Chemical and biosynthetic potential of Penicillium shentong XL-F41

• Ran Zou,
• Xin Li,
• Xiaochen Chen,
• Yue-Wei Guo and
• Baofu Xu

Beilstein J. Org. Chem. 2024, 20, 597–606, doi:10.3762/bjoc.20.52

• enzymatic ring-expansion process in their respective fungi. Both shentonins A (1) and B (2) also feature a reduction of a carbonyl to a hydroxy group within the succinimide ring. All isolated compounds were subjected to antimicrobial evaluations, and compound 12 was found to have moderate inhibitory

A myo-inositol dehydrogenase involved in aminocyclitol biosynthesis of hygromycin A

• Michael O. Akintubosun and
• Melanie A. Higgins

Beilstein J. Org. Chem. 2024, 20, 589–596, doi:10.3762/bjoc.20.51

• 584 sequences were near an acyl synthase domain, 340 sequences by an acyl carrier protein domain, and 1,193 sequences by a thioesterase domain. In addition, Hyg17 works together with the aminotransferase Hyg8 to replace a hydroxy group with an amine generating an aminocyclitol from myo-inositol. We

Recent developments in the engineered biosynthesis of fungal meroterpenoids

• Zhiyang Quan and
• Takayoshi Awakawa

Beilstein J. Org. Chem. 2024, 20, 578–588, doi:10.3762/bjoc.20.50

• meroterpenoids: insuetusin A1 (12) and insuetusin B1 (10), respectively (Figure 2) [9]. Like other Trt1-type enzymes, InsB2 catalyzes the protonation of the epoxide, the formation of two six-membered rings in a chair–chair conformation, but the reaction finishes with the deprotonation of the hydroxy group at C-3

• hydroxy group terminates the cyclization [20][21]. In ascofuranone biosynthesis, compound 21 is initially hydroxylated at C-8, and then the hydroxylated product is cyclized via epoxidation by AscI to form the tetrahydrofuran ring of 23. The biosynthetic pathways of 22 and 23 were elucidated through

Green and sustainable approaches for the Friedel–Crafts reaction between aldehydes and indoles

• Periklis X. Kolagkis,
• Eirini M. Galathri and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2024, 20, 379–426, doi:10.3762/bjoc.20.36

Elucidating the glycan-binding specificity and structure of Cucumis melo agglutinin, a new R-type lectin

• Jon Lundstrøm,
• Emilie Gillon,
• Valérie Chazalet,
• Nicole Kerekes,
• Antonio Di Maio,
• Ten Feizi,
• Yan Liu,
• Annabelle Varrot and
• Daniel Bojar

Beilstein J. Org. Chem. 2024, 20, 306–320, doi:10.3762/bjoc.20.31

• nitrogen. CH−π stacking and hydrophobic interactions occur between the aromatic ring of Trp36 and the alpha face of the ring as well as the hydroxymethyl moiety of the galactose residue, additionally ensuring specificity for galactoside over glucoside as an equatorial conformation of the O4 hydroxy group

Nucleophilic functionalization of thianthrenium salts under basic conditions

• Xinting Fan,
• Duo Zhang,
• Xiangchuan Xiu,
• Bin Xu,
• Yu Yuan,
• Feng Chen and
• Pan Gao

Beilstein J. Org. Chem. 2024, 20, 257–263, doi:10.3762/bjoc.20.26

• accessible and have significant importance in the pharmaceutical industry, positioning them as appealing candidates for C(sp3) coupling due to their availability as a common chemical feedstock. However, due to the high bond dissociation energy of the C–O bond and the poor leaving ability of the hydroxy group

Comparison of glycosyl donors: a supramer approach

• Anna V. Orlova,
• Nelly N. Malysheva,
• Maria V. Panova,
• Nikita M. Podvalnyy,
• Michael G. Medvedev and
• Leonid O. Kononov

Beilstein J. Org. Chem. 2024, 20, 181–192, doi:10.3762/bjoc.20.18

• sialylation of the primary hydroxy group of the same galactose derivative 3 [54] (see Scheme 1), which eventually led to unprecedented conclusions concerning the very possibility of comparison of chemical properties of different glycosyl donors. Results Synthesis of glycosyl donor 2 Sialyl donor 2 was

Tandem Hock and Friedel–Crafts reactions allowing an expedient synthesis of a cyclolignan-type scaffold

• Viktoria A. Ikonnikova,
• Cristina Cheibas,
• Oscar Gayraud,
• Alexandra E. Bosnidou,
• Nicolas Casaretto,
• Gilles Frison and
• Bastien Nay

Beilstein J. Org. Chem. 2024, 20, 162–169, doi:10.3762/bjoc.20.15

• methide intermediate 9 upon elimination of the hydroxy group. This highly electrophilic species could trigger a second intramolecular Friedel–Crafts reaction leading to 6. The cyclic connectivity of 6 was determined by bidimensional NMR experiments, incidentally showing a broadening of the signals of

Using the phospha-Michael reaction for making phosphonium phenolate zwitterions

• Matthias R. Steiner,
• Max Schmallegger,
• Larissa Donner,
• Johann A. Hlina,
• Christoph Marschner,
• Judith Baumgartner and
• Christian Slugovc

Beilstein J. Org. Chem. 2024, 20, 41–51, doi:10.3762/bjoc.20.6

• synthesis of carbonates from CO2 [24][25][26] and the synthesis of oxazolidines from isocyanates and epoxides [27]. Furthermore, their application in primary hydroxy group selective acylation of diols [28] and their use as organophotoredox catalysts [29][30] is known. The latter mentioned catalysts are

• acceptor methyl acrylate reacts much faster in chloroform than acrylonitrile. A likely explanation is the preorganization of the Michael acceptor and donor by hydrogen bonding between the phosphine’s hydroxy group and the carbonyl group of the ester B’. Such a preorganization facilitates the proton

• transfer [34] from the hydroxy group to the initial zwitterion via B’’ and B’’’ resulting in C. In this case, the proton at the α-position to the electron-withdrawing group is stemming from the phenol moiety. Methyl acrylate in methanol is the fastest reaction presumably because both pathways, the

Selectivity control towards CO versus H₂ for photo-driven CO₂ reduction with a novel Co(II) catalyst

• Lisa-Lou Gracia,
• Philip Henkel,
• Olaf Fuhr and
• Claudia Bizzarri

Beilstein J. Org. Chem. 2023, 19, 1766–1775, doi:10.3762/bjoc.19.129

• solvents and with water, it has been used in a large variety of (electro)chemical reactions [53]. The hydroxy group of this alcohol has a pKa of 9.3 [54][55], so we can expect that it is a suitable proton donor for this kind of reaction. We performed the photocatalytic CO2 reduction by dissolving in 5 mL 1

Trifluoromethylated hydrazones and acylhydrazones as potent nitrogen-containing fluorinated building blocks

• Zhang Dongxu

Beilstein J. Org. Chem. 2023, 19, 1741–1754, doi:10.3762/bjoc.19.127

• presence of Brønsted acid. In their pioneering research, Tanaka et al. reported the [3 + 2] cycloaddition reactions of trifluoroacetaldehyde hydrazones and glyoxals to give 4-hydroxy-3-trifluoromethylpyrazoles. The resultant pyrazoles containing a free 4-hydroxy group were easily converted to a variety of

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• phenolic hydroxy group and the azomethine nitrogen was identified in the solid state and seems to be maintained in solution. Moreover, the presence of the electron-withdrawing nitro substituent makes this interaction stronger. However, the contact should probably not subsist for the nitro compound under

• -substituent in the aldehyde-derived portion of hdz-NO2 caused a strong deshielding of the hydroxy group (assigned at 12.84 ppm) due to the removal of electron density on the carbon adjacent to –OH. On the other hand, in hdz-CH3, the presence of the methyl substituent moderately shields this proton (11.89 ppm

• ). A comparison of the H7 and –OH chemical shifts of the related hydrazones hdz-CH3 and hdz-NO2 indicates that, also in solution, the intramolecular H-bond is stronger in the latter. Since N-acylhydrazones may be susceptible to hydrolysis, especially those containing a hydroxy group in ortho-position

Synthesis of 5-arylidenerhodanines in L-proline-based deep eutectic solvent

• Stéphanie Hesse

Beilstein J. Org. Chem. 2023, 19, 1537–1544, doi:10.3762/bjoc.19.110

• hydroxy group showed DPPH radical scavenging activity. Compound 3d with a catechol-like structure exhibited the best antioxidant activity. Experimental General procedure for the Knoevenagel condensation DES (0.8 g) was introduced in a 10 mL round-bottomed flask. Then, the aldehyde (0.5 mmol) and rhodanine

Complexes of resorcin[4]arene with secondary amines: synthesis, solvent influence on “in-out” structure, and theoretical calculations of non-covalent interactions

• Waldemar Iwanek

Beilstein J. Org. Chem. 2023, 19, 1525–1536, doi:10.3762/bjoc.19.109

• transferred from the hydroxy group of R[4]A to the amine molecule, forming a hydrogen bond between the proton of the positively charged amino group and the oxygen anion in the R[4]A molecule (ArO−···H+NHR2). For sec-amine molecules such as morpholine and N-methylpiperazine, an “out” complex is formed by

• hydrogen bonding between the proton of the hydroxy group of R[4]A and the nitrogen atom of the amine molecule (ArOH···NHR2). In CHCl3, the amine molecule partially resides within the R[4]A cavity and the formed complex is stabilized by a hydrogen bond between the hydroxy group of R[4]A and the nitrogen

• hydrogen bond between the oxygen anion of the hydroxy group (which also forms a hydrogen bond with the amine molecule) and the adjacent hydroxy group in DMSO in the R[4]A (1.505 Å) molecule than the remaining intramolecular hydrogen bonds. In CHCl3, both the type and length of the hydrogen bond undergo

N-Sulfenylsuccinimide/phthalimide: an alternative sulfenylating reagent in organic transformations

• Fatemeh Doraghi,
• Seyedeh Pegah Aledavoud,
• Mehdi Ghanbarlou,
• Bagher Larijani and
• Mohammad Mahdavi

Beilstein J. Org. Chem. 2023, 19, 1471–1502, doi:10.3762/bjoc.19.106

• reactivity than electron-withdrawing groups, and the thiolation occurred mainly at the para position to the hydroxy group in phenols. In 2016, the azidoarylthiation of various alkenes 9 by trimethylsilyl azide (10) and N-(organothio)succinimide 1 to the corresponding products containing ortho-sited azide and

Cyclization of 1-aryl-4,4,4-trichlorobut-2-en-1-ones into 3-trichloromethylindan-1-ones in triflic acid

• Vladislav A. Sokolov,
• Andrei A. Golushko,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2023, 19, 1460–1470, doi:10.3762/bjoc.19.105

• that the formation of dications D does not take place. Species B should be the key reactive intermediates that undergo cyclization into indanones 3 with a negative Gibbs energy of −7 kJ/mol for the reaction Ba→3a. According to the calculations, the subsequent complete protonation of the hydroxy group

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• -naphthol moiety 193 afforded the highest yield and enantioselectivity. On protecting the hydroxy group in the ligand as methyl ether, the reaction efficiency decreased remarkably. However, on using NHC ligands without oxygen atom, such as analogues of 193, IMes, and SIMes, no conversion occurred. 2.8 C(sp2

One-pot nucleophilic substitution–double click reactions of biazides leading to functionalized bis(1,2,3-triazole) derivatives

• Hans-Ulrich Reissig and
• Fei Yu

Beilstein J. Org. Chem. 2023, 19, 1399–1407, doi:10.3762/bjoc.19.101

• led to the expected bis(1,2,3-triazoles) 20 or 21 in moderate or very good yield (Scheme 6). We cannot decide whether the lower yields in this series are caused by the unprotected hydroxy group of precursor 19 or the corresponding products. Although we did not isolate the conceivable mono-adducts we

• cannot rigorously exclude their formation. Compared to bis(1,2,3-triazoles) 14 and 17, compounds 20 and 21 are one step closer to the desired divalent aminopyran-substituted carbohydrate mimetics, since they already contain a free hydroxy group instead of the carbonyl group. However, their reductive

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

• using the PCl3 method. Then, the benzoyl protecting group was removed (89%) and the hydroxy group at the sn-2 position was esterified with acetic anhydride (94%) to produce oleyl-PAF 9.7. Different modifications involved the sn-1 position of the glycerol moiety. In 1984, Wissner et al., reported the

Metal catalyst-free N-allylation/alkylation of imidazole and benzimidazole with Morita–Baylis–Hillman (MBH) alcohols and acetates

• Olfa Mhasni,
• Jalloul Bouajila and
• Farhat Rezgui

Beilstein J. Org. Chem. 2023, 19, 1251–1258, doi:10.3762/bjoc.19.93

• precursors in nucleophilic allylic substitution reactions with amines, presumably due to the perceived poor leaving group ability and low reactivity of the hydroxy group. Interestingly, the direct nucleophilic substitution of the corresponding alcohols has drawn much attention because of the availability of

Two new lanostanoid glycosides isolated from a Kenyan polypore Fomitopsis carnea

• Winnie Chemutai Sum,
• Sherif S. Ebada,
• Didsanutda Gonkhom,
• Cony Decock,
• Rémy Bertrand Teponno,
• Josphat Clement Matasyoh and
• Marc Stadler

Beilstein J. Org. Chem. 2023, 19, 1161–1169, doi:10.3762/bjoc.19.84

• system in the 1H,1H COSY spectrum (Figure 2) with a methylene group at δH 1.51/δH 1.73 (H2-1) and a methine proton at δH 4.96 (H-3). These results suggested that compound 2 features a hydroxy group at C-2 rather than a methylene group as in forpinioside B (1). Further confirmation for the suggested

• position of the hydroxy group at C-2 was provided by the HMBC spectrum (Figure 2) which exhibited clear correlations from H-2 to four carbon resonances at δC 40.7 (C-1), 81.8 (C-3), 39.0 (C-4), and 39.5 (C-10). Aside from this difference and by comparing the 1D and 2D NMR spectral data of compounds 1 and 2

• (L929) (IC50 = 15.2 µM), breast cancer cells (MCF-7) (17.6 µM), and prostate cancer cells (PC-3) (18.9 µM). Discussion The introduction of a hydroxy group at C-2 rendered forpinioside C (2) inactive in antimicrobial assays compared to forpinioside B (1), however; both compounds were not active in the

Linker, loading, and reaction scale influence automated glycan assembly

• Marlene C. S. Dal Colle,
• Manuel G. Ricardo,
• Nives Hribernik,
• José Danglad-Flores,
• Peter H. Seeberger and
• Martina Delbianco

Beilstein J. Org. Chem. 2023, 19, 1015–1020, doi:10.3762/bjoc.19.77

• ] and L2 [3] are based on the o-nitrobenzyl scaffold [23][24] and expose a hydroxy group that serves as glycosyl acceptor in the first AGA cycle (Figure 1B). While L1 displays a flexible aliphatic chain terminating with a primary alcohol, L2 carries a secondary benzylic alcohol. Upon irradiation with UV

Aromatic C–H bond functionalization through organocatalyzed asymmetric intermolecular aza-Friedel–Crafts reaction: a recent update

• Anup Biswas

Beilstein J. Org. Chem. 2023, 19, 956–981, doi:10.3762/bjoc.19.72

• -derived ketimines 49 was reported by Vila, Pedro and co-workers. Regioisomeric hydroxyquinolines were tested in this reaction to facilitate the electrophilic aromatic substitution on the ortho-carbon atom with respect to the hydroxy group in quinolines 15. The reaction affords oxindole scaffolds 116 with

Intermediates and shunt products of massiliachelin biosynthesis in Massilia sp. NR 4-1

• Till Steinmetz,
• Blaise Kimbadi Lombe and
• Markus Nett

Beilstein J. Org. Chem. 2023, 19, 909–917, doi:10.3762/bjoc.19.69

• position. An HMBC correlation from H-4 to the carbon atom at 32.7 ppm (C-7) allowed the linkage of the phenol moiety with an n-pentyl sidechain in meta position to the hydroxy group. The spin system of the latter includes proton resonances at δH 2.54 (H-7a), 2.62 (H-7b), 1.49 (H-8), 1.25 (H-9), 1.25 (H-10

First synthesis of acylated nitrocyclopropanes

• Kento Iwai,
• Rikiya Kamidate,
• Khimiya Wada,
• Haruyasu Asahara and
• Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2023, 19, 892–900, doi:10.3762/bjoc.19.67

• the enol form, a C-attack (path a) furnishes cyclopropane 1, and an O-attack (path b) furnishes dihydrofuran 8. When the R1 group becomes bulkier, the hydroxy group may be far from the reaction site because of the steric repulsion in the stable conformation. Another possibility is that the bulky