Photoredox-catalyzed intramolecular nucleophilic amidation of alkenes with β-lactams

• Valentina Giraldi,
• Giandomenico Magagnano,
• Daria Giacomini,
• Pier Giorgio Cozzi and
• Andrea Gualandi

Beilstein J. Org. Chem. 2024, 20, 2461–2468, doi:10.3762/bjoc.20.210

• reaction was carried out in DCM with acridinium PC IV (5 mol %), 50 mol % of PhSSPh as HAT catalyst, and lutidine (50 mol %) as the base. Upon 72 hours of irradiation with a blue light at 456 nm, the product 11c was obtained in a satisfactory yield as a mixture of diastereoisomers in a 1.4:1 ratio (Table 1

Evaluating the halogen bonding strength of a iodoloisoxazolium(III) salt

• Dominik L. Reinhard,
• Anna Schmidt,
• Marc Sons,
• Julian Wolf,
• Elric Engelage and
• Stefan M. Huber

Beilstein J. Org. Chem. 2024, 20, 2401–2407, doi:10.3762/bjoc.20.204

• ). Halogen bonding dimer found in the crystal structure of 7Br. Ellipsoids are shown at 50% probability (carbon: grey, nitrogen: blue, oxygen: red, bromine: orange, iodine: purple) and hydrogen atoms are shown in standard ball-and-stick model (white). Halogen and hydrogen bonding is indicated dashed. 1H NMR

Improved deconvolution of natural products’ protein targets using diagnostic ions from chemical proteomics linkers

• Andreas Wiest and
• Pavel Kielkowski

Beilstein J. Org. Chem. 2024, 20, 2323–2341, doi:10.3762/bjoc.20.199

• field have the potential to facilitate this advancement. Overall chemical proteomics strategy to identify protein targets of natural products (NPs) and similar active small compounds. The example protein (blue) is an AlphaFold v2.0-generated prediction of bovine serum albumin (BSA) [23][24]. A) Design

Hydrogen-bond activation enables aziridination of unactivated olefins with simple iminoiodinanes

• Phong Thai,
• Lauv Patel,
• Diyasha Manna and
• David C. Powers

Beilstein J. Org. Chem. 2024, 20, 2305–2312, doi:10.3762/bjoc.20.197

• (denoted by asterisk *) of HFIP in the presence of iminoiodinane 2c suggesting hydrogen bonding observed in 1H NMR spectra (CD3CN) of: 8.0 mM 2c with no HFIP (blue line), 8.0 mM 2c with 32 mM HFIP (green line), 4.0 mM of 4-(trifluoromethyl)benzenesulfonamide with 32 mM HFIP (purple line), only 32 mM HFIP

• (red line). b) Cyclic voltammogram of iminoiodinane 2c (8.0 mM) with varying amounts of HFIP in 5.0 mL solution of MeCN (0.10 M TBABF4) under N2 atmosphere: 2c with no HFIP (black line); 2c with 5, 10, 15 µL HFIP (grey line); 2c with 25 µL HFIP (red line); only 25 µL (blue line). c) Diastereomeric

Metal-free double azide addition to strained alkynes of an octadehydrodibenzo[12]annulene derivative with electron-withdrawing substituents

• Naoki Takeda,
• Shuichi Akasaka,
• Susumu Kawauchi and
• Tsuyoshi Michinobu

Beilstein J. Org. Chem. 2024, 20, 2234–2241, doi:10.3762/bjoc.20.191

• profiles (ΔG298 in kJ mol−1) calculated at the ωB97X-D/6-31G(d,p)/PCM (in CH2Cl2). Absorption (blue) and fluorescence (red) spectra of 6a (2 × 10−5 M) in CH2Cl2. (a) Crosslinking reaction of PVC-N3 (x = 0.11) with compound 5. (b,c) Strain-stress curves of PVC-N3 before (blue) and after (red) crosslinking

Finding the most potent compounds using active learning on molecular pairs

• Zachary Fralish and
• Daniel Reker

Beilstein J. Org. Chem. 2024, 20, 2152–2162, doi:10.3762/bjoc.20.185

• shown in the inlet with a green bar while the times it ‘stays’ in the same cluster is shown with a light blue bar. Arrow gradient towards darker grey indicates increasing iteration number. Tree-based model navigation of chemical space. T-SNE of a representative dataset (CHEMBL232-1, Alpha-1b adrenergic

• another is shown in the inlet with a green bar while the times it ‘stays’ in the same cluster is shown with a light blue bar. Arrow gradient towards darker grey indicates increasing iteration number. Supporting Information Supporting Information File 54: Supplementary figures and tables

Efficacy of radical reactions of isocyanides with heteroatom radicals in organic synthesis

• Akiya Ogawa and
• Yuki Yamamoto

Beilstein J. Org. Chem. 2024, 20, 2114–2128, doi:10.3762/bjoc.20.182

• quinoxaline synthesis was reported to proceed by irradiation with visible light in the presence of dibenzylamine ((PhCH2)2NH, MeCN, rt, blue LED) [64]. This reaction involves a visible-light-induced single electron transfer (SET) process. An efficient radical cascade cyclization has also been reported, in

Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps

• Ignaz Betcke,
• Alissa C. Götzinger,
• Maryna M. Kornet and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178

• synthesized 4 halopyrazoles 111 and their Suzuki products 110 fluoresce blue in solution and have quantum yields of 29–72 % (Scheme 40) [137]. The Suzuki coupling can also be used for the functionalization of pyrazoles. For this purpose, p-bromo-substituted terminal alkynes 112, acyl chlorides 114, and

• pathway enables the synthesis of 3,5-bis(biphenyl)-1-methyl pyrazole. To stabilize the catalyst, additional triphenylphosphane is added as a ligand during the Suzuki coupling. The resulting products fluoresce blue, with the five biaryl-substituted derivatives 113 showing the highest quantum yields of up

Understanding X-ray-induced isomerisation in photoswitchable surfactant assemblies

• Beatrice E. Jones,
• Camille Blayo,
• Jake L. Greenfield,
• Matthew J. Fuchter,
• Nathan Cowieson and
• Rachel C. Evans

Beilstein J. Org. Chem. 2024, 20, 2005–2015, doi:10.3762/bjoc.20.176

• ) that contains mostly Z isomers. This can be reversed using blue light or heat in a process that is stable over many cycles [7]. Isomerisation of azobenzene leads to a change in its conformation and polarity which, when combined into a surfactant molecule, modifies the resulting molecular geometry and

• on their own and in mixed micelles with lipids, on irradiation with either UV or blue light [21][22]. In addition, Ober et al. showed that in-situ UV irradiation stimulates a steady decrease in bilayer thickness for vesicles formed using Azo-modified phosphatidylcholine lipids, due to the shorter

• pattern to that of the native, E isomer (Figure 2). Changes occur immediately, after 1 s of X-ray exposure, and saturate after ca. 5 s. The changes are comparable to those observed on Z–E isomerisation induced using blue (460 nm) light or heating to 55 °C but occur at a much faster rate (Figure S2

Development of a flow photochemical process for a π-Lewis acidic metal-catalyzed cyclization/radical addition sequence: in situ-generated 2-benzopyrylium as photoredox catalyst and reactive intermediate

• Masahiro Terada,
• Zen Iwasaki,
• Ryohei Yazaki,
• Shigenobu Umemiya and
• Jun Kikuchi

Beilstein J. Org. Chem. 2024, 20, 1973–1980, doi:10.3762/bjoc.20.173

• 2a, and 0.5 mmol (5 equiv) of TFA under light irradiation (blue LED: λmax = 448 nm) at 50 °C for 1 h in 1 mL (total volume) of 1,2-DCE] [55] with a flow rate of 3 mL/h (light irradiation time: 20 min in the flow reaction, 1 h in the batch reaction). As shown in Table 1, product 3a was obtained in

Negishi-coupling-enabled synthesis of α-heteroaryl-α-amino acid building blocks for DNA-encoded chemical library applications

• Matteo Gasparetto,
• Balázs Fődi and
• Gellért Sipos

Beilstein J. Org. Chem. 2024, 20, 1922–1932, doi:10.3762/bjoc.20.168

• Negishi reaction (Supporting Information File 1). Preliminary experiments were carried out with and without blue light irradiation in the PhotoCubeTM photoreactor [45]. These experiments revealed that while the conversion of imidazoles and pyrazoles benefits from irradiation, thiazoles seem to be largely

• within 4 h in the dark, irradiation with blue light halves the reaction time for many compounds. Overall, these observations are in line with those of Alcazar et al. [43]. In their work, the authors demonstrated the formation of a complex between palladium and the organozinc reagent which is absorbing in

• the blue region. This complex then accelerates the oxidative addition of the aryl halide to the metal, which is usually the rate-limiting step for palladium-catalyzed cross-couplings. Based on these results we decided to perform all Negishi reactions under blue light irradiation. With the optimized

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

• Cristina Martini,
• Muhammad Idham Darussalam Mardjan and
• Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

Hetero-polycyclic aromatic systems: A data-driven investigation of structure–property relationships

• Sabyasachi Chakraborty,
• Eduardo Mayo Yanes and
• Renana Gershoni-Poranne

Beilstein J. Org. Chem. 2024, 20, 1817–1830, doi:10.3762/bjoc.20.160

• distribution of the COMPAS-1 molecules (light blue) is contained within the distribution of the COMPAS-2 molecules (purple). In other words, the expansion of the building block library widens the property distributions towards both higher and lower energies, providing access to functional molecules with

• molecular properties. Comparison between COMPAS-1 (blue) and COMPAS-2 (purple). A) Principal Moments of Inertia shape distribution, all molecules sorted according to their normalized principal moments of inertia (In, n = 1–3), with I1 < I2 < I3. B) Molecular properties (all reported in eV): HOMO, LUMO, AIP

Discovery of antimicrobial peptides clostrisin and cellulosin from Clostridium: insights into their structures, co-localized biosynthetic gene clusters, and antibiotic activity

• Moisés Alejandro Alejo Hernandez,
• Katia Pamela Villavicencio Sánchez,
• Rosendo Sánchez Morales,
• Karla Georgina Hernández-Magro Gil,
• David Silverio Moreno-Gutiérrez,
• Eddie Guillermo Sanchez-Rueda,
• Yanet Teresa-Cruz,
• Brian Choi,
• Armando Hernández Garcia,
• Alba Romero-Rodríguez,
• Oscar Juárez,
• Siseth Martínez-Caballero,
• Mario Figueroa and
• Corina-Diana Ceapă

Beilstein J. Org. Chem. 2024, 20, 1800–1816, doi:10.3762/bjoc.20.159

• presented (right). The highlighted cluster was chosen for heterologous expression. A. Similarity network created with the ESI web tool with the precursor peptide amino acid sequences. In the similarity network of precursor peptides, each blue node represents a characterized lanthipeptide, and each pink node

Oxidative fluorination with Selectfluor: A convenient procedure for preparing hypervalent iodine(V) fluorides

• Samuel M. G. Dearman,
• Xiang Li,
• Yang Li,
• Kuldip Singh and
• Alison M. Stuart

Beilstein J. Org. Chem. 2024, 20, 1785–1793, doi:10.3762/bjoc.20.157

• (blue line), dry CDCl3 with 2.4 equivalents of dry pyridine (green line), and dry CDCl3 (red line). Order of hydrolytic stability for the four hypervalent iodine(V) fluorides. Examples of fluorination using hypervalent iodine(III) reagents 1 and 2. Preparations and reactions of hypervalent iodine(V

Synthesis and characterization of 1,2,3,4-naphthalene and anthracene diimides

• Adam D. Bass,
• Daniela Castellanos,
• Xavier A. Calicdan and
• Dennis D. Cao

Beilstein J. Org. Chem. 2024, 20, 1767–1772, doi:10.3762/bjoc.20.155

• = green, N = blue, and O = red. a) Absorption and b) emission spectra of the compounds dissolved in CH2Cl2. Cyclic voltammograms of the compounds collected on ca. 1 mM solutions of the analyte in CH2Cl2 with 0.1 M Bu4NPF6 as electrolyte. The major y-axis tick mark spacing corresponds to 5 μA. Structural

Syntheses and medicinal chemistry of spiro heterocyclic steroids

• Laura L. Romero-Hernández,
• Ana Isabel Ahuja-Casarín,
• Penélope Merino-Montiel,
• Sara Montiel-Smith,
• José Luis Vega-Báez and
• Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

• C–H insertion to produce the spiro-β-lactone was accomplished by simply exposing the diazo derivative to 440 nm blue LEDs (Kessil lamp) at 50 °C, that favored the formation of a singlet carbene that reacted selectively by insertion into the C(3)–H bond. Spiro-lactones 14 were obtained in 80% yield

Oxidation of benzylic alcohols to carbonyls using N-heterocyclic stabilized λ³-iodanes

• Thomas J. Kuczmera,
• Pim Puylaert and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2024, 20, 1677–1683, doi:10.3762/bjoc.20.149

• formation of a) an alkoxy-NHI which is causing a significant downfield shift of the protons in alpha-position (orange) compared to the free alcohol 2 (blue) and b) oxidation of p-tolylmethanol (3a, blue) to the aldehyde 4a (green) and carboxylic acid 4a’ (red). Reaction conditions: An equimolar mixture of

Methyltransferases from RiPP pathways: shaping the landscape of natural product chemistry

• Maria-Paula Schröder,
• Isabel P.-M. Pfeiffer and
• Silja Mordhorst

Beilstein J. Org. Chem. 2024, 20, 1652–1670, doi:10.3762/bjoc.20.147

• /aspartimide to isoaspartate. The methyl group is highlighted in blue. The reverse reaction with isoaspartate as substrate of PAMTs is also known. Structural organisation of the OphMA homodimer. A) Schematic representation. The MT domain is coloured in blue; the leader peptide is coloured in yellow, and the

Generation of multimillion chemical space based on the parallel Groebke–Blackburn–Bienaymé reaction

• Evgen V. Govor,
• Vasyl Naumchyk,
• Ihor Nestorak,
• Dmytro S. Radchenko,
• Dmytro Dudenko,
• Yurii S. Moroz,
• Olexiy D. Kachkovsky and
• Oleksandr O. Grygorenko

Beilstein J. Org. Chem. 2024, 20, 1604–1613, doi:10.3762/bjoc.20.143

• molecules to be similar. In this way, data visualization becomes possible since similar molecules will likely have close values of t-SNE1 and t-SNE2. As apparent from Figure 7, there is a small overlap between the GBB chemical space (yellow datapoints) with all four databases of comparison (blue data points

• count; F(sp3) – fraction of sp3-hybrid carbon atoms; RotB – rotatable bond count); compounds complying with specific Lipinski/Veber rules (MW ≤ 500, log P ≤ 5, HDon ≤ 5, HAcc ≤ 10, RotB ≤ 10 [38][41]) as well as compounds with F(sp3) > 0.5 are highlighted in blue, the rest of the compounds are shown in

Supramolecular assemblies of amphiphilic donor–acceptor Stenhouse adducts as macroscopic soft scaffolds

• Ka-Lung Hung,
• Leong-Hung Cheung,
• Yikun Ren,
• Ming-Hin Chau,
• Yan-Yi Lam,
• Takashi Kajitani and
• Franco King-Chi Leung

Beilstein J. Org. Chem. 2024, 20, 1590–1603, doi:10.3762/bjoc.20.142

• -DA11 (Figure 1a, black line and Figure 1b blue line) to the cyclized-isomer C-DA11 (Figure 1a, red line). The resulting solution continued to be irradiate with 625 nm red light for 60 s at 20 °C and subsequently stored in the dark at 20 °C for 60 min for the thermal back reaction to occur to test the

•  1d and Figure 1f, blue line), the strong absorption band had recovered and indicated a selective photoisomerization process from the open-isomers O-DA7 and O-DA6 (Figure 1c–f, black and blue lines) to the cyclized-isomers C-DA7 and C-DA6 (Figure 1d and Figure 1f, red line). The results showed

• used for the fabrication of macroscopic soft scaffolds after charge screening with complementary ions. Fabrication and characterization of macroscopic soft scaffolds of DAn in aqueous medium A freshly prepared aqueous solution of DA11 (5.0 wt %, 82 mM) was deep blue and remained stable for months. By

Mining raw plant transcriptomic data for new cyclopeptide alkaloids

• Draco Kriger,
• Michael A. Pasquale,
• Brigitte G. Ampolini and
• Jonathan R. Chekan

Beilstein J. Org. Chem. 2024, 20, 1548–1559, doi:10.3762/bjoc.20.138

• . The bar graphs show the number of average unique transcripts from each plant species. Producers are indicated with an orange or blue dot. Weblogos generated with aligned recognition and core sequences from the six different families discussed. Up to three unique sequences were taken from each assembly

• , blue arrows – HMBC. Peptide modifications are shown in purple. A) Precursor peptide sequences found in the transcriptome of G. jasminoides containing the cores FFFY, IFLY, and LFLY. A) GJA649 gene cluster from G. jasminoides. Core sequences from the putative precursor peptides map to three predicted

Benzylic C(sp³)–H fluorination

• Alexander P. Atkins,
• Alice C. Dean and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137

• ]. Photoexcitation of the Ir(III) catalyst I with blue light resulted in the photoexcited Ir(III)* catalyst, which was capable of performing a single-electron reduction on N-acyloxyphthalimide, promoting decarboxylation, releasing CO2, a methyl radical, anionic phthalimide and an Ir(IV) species. The resultant methyl

• -catalysed bidentate-directed benzylic C(sp3)–H fluorination. Palladium-catalysed benzylic fluorination using a transient directing group approach. Ratio refers to fluorination (red) vs oxygenation (blue) product. Outline for benzylic C(sp3)–H fluorination via radical intermediates. Iron(II)-catalysed

Photoswitchable glycoligands targeting Pseudomonas aeruginosa LecA

• Yu Fan,
• Ahmed El Rhaz,
• Stéphane Maisonneuve,
• Emilie Gillon,
• Maha Fatthalla,
• Franck Le Bideau,
• Guillaume Laurent,
• Samir Messaoudi,
• Anne Imberty and
• Juan Xie

Beilstein J. Org. Chem. 2024, 20, 1486–1496, doi:10.3762/bjoc.20.132

• decreases concomitantly to the appearance of two new bands at 312 and 438 nm (Figure 2, blue line). Two isosbestic points can also be observed at 310 and 429 nm. The back Z→E photoisomerization can be achieved by illumination at 485 nm (Figure 2, red line). 1H NMR spectroscopy has been used to determine the

•  1). All the photophysical properties of compounds 1–5 are summarized in Table 1 (spectra are shown in Figure S1–S24 in Supporting Information File 1). Concerning the meta-substituted azobenzene 2, a 30 nm blue shift is observed for the π→π* transition (λmax = 321 nm) as well as a lower absorption

• ) designed general structure of photoswitchable ligands 1–5 targeting LecA. (Left) Absorption spectra and (right) fatigue resistance of 1 under alternated 370/485 nm irradiations in Tris buffer/DMSO 95:5 at rt: E-1 (black line), PSS370 (blue line), PSS485 (red line). Irradiation conditions at 370 nm: 12.8

Bioinformatic prediction of the stereoselectivity of modular polyketide synthase: an update of the sequence motifs in ketoreductase domain

• Changjun Xiang,
• Shunyu Yao,
• Ruoyu Wang and
• Lihan Zhang

Beilstein J. Org. Chem. 2024, 20, 1476–1485, doi:10.3762/bjoc.20.131

• classification of their products. The key catalytic residues are marked by red stars, and the NADPH-binding residues (partially) are marked by blue triangles. The numbers at the top indicate the fingerprint motifs. Sequence logo comparation of γ- and δ-module KRC based on the classification of their products

• . Top five rows show KRs associated with an inactive DH that produces the hydroxy products. The key catalytic residues are marked by red stars, and the NADPH-binding residues (partially) are marked by blue triangles. The motif numbers at the top are corresponding to the location of fingerprints in