Borylated norbornadiene derivatives: Synthesis and application in Pd-catalyzed Suzuki–Miyaura coupling reactions

• Robin Schulte and
• Heiko Ihmels

Beilstein J. Org. Chem. 2022, 18, 368–373, doi:10.3762/bjoc.18.41

• identification of novel stable derivatives as well, such as 5b, 5c, and 5i. But unfortunately, there is no clear trend for a substituent effect on the reaction outcome, as both donor- and acceptor-substituted haloarenes resulted in essentially the same range of yields, i.e. from good yields (e.g., 4b, 4h, and 4j

Amamistatins isolated from Nocardia altamirensis

• Till Steinmetz,
• Wolf Hiller and
• Markus Nett

Beilstein J. Org. Chem. 2022, 18, 360–367, doi:10.3762/bjoc.18.40

• bacterium Nocardia altamirensis DSM 44997, which had originally been isolated from a microbial cave wall community and represents a non-pathogenic strain [5]. Our analysis led to the identification of six iron-chelating molecules belonging to the amamistatin family. Four of these compounds (1–4) have not

• was determined by HRESIMS with a molecular ion at m/z 716.3820 [M + H]+ (calcd for C36H54N5O10, 716.3820). A comparison with published data led to the identification of compound 5 as the known siderophore amamistatin B [7]. Compound 6 (2.4 mg) was isolated as a slight reddish oil. The molecular

Trichloroacetic acid fueled practical amine purifications

• Aleena Thomas,
• Baptiste Gasch,
• Enzo Olivieri and
• Adrien Quintard

Beilstein J. Org. Chem. 2022, 18, 225–231, doi:10.3762/bjoc.18.26

• dicyclohexylamine (Table 3, entry 1), a broad range of primary amines could also be separated from the aromatic impurities (Table 3, entries 2–10). As for other purification techniques, the challenge lies in the identification of the appropriate solvent to dissolve well the initial mixture and induce the amine–TCA

• importance, this technique is also efficient for the isolation of highly complex natural amines such as brucin, isolated in 57% yield using TCA (Table 3, entry 14). As mentioned, identification of a suitable solvent solubilizing the initial mixture and enabling precipitation/crystallization of the amine salt

Glycosylated coumarins, flavonoids, lignans and phenylpropanoids from Wikstroemia nutans and their biological activities

• Meifang Wu,
• Xiangdong Su,
• Yichuang Wu,
• Yuanjing Luo,
• Ying Guo and
• Yongbo Xue

Beilstein J. Org. Chem. 2022, 18, 200–207, doi:10.3762/bjoc.18.23

• neuroprotective effects [6]. As part of a continuing study of our group targeting at the identification of bioactive natural products from the medicinal plants and endophytes [7][8], the chemical constituents of the stems and roots of W. nutans were investigated. This work resulted into the isolation and

• identification of a new bis-coumarin glucoside 1, together with three known bis- and tricoumarin glucosides 2–4, two flavonoid glycosides 5 and 6, and eleven lignan glucosides 7–17 (Figure 1). Herein, we present the isolation and structural elucidation of these natural products and their in vitro biological

• chromatographed over a HW-40 CC eluting with MeOH to obtain six fractions (B5.4.1–5.4.6), further purified by semipreparative RP-HPLC using a mobile phase of MeCN/H2O (20: 80–50: 50 gradient system, v/v, 3 mL/min) to afford compounds 1 (7.0 mg), 2 (15.0 mg), 5 (20.0 mg), and 6 (10.0 mg). Identification of new

Peptide stapling by late-stage Suzuki–Miyaura cross-coupling

• Hendrik Gruß,
• Rebecca C. Feiner,
• Ridhiwan Mseya,
• David C. Schröder,
• Michał Jewgiński,
• Kristian M. Müller,
• Rafał Latajka,
• Antoine Marion and
• Norbert Sewald

Beilstein J. Org. Chem. 2022, 18, 1–12, doi:10.3762/bjoc.18.1

• macrocycle and of the Lys–His bond, which is part of the cross-link, is prevented by the stapling (Figure 3 and Supporting Information File 1, Figures S8 to S10). Conformational analysis The identification of two isomers of P5 by LC–MS led us investigate the possibility of diastereomers and conformers in the

A photochemical C=C cleavage process: toward access to backbone N-formyl peptides

• Haopei Wang and
• Zachary T. Ball

Beilstein J. Org. Chem. 2021, 17, 2932–2938, doi:10.3762/bjoc.17.202

• , byproducts or transiently stable intermediates were sometimes indicated by HPLC and/or NMR of these photocleavage reactions [16][17]. These observations prompted a more detailed study of the components present during photocleavage reactions of small-molecule models, leading to the identification of the N

First total synthesis of hoshinoamide A

• Haipin Zhou,
• Zihan Rui,
• Yiming Yang,
• Shengtao Xu,
• Yutian Shao and
• Long Liu

Beilstein J. Org. Chem. 2021, 17, 2924–2931, doi:10.3762/bjoc.17.201

• Entrepreneurship Program (Grant No. 2019CXXL077); Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology (Grant No. OHIC2020Y06).

Synthesis of highly substituted fluorenones via metal-free TBHP-promoted oxidative cyclization of 2-(aminomethyl)biphenyls. Application to the total synthesis of nobilone

• Ilya A. P. Jourjine,
• Lukas Zeisel,
• Jürgen Krauß and
• Franz Bracher

Beilstein J. Org. Chem. 2021, 17, 2668–2679, doi:10.3762/bjoc.17.181

• identification of the first representatives, dengibsin (1a) and dengibsinin (1b) in 1985 from the orchid Dendrobium gibsonii [1], numerous further natural fluorenones, typically bearing hydroxy and methoxy substituents, but also aminoalkyl side chains, as in caulophine (1e) [2] and caulophylline A (1f) [3], were

AlBr₃-Promoted stereoselective anti-hydroarylation of the acetylene bond in 3-arylpropynenitriles by electron-rich arenes: synthesis of 3,3-diarylpropenenitriles

• Yelizaveta Gorbunova,
• Dmitry S. Ryabukhin and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2021, 17, 2663–2667, doi:10.3762/bjoc.17.180

• 2m correspondingly were obtained; other regioisomers were not isolated in amounts that were high enough for their identification. This transformation was also tested with another strong Lewis acid, aluminum chloride (AlCl3), for the reaction of nitrile 1a with benzene. However, in this case, mainly

Ligand-dependent stereoselective Suzuki–Miyaura cross-coupling reactions of β-enamido triflates

• Tomáš Chvojka,
• Athanasios Markos,
• Svatava Voltrová,
• Radek Pohl and
• Petr Beier

Beilstein J. Org. Chem. 2021, 17, 2657–2662, doi:10.3762/bjoc.17.179

• base led to the identification of Pd(PPh3)4 (10 mol %), arylboronic acid (1 equiv), K3PO4 (2 equiv) in THF/H2O 1:1 as ideal conditions providing enamides 2aa and 3aa in a 93:7 ratio in 90% 19F NMR yield (Table S1 in Supporting Information File 1). The optimized conditions were applied to the scope

Strategies for the synthesis of brevipolides

• Yudhi D. Kurniawan and
• A'liyatur Rosyidah

Beilstein J. Org. Chem. 2021, 17, 2399–2416, doi:10.3762/bjoc.17.157

• correlation with biological activity. This analysis attributed two detected [M − H]− signals to dihydrobrevipolides C and F. Nevertheless, further structural identification was not performed. Conclusion The characteristic structural features of 5,6-dihydro-α-pyrone derivatives isolated from Hyptis brevipes

Isolation and characterization of new phenolic siderophores with antimicrobial properties from Pseudomonas sp. UIAU-6B

• Emmanuel T. Oluwabusola,
• Olusoji O. Adebisi,
• Fernando Reyes,
• Kojo S. Acquah,
• Mercedes De La Cruz,
• Larry L. Mweetwa,
• Joy E. Rajakulendran,
• Digby F. Warner,
• Deng Hai,
• Rainer Ebel and
• Marcel Jaspars

Beilstein J. Org. Chem. 2021, 17, 2390–2398, doi:10.3762/bjoc.17.156

• × 250 mm) columns, and a mobile phase solvent gradient consisting of H2O (Milli-Q filter water 18 MΩ·cm, Millipore, Germany), 100% MeOH (Sigma-Aldrich, UK), and TFA (Sigma-Aldrich, UK). Bacterial isolation and identification The bacterial strain was isolated from soil sediments collected from the Oyun

Phenolic constituents from twigs of Aleurites fordii and their biological activities

• Kyoung Jin Park,
• Won Se Suh,
• Da Hye Yoon,
• Chung Sub Kim,
• Sun Yeou Kim and
• Kang Ro Lee

Beilstein J. Org. Chem. 2021, 17, 2329–2339, doi:10.3762/bjoc.17.151

•  2). Alkaline hydrolysis of 16 yielded codiacyanoglucoside (16a) and gallic acid (16b). The identification of 16a and 16b was conducted by comparison of their 1H NMR and MS data [24][25]. Consequently, the structure of 16 was determined to be codiacyano glucosyl-2′,6′-O-digallate, named

• analyzed by GC–MS. The identification of ᴅ-glucose and ʟ-rhamnose was carried out by coinjection of the hydrolysate with standard silylated samples, giving a single peak at 9.730 and 9.712 min, respectively. Authentic samples (Sigma-Aldrich, St. Louis, MO, USA) that were treated in the same way showed a

(Phenylamino)pyrimidine-1,2,3-triazole derivatives as analogs of imatinib: searching for novel compounds against chronic myeloid leukemia

• Luiz Claudio Ferreira Pimentel,
• Lucas Villas Boas Hoelz,
• Henayle Fernandes Canzian,
• Frederico Silva Castelo Branco,
• Andressa Paula de Oliveira,
• Vinicius Rangel Campos,
• Floriano Paes Silva Júnior,
• Rafael Ferreira Dantas,
• Jackson Antônio Lamounier Camargos Resende,
• Anna Claudia Cunha,
• Nubia Boechat and
• Mônica Macedo Bastos

Beilstein J. Org. Chem. 2021, 17, 2260–2269, doi:10.3762/bjoc.17.144

• 1980s, has led to the identification of the (phenylamino)pyrimidine (PAP) structure [5][6]. The addition of an additional pyridine ring to PAP raised its cellular activity, producing PAPP, which, after some more chemical modifications, culminated in imatinib (IMT) [7]. PAPP has been used to develop new

Constrained thermoresponsive polymers – new insights into fundamentals and applications

• Patricia Flemming,
• Alexander S. Münch,
• Andreas Fery and
• Petra Uhlmann

Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138

An initiator- and catalyst-free hydrogel coating process for 3D printed medical-grade poly(ε-caprolactone)

• Jochen Löblein,
• Thomas Lorson,
• Miriam Komma,
• Tobias Kielholz,
• Maike Windbergs,
• Paul D. Dalton and
• Robert Luxenhofer

Beilstein J. Org. Chem. 2021, 17, 2095–2101, doi:10.3762/bjoc.17.136

• spatially resolved polymer identification based on chemical functionalities. A unique peak at 1111 cm−1 was identified and is attributed to backbone stretching of aliphatic chains [ν(C–C)] in PCL. Also, a characteristic band at 829 cm−1 was detected which can be assigned to PHEMA and refers to the

Enantioenriched α-substituted glutamates/pyroglutamates via enantioselective cyclopropenimine-catalyzed Michael addition of amino ester imines

• Zara M. Seibel,
• Jeffrey S. Bandar and
• Tristan H. Lambert

Beilstein J. Org. Chem. 2021, 17, 2077–2084, doi:10.3762/bjoc.17.134

• active (Table 1, entry 6). With the identification of cyclopropenimine 5 as our optimal catalyst [44], we examined the effect of the reaction medium. Solvents such as benzene (Table 1, entry 7), TBME (Table 1, entry 8), and toluene (Table 1, entry 10) produced reactivities on par with ethyl acetate and

Natural products in the predatory defence of the filamentous fungal pathogen Aspergillus fumigatus

• Jana M. Boysen,
• Nauman Saeed and
• Falk Hillmann

Beilstein J. Org. Chem. 2021, 17, 1814–1827, doi:10.3762/bjoc.17.124

• epipolythiodioxopiperazine (ETP’s) class toxin of several fungal genera including Aspergillus, Penicillium, Trichoderma, and Leptosphaera (Figure 3) [112]. Among the ascomycetes, A. fumigatus may well be the major GT producer and the identification of its heterocyclic structure by Bell and colleagues in 1958 builds the

• have been widely used for the identification of virulence attributes of pathogenic fungi, including Aspergillus spp., for their similarity with human phagocytic cells [32]. Nevertheless, the precise identity of amoeboid, nematode and arthropod predators that target filamentous fungi in their

• ecological trigger for the production and identification of new bioactive compounds in the future. Schematic overview of fungal interactions in the environment. Fungi can be found in essentially all terrestrial habitats comprising saprophytic, parasitic, symbiotic or predatory lifestyles [6]. Independent of

Development of N-F fluorinating agents and their fluorinations: Historical perspective

• Teruo Umemoto,
• Yuhao Yang and
• Gerald B. Hammond

Beilstein J. Org. Chem. 2021, 17, 1752–1813, doi:10.3762/bjoc.17.123

• reported by Banks when quinuclidine was N-fluorinated with Selectfluor [62] (Scheme 67). Subsequently, in 2001, Shibata et al. presented full details of their studies including the definitive identification of N-fluorinated cinchona alkaloids by X-ray crystallography analysis and further applications [96

Volatile emission and biosynthesis in endophytic fungi colonizing black poplar leaves

• Christin Walther,
• Pamela Baumann,
• Katrin Luck,
• Beate Rothe,
• Peter H. W. Biedermann,
• Jonathan Gershenzon,
• Tobias G. Köllner and
• Sybille B. Unsicker

Beilstein J. Org. Chem. 2021, 17, 1698–1711, doi:10.3762/bjoc.17.118

• their own TPS genes and how these fungal volatiles influence plant–insect interactions. Identification of fungal TPS genes is a useful tool to assess the impact of fungal terpene emission on plant volatile composition and on plant–insect interactions. In this study, we isolated and identified endophytic

• these compounds. For this, identification of TPS genes in both plants and their fungal partners is crucial. Conclusion We showed that endophytic fungi isolated from mature black poplar trees emitted species-specific volatile blends. Almost all the endophytes here produced short-chain aliphatic alcohols

• were brought into pure culture on PDA medium using the same culturing conditions as above. Fresh mycelium was harvested from pure cultures for molecular identification of the morphospecies. Molecular identification of endophytic fungi DNA was extracted from fresh mycelium (approximately 5 cm in

Chemical approaches to discover the full potential of peptide nucleic acids in biomedical applications

• Nikita Brodyagin,
• Martins Katkevics,
• Venubabu Kotikam,
• Christopher A. Ryan and
• Eriks Rozners

Beilstein J. Org. Chem. 2021, 17, 1641–1688, doi:10.3762/bjoc.17.116

Total synthesis of ent-pavettamine

• Memory Zimuwandeyi,
• Manuel A. Fernandes,
• Amanda L. Rousseau and
• Moira L. Bode

Beilstein J. Org. Chem. 2021, 17, 1440–1446, doi:10.3762/bjoc.17.99

• ; pavettamine; polyamine; Introduction The identification and first reported synthesis of pavettamine (1) heralded the arrival of a novel and uniquely hydroxylated polyamine (PA) (Figure 1) [1]. In general, polyamines are described as aliphatic organic compounds with two or more primary amine substituents

Analogs of the carotane antibiotic fulvoferruginin from submerged cultures of a Thai Marasmius sp.

• Birthe Sandargo,
• Leon Kaysan,
• Rémy B. Teponno,
• Christian Richter,
• Benjarong Thongbai,
• Frank Surup and
• Marc Stadler

Beilstein J. Org. Chem. 2021, 17, 1385–1391, doi:10.3762/bjoc.17.97

• moderate antifungal activity. A recent find of a Marasmius species in Northern Thailand led, however, to the isolation and identification of five novel derivatives of this carotane-type sesquiterpenoid. The present study is dedicated to describing their isolation, and biological and physicochemical

• with an MCP 150 polarimeter (Anton Paar, Graz, Austria). The CD spectra were obtained from a JASCO spectropolarimeter, model J-815 (Pfungstadt, Germany). The UV spectra were recorded on a Shimadzu UV–vis spectrophotometer UV-2450 (Duisburg, Germany). Isolation and identification of fungal material

Icilio Guareschi and his amazing “1897 reaction”

• Gian Cesare Tron,
• Alberto Minassi,
• Giovanni Sorba,
• Mara Fausone and
• Giovanni Appendino

Beilstein J. Org. Chem. 2021, 17, 1335–1351, doi:10.3762/bjoc.17.93

• can hardly be underestimated. In those times, the only methods available for the identification of compounds were holistic, that is, associated with the whole molecular construct (melting point and boiling point, optical rotation, diffraction index, density), and color reactions were therefore

• critical for the identification of functional groups, being the equivalent of what next became IR spectroscopy. Schiff himself had contributed to this development with the discovery of the sulfite-decolorized fuchsine test for aldehydes and with the popularization of the biuret test for peptide bonds. It

• to the identification of pharmaceutical phenols by Sigmund Lustgarten, is carried out under anhydrous conditions, either on an alkaline salt of the phenol or by adding solid KOH or NaOH to a chloroform solution of the phenol [5][21]. Reimer and Tiemann discovered that, in the presence of water, the

A new glance at the chemosphere of macroalgal–bacterial interactions: In situ profiling of metabolites in symbiosis by mass spectrometry

• Marine Vallet,
• Filip Kaftan,
• Veit Grabe,
• Fatemeh Ghaderiardakani,
• Simona Fenizia,
• Aleš Svatoš,
• Georg Pohnert and
• Thomas Wichard

Beilstein J. Org. Chem. 2021, 17, 1313–1322, doi:10.3762/bjoc.17.91

• specialised metabolites involved in host–bacteria interactions. In our study, comparative metabolomics using atmospheric pressure scanning microprobe matrix-assisted laser desorption/ionisation high-resolution mass spectrometry (AP-SMALDI-HRMS) enables the identification of specialised metabolites of the

• intensities of the compounds of interest. In some cases, the matrix might also work in opposition to this premise, suppressing desired ions. Then, matrix-free approaches such as LDI-HRMS can overcome this limiting phenomenon and have been applied for species-level microalgal identification based on metabolic

• features m/z 104.1064 and m/z 143.0815 have only been detected by one of the two methods. Identification of metabolites in Ulva–bacteria symbiosis To identify the selected markers found by the comparative metabolomics study, we searched several mass spectra libraries, including METLIN, and determined the