/z 353 compound was likely N-[(Z)-hexadec-9-enoyl]-2-aminobutyric acid methyl ester (8). The double bond position was determined by DMDS derivatization. The structures of both K and J were