Anomeric 1,2,3-triazole-linked sialic acid derivatives show selective inhibition towards a bacterial neuraminidase over a trypanosome trans-sialidase

• Peterson de Andrade,
• Sanaz Ahmadipour and
• Robert A. Field

Beilstein J. Org. Chem. 2022, 18, 208–216, doi:10.3762/bjoc.18.24

• ) and compounds were visualised by UV irradiation (λ = 254 nm) and/or dipping in ethanol/sulfuric acid (95:5 v/v) followed by heating. A Biotage SP4 flash chromatography system was used for purification of the protected sugars with normal phase silica (pre-packed SNAP Ultra cartridges). Deprotected

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

• using 95% aqueous ethanol (15 L × 4 times × 2 h at room temperature) with ultrasonic assistance. The combined extracts were filtered and evaporated under reduced pressure to yield a green residue (350.6 g). The crude extract was suspended in distilled H2O (2 L) and successively partitioned with n-BuOH

Green synthesis of C5–C6-unsubstituted 1,4-DHP scaffolds using an efficient Ni–chitosan nanocatalyst under ultrasonic conditions

• Soumyadip Basu,
• Sauvik Chatterjee,
• Suman Ray,
• Suvendu Maity,
• Prasanta Ghosh,
• Asim Bhaumik and
• Chhanda Mukhopadhyay

Beilstein J. Org. Chem. 2022, 18, 133–142, doi:10.3762/bjoc.18.14

• . We mainly focused on the synthesis under green aspects and towards a high product diversity. We initially chose three green solvents with a relatively low boiling point, ethanol, water, and acetone, respectively, as a reaction medium. A series of reactions was examined in these solvents, using an

• temperature. In the ultrasonication procedure, the reaction was started at room temperature, and after completion of the reaction, the final temperature of the solution was found to be 40 °C. Among the solvents, ethanol afforded the highest yield under sonication within a very short reaction time. When we

• further increasing this quantity did not result in an enhanced yield. As such, the optimized conditions were sonication for 15 min in ethanol using 30 mg of the Ni–chitosan NPs (Table 2, entry 17). The optimization studies using this standard amount of catalyst are summarized in Table 2. Substrate scope

Mechanistic studies of the solvolysis of alkanesulfonyl and arenesulfonyl halides

• Malcolm J. D’Souza and
• Dennis N. Kevill

Beilstein J. Org. Chem. 2022, 18, 120–132, doi:10.3762/bjoc.18.13

• -methyl derivative, 0.0146 min−1 for the parent compound, and 0.044 min−1 for the m-NO2 derivative. A change of solvent to 47.5% ethanol/52.5% water led to very similar behavior with the corresponding specific rates being 0.0287, 0.0313, and 0.058 min−1. In modern terminology, this would suggest a close

• value of +0.82 for the para-methyl derivative and of +0.71 for the meta-nitro derivative. and, for the study in 47.5% ethanol/52.5% water the corresponding values are +0.22 and +0.38, respectively. These small reaction constant ρ values depend only on the type of reaction but not on the substituent used

• aqueous dioxane, aqueous acetone, methanol/acetone, and ethanol/acetone, the p-NO2 (strongest electron-withdrawing influence) was always reacting faster than the parent and the other two derivatives and the overall behavior in a Hammett equation treatment indicated that all were reacting by an SN2 pathway

Efficient and regioselective synthesis of dihydroxy-substituted 2-aminocyclooctane-1-carboxylic acid and its bicyclic derivatives

• İlknur Polat,
• Selçuk Eşsiz,
• Uğur Bozkaya and
• Emine Salamci

Beilstein J. Org. Chem. 2022, 18, 77–85, doi:10.3762/bjoc.18.7

• material in the synthesis of the other isomer of β-amino acid 6. The ring-opening reaction of 7 with HCl(g) in MeOH resulted in a mixture of products 8 and 9 in a 9:1 ratio (1H NMR). The product 8 in the reaction mixture was purified by recrystallization from ethanol/ether, but all attempts to purify the

1,2-Naphthoquinone-4-sulfonic acid salts in organic synthesis

• Ruan Carlos B. Ribeiro,
• Patricia G. Ferreira,
• Amanda de A. Borges,
• Luana da S. M. Forezi,
• Fernando de Carvalho da Silva and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 53–69, doi:10.3762/bjoc.18.5

• reacted with different amines 42a–c in the presence of an ethanol–water mixture under ultrasonication, followed by reaction with arylhydrazines, which led to hydrazones 44a–l according to the classical procedure that employs methanol at room temperature. All compounds were evaluated against different

• methylene acid compounds [109]. These authors developed two methods (A and B) to prepare 2-hydroxynaphthoquinomethanes 62 with diverse structures by condensation of 18 with active methylene compounds (Scheme 18). Method A involves the reaction promoted by sodium hydroxide in an ethanol/water mixture at 40

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

• Pd source together with the water-soluble Buchwald ligand sulfonated SPhos (sSPhos) and potassium fluoride as a base. The reaction was performed in a solvent mixture of dimethoxyethane, ethanol and water (DME/EtOH/H2O 9:9:2) at 120 °C under microwave irradiation for 30 min (Scheme 1) [78]. The

Photophysical, photostability, and ROS generation properties of new trifluoromethylated quinoline-phenol Schiff bases

• Inaiá O. Rocha,
• Yuri G. Kappenberg,
• Wilian C. Rosa,
• Clarissa P. Frizzo,
• Nilo Zanatta,
• Marcos A. P. Martins,
• Isadora Tisoco,
• Bernardo A. Iglesias and
• Helio G. Bonacorso

Beilstein J. Org. Chem. 2021, 17, 2799–2811, doi:10.3762/bjoc.17.191

• using an equimolar ratio of both reactants in methanol, ethanol, and acetonitrile as solvent at reflux temperature according to previously reported data [22][24][25]. Thus, we found increasing yields for 3ba depending on the solvent used, i.e., 70% (methanol), 80% (ethanol), and 83% (acetonitrile

• after recrystallization from ethanol (Scheme 2). In order to evaluate the properties related to the substituents of the portion provided by salicylaldehyde, the same optimized conditions were applied to the reaction of quinoline 1b (R = C6H5) with various salicylaldehydes 2b–e, resulting in four more

• Schiff bases 3bb–be with 40–89% yield for the isolated products after recrystallization from ethanol (Scheme 3). With some exceptions, electron-deficient or electron-rich substituted 2-aryl-6-aminoquinolines and aromatic aldehydes worked very well to furnish the Schiff bases 3. However, a poor yield (20

Synthetic strategies toward 1,3-oxathiolane nucleoside analogues

• Umesh P. Aher,
• Dhananjai Srivastava,
• Girij P. Singh and
• Jayashree B. S

Beilstein J. Org. Chem. 2021, 17, 2680–2715, doi:10.3762/bjoc.17.182

• intermediate 37 was resolved using a lipase in t-BuOMe, resulting in a high enantiomeric excess. They used an enzymatic resolution of an acetoxy sulfide with a Pseudomonas fluorescens lipase to obtain compound 38. Reaction of chiral acetoxy sulfide 38 with HCl in dry ethanol induced acetate removal by

• synthesis of lamivudine (1) and the opposite enantiomer 1a was demonstrated by Han et al. [57]. They carried out the [1,2]-Brook rearrangement of silyl glyoxylate 61 using thiol 3nb as the nucleophile. Under optimized conditions, the reaction of the key intermediate 62 with acetyl chloride in ethanol

• directly with the presilylated cytosine without any promoter or additive and gave nucleoside 93 in a selective manner (β/α 10:1). The ester group of nucleoside derivative 93 was further reduced with sodium borohydride in ethanol, which gave lamivudine (1). An efficient and enantioselective synthesis of

Cryogels: recent applications in 3D-bioprinting, injectable cryogels, drug delivery, and wound healing

• Luke O. Jones,
• Leah Williams,
• Tasmin Boam,
• Martin Kalmet,
• Chidubem Oguike and
• Fiona L. Hatton

Beilstein J. Org. Chem. 2021, 17, 2553–2569, doi:10.3762/bjoc.17.171

• antibacterial properties as well [113]. Physically crosslinked chitosan-gluconic acid cryogels have also been reported by Takei et al., who investigated applying differing methods of sterilisation, using either ethanol washing [114], or by autoclaving the cryogels [115]. Interestingly, the cryogels retained

• their haemostatic properties following autoclaving at 121 °C for 20 min, and showed comparable healing rates compared to ethanol sterilisation (Figure 8). A unique take to the development of cryogels as injectable gels is the work achieved by Zhao et al. in developing an injectable antibacterial and

Silica gel and microwave-promoted synthesis of dihydropyrrolizines and tetrahydroindolizines from enaminones

• Robin Klintworth,
• Garreth L. Morgans,
• Stefania M. Scalzullo,
• Charles B. de Koning,
• Willem A. L. van Otterlo and
• Joseph P. Michael

Beilstein J. Org. Chem. 2021, 17, 2543–2552, doi:10.3762/bjoc.17.170

• . Yields of the bicyclic products were generally above 75%. The analogous microwave-assisted reaction to produce ethyl 2-aryl-5,6,7,8-tetrahydroindolizine-3-carboxylates from (E)-ethyl 2-[2-(2-oxo-2-arylethylidene)piperidin-1-yl]acetates failed in nonpolar solvents, but occurred in ethanol at lower

• 15a was heated in capped tubes under microwave conditions [35][36][37] for 10 minutes in solvents such as ethanol (100 °C), xylene (150 °C) or N,N-dimethylformamide (150 °C) (Table 1, entries 3–5). Dissolution in neat protic or Lewis acids (e.g., hydrochloric acid, trifluoroacetic acid

• site in accordance with well-established precedents [38][39]; and after ten minutes it could be recovered after neutralization with aqueous sodium hydrogen carbonate (Table 1, entries 6, 10). No apparent reaction occurred with dilute hydrochloric acid in ethanol (Table 1, entry 14) unless the solution

Visible-light-mediated copper photocatalysis for organic syntheses

• Yajing Zhang,
• Qian Wang,
• Zongsheng Yan,
• Donglai Ma and
• Yuguang Zheng

Beilstein J. Org. Chem. 2021, 17, 2520–2542, doi:10.3762/bjoc.17.169

• photoinduced copper-catalyzed α-C(sp3)–H cyclization of aliphatic alcohols with o-aminobenzamide. However, the aliphatic alcohols were limited to methanol and ethanol. In this transformation, α-C(sp3)–H of MeOH/EtOH undergoes a hydrogen atom transfer (HAT) process to synthesize quinazolinones involving ligand

Synthesis of new substituted 7,12-dihydro-6,12-methanodibenzo[c,f]azocine-5-carboxylic acids containing a tetracyclic tetrahydroisoquinoline core structure

• Agnieszka Grajewska,
• Maria Chrzanowska and
• Wiktoria Adamska

Beilstein J. Org. Chem. 2021, 17, 2511–2519, doi:10.3762/bjoc.17.168

• anhydrous ethanol and the formed imine was then reduced in situ with sodium borohydride to give the product 3a with 98% yield. The synthesis of further N-benzylated aminoacetaldehyde acetals 3b–e was performed in these reaction conditions in EtOH or MeOH to provide the desired products with high overall

Exfoliated black phosphorous-mediated CuAAC chemistry for organic and macromolecular synthesis under white LED and near-IR irradiation

• Azra Kocaarslan,
• Zafer Eroglu,
• Önder Metin and
• Yusuf Yagci

Beilstein J. Org. Chem. 2021, 17, 2477–2487, doi:10.3762/bjoc.17.164

• cooled to 393 K in 5 h, and it was left for natural cooling afterwards. After the heating process, the ampoule was cracked in dry toluene and the crystalline BP was separated. In order to remove surface impurities, the BP crystals were transferred into absolute ethanol and sonicated for 30 minutes. The

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

• stereoselective reduction (Scheme 8). Among a selection of reagents, Mohapatra found that lithium tri-tert-butoxyaluminum hydride in ethanol at low temperature furnished 71 as a single diastereoisomer in 94% yield. The allylic alcohol moiety was protected as TBDPS ether 73 (92%) and oxidatively cleaved following

A visible-light-induced, metal-free bis-arylation of 2,5-dichlorobenzoquinone

• Pieterjan Winant and
• Wim Dehaen

Beilstein J. Org. Chem. 2021, 17, 2315–2320, doi:10.3762/bjoc.17.149

• controlled generation of radicals resulting in a slightly higher yield compared to blue LEDs. Aside from methanol, the reaction product also precipitates from both ethanol and isopropanol, however, no increase in yield was observed (Table 1, entries 8 and 9). A control experiment was carried out omitting the

Facile and innovative catalytic protocol for intramolecular Friedel–Crafts cyclization of Morita–Baylis–Hillman adducts: Synergistic combination of chiral (salen)chromium(III)/BF₃·OEt₂ catalysis

• Karthikeyan Soundararajan,
• Helen Ratna Monica Jeyarajan,
• Raju Subimol Kamarajapurathu and
• Karthik Krishna Kumar Ayyanoth

Beilstein J. Org. Chem. 2021, 17, 2186–2193, doi:10.3762/bjoc.17.140

• ; found, 174.0706 Synthesis of 1-benzylidene-3-oxopyrazolidin-1-ium-2-ide (7a) A methyl acrylate (0.0225 mol) solution was added drop-wise to the solution of hydrazine monohydrate (0.0205 mol) in 20 mL of ethanol. This solution was stirred at 78 °C for 4 hours; the solvent was evaporated and the residue

Catalyzed and uncatalyzed procedures for the syntheses of isomeric covalent multi-indolyl hetero non-metallides: an account

• Ranadeep Talukdar

Beilstein J. Org. Chem. 2021, 17, 2102–2122, doi:10.3762/bjoc.17.137

• (Scheme 13) to afford the products 95 or 96, respectively [76]. Manishankar and co-workers dealt with a facile Fischer indole process to convert thiodiketones 97 to bis(indol-3-yl)sulfides 98 by refluxing them with phenylhydrazine hydrochloride salt in ethanol [81]. Interestingly, changing the solvent to

• THF switched the product to thioketone 99 (Scheme 14). Refluxing the thioketones 99 again with phenylhydrazine hydrochloride in ethanol resulted in the desired bis(indol-3-yl)sulfides 98. On the other hand, the treatment of thioketones 99 with phenylhydrazine afforded the corresponding hydrazones 100

• the desired product 137a. In a parallel pathway the product decomposes to selenone 144, 3-(phenylthio)indole (139) and regenerates Se. In a recent effort by Talukdar, the cheap and non-anhydrous solvent ethanol was used to prepare the desired bis(indol-3-yl)selanes 136 in moderate yields [98

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

• work on this question is needed [63][75]. The volatiles found to be emitted from black poplar endophytic fungi in this study could have important biological activities. For instance, ethanol (17) and 2-phenylethanol (3) are known to have antifungal and phytotoxic activity and so could help the

• . The samples were centrifuged for 10 min (15,000 rpm), and the upper, aqueous phase was then transferred to a new tube and DNA was precipitated in 395 µL of 100% isopropanol (−20 °C). After centrifugation (4 °C, 20 min, 15,000 rpm) the pellet was washed with 750 µL 70% ethanol, centrifuged at 15,000

Methodologies for the synthesis of quaternary carbon centers via hydroalkylation of unactivated olefins: twenty years of advances

• Thiago S. Silva and
• Fernando Coelho

Beilstein J. Org. Chem. 2021, 17, 1565–1590, doi:10.3762/bjoc.17.112

• substituted hydrazones obviated their generation in situ, and as ethanol was identified as a better solvent in the initial coupling step, no solvent exchange was necessary in the fragmentation step of the hydrazide intermediate. The addition of triethylamine and heating the reaction to 80 °C for 1 hour were

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

• intermediate 4. Reaction conditions: a) i) TFAA, collidine, 0 °C, 30 min; ii) K2CO3, rt, 30 min, 99%; b) benzylamine, DCE, THF, sodium triacetoxyborohydride, N2, rt, 24 h, 60%; c) ethanol, 10% Pd/C, H2, rt, 24 h, 84%; d) Boc anhydride, DMAP, THF, rt, overnight, 100%; e) Na, NH3, THF, -60 °C, 1 h, 81

• %. Synthesis of ent-pavettamine as the TFA salt 28. Reaction conditions: a) IBX, DMSO, rt, overnight, quantitative yield; b) TsCl, DMAP, DCM, rt, 24 h, 83%; c) NaN3, DMF, 80 °C, 3 h, 75% yield; d) 10% Pd/C, H2, ethanol, rt, 12 h, quantitative yield; e) sodium triacetoxyborohydride, 1,2-DCE, THF, rt, 24 h, 95

Double-headed nucleosides: Synthesis and applications

• Vineet Verma,
• Jyotirmoy Maity,
• Vipin K. Maikhuri,
• Ritika Sharma,
• Himal K. Ganguly and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2021, 17, 1392–1439, doi:10.3762/bjoc.17.98

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

• industrialized total synthesis of a nontrivial natural product. The original experimental protocol was recently improved by replacing the inorganic base (KOH, NaOH) with the amidine base diazobicycloundecane (DBU) as well as ethanol with n-propanol [49]. The type-III Guareschi reaction is a three-component

• of the imide slowly forms. After stirring for 24–36 h, the precipitate is filtered, and the filtrate, after washing with ethanol or diethyl ether, is acidified to precipitate the imide. In the course of the work-up, Guareschi noticed the formation of copious gas, bubbling from the solution of the

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Synthesis of functionalized imidazo[4,5-e]thiazolo[3,2-b]triazines by condensation of imidazo[4,5-e]triazinethiones with DMAD or DEAD and rearrangement to imidazo[4,5-e]thiazolo[2,3-c]triazines

• Alexei N. Izmest’ev,
• Dmitry B. Vinogradov,
• Natalya G. Kolotyrkina,
• Angelina N. Kravchenko and
• Galina A. Gazieva

Beilstein J. Org. Chem. 2021, 17, 1141–1148, doi:10.3762/bjoc.17.87

• also Supporting Information File 1 for details). The reaction of 5,7-dimethylimidazo[4,5-e]triazine-3-thione (3a) with DEAD proceeded in alcohols with moderate regioselectivity and isomer 5 predominated in the filtered precipitates (Table 1, entries 1–3). The use of absolute or 95% ethanol as a solvent