Metal-free synthesis of biarenes via photoextrusion in di(tri)aryl phosphates

• Hisham Qrareya,
• Lorenzo Meazza,
• Stefano Protti and
• Maurizio Fagnoni

Beilstein J. Org. Chem. 2020, 16, 3008–3014, doi:10.3762/bjoc.16.250

• active compound is a common practice in medicinal chemistry [1][2][3]. In particular, the biaryl moiety is a privileged scaffold largely present in the skeleton of natural substances [4][5][6][7] and in useful chiral ligands [8][9][10]. The synthesis of biaryl derivatives remains, however, a considerable

Synthesis of imidazo[1,5-a]pyridines via cyclocondensation of 2-(aminomethyl)pyridines with electrophilically activated nitroalkanes

• Dmitrii A. Aksenov,
• Nikolai A. Arutiunov,
• Vladimir V. Maliuga,
• Alexander V. Aksenov and
• Michael Rubin

Beilstein J. Org. Chem. 2020, 16, 2903–2910, doi:10.3762/bjoc.16.239

• ]pyridines; nitroalkanes; polyphosphoric acid; Introduction It is hard to overstate the importance of imidazo[1,5-a]pyridines in modern organic and medicinal chemistry. Several natural alkaloids possessing this core were isolated from marine sponges, for example, cribrostatin 6 (Figure 1) [1][2][3]. The

• Within the last few years, we have developed and implemented a number of novel synthetic methodologies in our laboratories, involving acid-mediated cascade transformations of nitroalkenes and nitroalkanes, which target materials science and medicinal chemistry applications. It was demonstrated that upon

Vicinal difluorination as a C=C surrogate: an analog of piperine with enhanced solubility, photostability, and acetylcholinesterase inhibitory activity

• Yuvixza Lizarme-Salas,
• Alexandra Daryl Ariawan,
• Ranjala Ratnayake,
• Hendrik Luesch,
• Angela Finch and
• Luke Hunter

Beilstein J. Org. Chem. 2020, 16, 2663–2670, doi:10.3762/bjoc.16.216

• Yuvixza Lizarme-Salas Alexandra Daryl Ariawan Ranjala Ratnayake Hendrik Luesch Angela Finch Luke Hunter School of Chemistry, University of New South Wales (UNSW), Sydney NSW 2052, Australia Department of Medicinal Chemistry and Center for Natural Products, Drug Discovery and Development (CNPD3

• compound for medicinal chemistry. However, piperine has some problematic physicochemical properties including poor aqueous solubility and a susceptibility to UV-induced degradation. In this work, we designed an analog of piperine in which the central conjugated hydrocarbon chain is replaced with a vicinal

• for E-alkenes in medicinal chemistry. Keywords: Alzheimer's disease; bioisostere; conformational analysis; gauche effect; stereoselective synthesis; Introduction Piperine (1, Figure 1) is a well-known natural product that is derived from peppercorns [1][2][3]. Many biological studies of 1 have been

Chan–Evans–Lam N1-(het)arylation and N1-alkеnylation of 4-fluoroalkylpyrimidin-2(1H)-ones

• Viktor M. Tkachuk,
• Oleh O. Lukianov,
• Mykhailo V. Vovk,
• Isabelle Gillaizeau and
• Volodymyr A. Sukach

Beilstein J. Org. Chem. 2020, 16, 2304–2313, doi:10.3762/bjoc.16.191

• , heterocyclic analogues of activated ketimines (Figure 1), thus offering potential applications in the design of new heterocyclic chemotypes [21][22][23][24][25]. Compounds I are precursors of trifluoromethyl-substituted dihydropyrimidine derivatives which appear as original and potent scaffolds in medicinal

• chemistry, given the great importance of fluorinated groups in drug discovery [26][27][28][29]. On the strength of these results, herein we aim at extending the range of available compounds I by the introduction of (het)aryl and alkenyl substituents at the N1 position of the pyrimidine ring. Such

Photosensitized direct C–H fluorination and trifluoromethylation in organic synthesis

• Shahboz Yakubov and
• Joshua P. Barham

Beilstein J. Org. Chem. 2020, 16, 2151–2192, doi:10.3762/bjoc.16.183

• Shahboz Yakubov Joshua P. Barham Fakultät für Chemie und Pharmazie, Universität Regensburg, Universitätsstraße 31, 93040 Regensburg, Germany 10.3762/bjoc.16.183 Abstract The importance of fluorinated products in pharmaceutical and medicinal chemistry has necessitated the development of synthetic

• : Here, we briefly summarize the importance of fluorine atoms in organic molecules in the context of medicinal chemistry, materials chemistry, analytical chemistry and in the mechanistic studies of synthetic reactions. The importance of fluorination reactions in organic synthesis is reviewed exhaustively

Lipophilicity trends upon fluorination of isopropyl, cyclopropyl and 3-oxetanyl groups

• Benjamin Jeffries,
• Zhong Wang,
• Robert I. Troup,
• Anaïs Goupille,
• Jean-Yves Le Questel,
• Charlene Fallan,
• James S. Scott,
• Elisabetta Chiarparin,
• Jérôme Graton and
• Bruno Linclau

Beilstein J. Org. Chem. 2020, 16, 2141–2150, doi:10.3762/bjoc.16.182

• Nantes, France Medicinal Chemistry, Oncology R&D, AstraZeneca, Cambridge CB4 0WG, UK 10.3762/bjoc.16.182 Abstract A systematic comparison of lipophilicity modulations upon fluorination of isopropyl, cyclopropyl and 3-oxetanyl substituents, at a single carbon atom, is provided using directly comparable

• contrast to the result observed for C1 (see above, Figure 3). As discussed in the Introduction, converting acyclic alkanes to cyclopropane equivalents is a frequently used tactic in medicinal chemistry. The pairwise comparison of the isopropyl with the cyclopropyl substructures is best discussed via Figure

Reactions of 3-aryl-1-(trifluoromethyl)prop-2-yn-1-iminium salts with 1,3-dienes and styrenes

• Thomas Schneider,
• Michael Keim,
• Bianca Seitz and
• Gerhard Maas

Beilstein J. Org. Chem. 2020, 16, 2064–2072, doi:10.3762/bjoc.16.173

• years, a trifluoromethyl substituent has been included quite often in the design of compounds which were developed for applications in various fields, such as biological and medicinal chemistry, agrochemicals, transition metal ligands, and materials science [1][2][3][4][5]. The particular

Controlling the stereochemistry in 2-oxo-aldehyde-derived Ugi adducts through the cinchona alkaloid-promoted electrophilic fluorination

• Yuqing Wang,
• Gaigai Wang,
• Anatoly A. Peshkov,
• Ruwei Yao,
• Muhammad Hasan,
• Manzoor Zaman,
• Chao Liu,
• Stepan Kashtanov,
• Olga P. Pereshivko and
• Vsevolod A. Peshkov

Beilstein J. Org. Chem. 2020, 16, 1963–1973, doi:10.3762/bjoc.16.163

• associated with controlling their stereochemical outcome [33][34][35] severely restrict their applicability in medicinal chemistry [36]. The typical Passerini three-component reaction (P-3CR) of a carboxylic acid 1, an aldehyde 2, and an isocyanide 3 being conducted in a polar-aprotic solvent such as THF or

Natural dolomitic limestone-catalyzed synthesis of benzimidazoles, dihydropyrimidinones, and highly substituted pyridines under ultrasound irradiation

• Kumar Godugu,
• Venkata Divya Sri Yadala,
• Mohammad Khaja Mohinuddin Pinjari,
• Trivikram Reddy Gundala,
• Lakshmi Reddy Sanapareddy and
• Chinna Gangi Reddy Nallagondu

Beilstein J. Org. Chem. 2020, 16, 1881–1900, doi:10.3762/bjoc.16.156

• aforesaid nitrogen-containing heterocycles. Benzimidazoles are an important class of N-heterocycles due to their potential applications in both biology and medicinal chemistry [10][11][12][13]. These compounds are used in the treatment of diseases, such as obesity, ischemia-reperfusion injury, hypertension

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

• features when working with biological systems. Thus, a variety of functionalized purines nucleosides that are potentially of great importance in medicinal chemistry were obtained in good yields. In contrast to C(sp2)–H bonds, C(sp3)–H bond activation is much more challenging. Inspired by the potential of

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

• ; indoles 6, indolones 7, and cinnolines 8, starting from common substrates 1,4-diketones 5 and primary amines. The protocols developed here used mild conditions, were functional-group tolerant, transition-metal-free, proceeded in moderate to good yield, and could therefore easily be used in medicinal

• chemistry projects for the rapid access to a wide range of variously substituted compounds for structure–activity relationship studies. The biological activity of the molecules is currently being studied. Examples of bioactive nitrogen-containing heterocycles (indole [9], indolone [10], and cinnoline [11

Microwave-assisted efficient one-pot synthesis of N²-(tetrazol-5-yl)-6-aryl/heteroaryl-5,6-dihydro-1,3,5-triazine-2,4-diamines

• Moustafa Sherief Moustafa,
• Ramadan Ahmed Mekheimer,
• Saleh Mohammed Al-Mousawi,
• Mohamed Abd-Elmonem,
• Hesham El-Zorba,
• Afaf Mohamed Abdel Hameed,
• Tahany Mahmoud Mohamed and
• Kamal Usef Sadek

Beilstein J. Org. Chem. 2020, 16, 1706–1712, doi:10.3762/bjoc.16.142

• -2,4-diamines; one-pot synthesis; X-ray crystallography; Introduction The family of triazines is of considerable interest in fields related to organic and medicinal chemistry. 2,4-Diaminotriazines are privileged scaffolds exhibiting diverse biological activities such as antibacterial [1], anti-HSV-1

Models of necessity

• Timothy Clark and
• Martin G. Hicks

Beilstein J. Org. Chem. 2020, 16, 1649–1661, doi:10.3762/bjoc.16.137

• -atomic representation [73]. These force fields have attained a remarkable level of accuracy for proteins, so that force-field based simulations have become predictive in many fields of biology, medicinal chemistry and biophysics [74]. Models, approximations and paradigms Despite the many advances made

Rearrangement of o-(pivaloylaminomethyl)benzaldehydes: an experimental and computational study

• Csilla Hargitai,
• Györgyi Koványi-Lax,
• Tamás Nagy,
• Péter Ábrányi-Balogh,
• András Dancsó,
• Gábor Tóth,
• Judit Halász,
• Angéla Pandur,
• Gyula Simig and
• Balázs Volk

Beilstein J. Org. Chem. 2020, 16, 1636–1648, doi:10.3762/bjoc.16.136

• Csilla Hargitai Gyorgyi Kovanyi-Lax Tamas Nagy Peter Abranyi-Balogh Andras Dancso Gabor Toth Judit Halasz Angela Pandur Gyula Simig Balazs Volk Directorate of Drug Substance Development, Egis Pharmaceuticals Plc., P.O. Box 100, H-1475 Budapest, Hungary Medicinal Chemistry Research Group, Research

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

• acquiring HRMS data. Funding Financial support for this work was provided by GSK via the GSK/University of Strathclyde Centre for Doctoral Training in Synthetic and Medicinal Chemistry. We thank EPSRC for further funding via Prosperity Partnership EP/S035990/1.

Photocatalyzed syntheses of phenanthrenes and their aza-analogues. A review

• Alessandra Del Tito,
• Havall Othman Abdulla,
• Davide Ravelli,
• Stefano Protti and
• Maurizio Fagnoni

Beilstein J. Org. Chem. 2020, 16, 1476–1488, doi:10.3762/bjoc.16.123

• ; phenanthridines; photocatalysis; radicals; visible light; Introduction Phenanthrenes are widely investigated compounds, due to the impressive number of diverse applications involving this scaffold, ranging from medicinal chemistry [1] to materials sciences, including their use in optoelectronics [2][3] and in

One-step route to tricyclic fused 1,2,3,4-tetrahydroisoquinoline systems via the Castagnoli–Cushman protocol

• Aleksandar Pashev,
• Nikola Burdzhiev and
• Elena Stanoeva

Beilstein J. Org. Chem. 2020, 16, 1456–1464, doi:10.3762/bjoc.16.121

• for the construction of these heteropolycycles is of great significance to both organic and medicinal chemistry. The Castagnoli–Cushman reaction (CCR) between cyclic enolizable anhydrides (such as succinic (5) [9], glutaric (6) [10], and the corresponding oxygen (7) [11], sulfur (8) [11], and nitrogen

One-pot synthesis of 1,3,5-triazine-2,4-dithione derivatives via three-component reactions

• Gui-Feng Kang and
• Gang Zhang

Beilstein J. Org. Chem. 2020, 16, 1447–1455, doi:10.3762/bjoc.16.120

• benign methodologies for the generation of structurally diverse triazinethione derivatives is still challenging in organic synthetic chemistry and medicinal chemistry. Multicomponent reactions (MCRs) gained much interest among synthetic organic chemists as well as in combinatorial chemistry and drug

• anticancer [10][11], antimicrobial [12], antiviral agents [13][14], and eosinophilia inhibitors [15]. Therefore, it is highly desirable to develop efficient and practical synthetic methods for triazinethione architectures and to expand the structure diversity of this class of compounds for medicinal

• chemistry demands. Several methods were reported for the synthesis of triazinethione analogs. One of the most popular methods involved the reaction of a carboximidamide [16], or urea [17] with isothiocyanates. The C=S bond in the latter is highly polar, with the carbon atom always positive and therefore

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

• and 4 (Figure 1), would be of particular interest in modern medicinal chemistry as eventual heterocyclic substructures. Results and Discussion At the beginning of our investigations, we envisaged that the above-mentioned 3-substituted 4-hydroxyisoxazolidines bearing no substituent at C5 could be

Photocatalytic trifluoromethoxylation of arenes and heteroarenes in continuous-flow

• Alexander V. Nyuchev,
• Ting Wan,
• Borja Cendón,
• Carlo Sambiagio,
• Job J. C. Struijs,
• Michelle Ho,
• Moisés Gulías,
• Ying Wang and
• Timothy Noël

Beilstein J. Org. Chem. 2020, 16, 1305–1312, doi:10.3762/bjoc.16.111

• could be useful in medicinal chemistry applications. In addition, although no beneficial effect could be achieved in flow by the addition of bases, we proved this has a significant effect on the reaction in batch, leading to higher yields. This discovery will be useful for the development of future

Anthelmintic drug discovery: target identification, screening methods and the role of open science

• Frederick A. Partridge,
• Ruth Forman,
• Carole J. R. Bataille,
• Graham M. Wynne,
• Marina Nick,
• Angela J. Russell,
• Kathryn J. Else and
• David B. Sattelle

Beilstein J. Org. Chem. 2020, 16, 1203–1224, doi:10.3762/bjoc.16.105

• can progress to trials as it would be a new mechanism of action for an anthelmintic, although some mitochondrial uncouplers, such as the veterinary medicine closantel, are active against Fasciola hepatica [168]. Recently, a medicinal chemistry effort was undertaken to determine the anthelmintic

Synthesis and anticancer activity of bis(2-arylimidazo[1,2-a]pyridin-3-yl) selenides and diselenides: the copper-catalyzed tandem C–H selenation of 2-arylimidazo[1,2-a]pyridine with selenium

• Mio Matsumura,
• Tsutomu Takahashi,
• Hikari Yamauchi,
• Shunsuke Sakuma,
• Yukako Hayashi,
• Tadashi Hyodo,
• Tohru Obata,
• Kentaro Yamaguchi,
• Yasuyuki Fujiwara and
• Shuji Yasuike

Beilstein J. Org. Chem. 2020, 16, 1075–1083, doi:10.3762/bjoc.16.94

• medicinal chemistry [19][20]. A number of clinically used drugs and clinical candidates, such as zolpidem, alpidem, saripidem, zolimidine, necopidem, and GSK812397 contain the imidazo[1,2-a]pyridine scaffold [21][22][23][24][25][26]. 3-(Arylselanyl)imidazo[1,2-a]pyridines IV were reported to act as

Copper-based fluorinated reagents for the synthesis of CF₂R-containing molecules (R ≠ F)

• Louise Ruyet and
• Tatiana Besset

Beilstein J. Org. Chem. 2020, 16, 1051–1065, doi:10.3762/bjoc.16.92

• the CF2SO2Ph group was further demonstrated by its conversion into the high value-added CF2H moiety after treatment with Mg/AcOH/AcONa. An in situ-generated copper-based CF2CH3 reagent A strong interest was dedicated to the CF2CH3 residue, an important moiety in medicinal chemistry [63]. Among the

Copper-catalysed alkylation of heterocyclic acceptors with organometallic reagents

• Yafei Guo and
• Syuzanna R. Harutyunyan

Beilstein J. Org. Chem. 2020, 16, 1006–1021, doi:10.3762/bjoc.16.90

• alkenylaluminium and alkylaluminium reagents to the β-substituted unsaturated conjugated lactams 25 was utilized (Scheme 7B) [32]. Chiral lactones are yet another interesting class of heterocyclic substrates that have attracted great attention because of their usefulness in both organic synthesis and medicinal

• chemistry. The copper-catalysed ACA of organozinc reagents to 5,6-dihydro-2-pyranone is one of the best methods to obtain chiral lactones. During the past two decades, the research groups of Chan, Hoveyda (who applied an approach depending on the trapping by an aldehyde), Mauduit, and Wang reported a

Synthesis of new asparagine-based glycopeptides for future scanning tunneling microscopy investigations

• Laura Sršan and
• Thomas Ziegler

Beilstein J. Org. Chem. 2020, 16, 888–894, doi:10.3762/bjoc.16.80

• highly important for resolving some of the most challenging topics in medicinal chemistry [4][6][7]. Due to the microheterogeneity of naturally occurring glycopeptides, which is the reason for the hampered isolation of these structures in a pure form from biological material, there is a great interest in