Recent advances in synthetic approaches for bioactive cinnamic acid derivatives

• Betty A. Kustiana,
• Galuh Widiyarti and
• Teni Ernawati

Beilstein J. Org. Chem. 2025, 21, 1031–1086, doi:10.3762/bjoc.21.85

Synthesis, characterization, antimicrobial, cytotoxic and carbonic anhydrase inhibition activities of multifunctional pyrazolo-1,2-benzothiazine acetamides

• Ayesha Saeed,
• Shahana Ehsan,
• Muhammad Zia-ur-Rehman,
• Erin M. Marshall,
• Sandra Loesgen,
• Abdus Saleem,
• Simone Giovannuzzi and
• Claudiu T. Supuran

Beilstein J. Org. Chem. 2025, 21, 348–357, doi:10.3762/bjoc.21.25

• ) products and with alkylating agents 6i–n to give the N- and O-alkylated (dialkylated) products. The alkylation of compound 5 was controlled by the molar quantities of alkylating agents and base present. Thus, compound 5 was N-alkylated using equimolar quantities of the alkylating agents 6a–h to give the

• respective derivatives 7a–h. On the other hand, compound 5 was N-alkylated as well as O-alkylated using 2.0 equivalents of alkylating agents 6i–n to yield the respective derivatives 7i–n. The formation of monoalkylated derivatives is based on the fact that the NH group of the pyrazole ring in 5 is more

• 5.30 ppm for the two protons of each methylene group (Figure 2b). These compounds showed two individual singlets each for one NH proton in the range of 9.54–11.06 ppm (Figure 2a). The absence of signals near 13 ppm for OH protons confirms the formation of N- and O-alkylated compounds 7i–n. Both sets of

Skeletal rearrangement of 6,8-dioxabicyclo[3.2.1]octan-4-ols promoted by thionyl chloride or Appel conditions

• Martyn Jevric,
• Julian Klepp,
• Johannes Puschnig,
• Oscar Lamb,
• Christopher J. Sumby and
• Ben W. Greatrex

Beilstein J. Org. Chem. 2024, 20, 823–829, doi:10.3762/bjoc.20.74

• mixture of ketone 9e and the O-alkylated enol ether by-product, which was then reduced using NaBH4 to give alcohol 10e with 98:2 selectivity. Similarly, the reaction of 4-methoxybenzyl bromide and 2 gave ketone 9f in 35% yield without chromatography, and when reduced resulted in only a single alcohol

A novel recyclable organocatalyst for the gram-scale enantioselective synthesis of (S)-baclofen

• Gyula Dargó,
• Dóra Erdélyi,
• Balázs Molnár,
• Péter Kisszékelyi,
• Zsófia Garádi and
• József Kupai

Beilstein J. Org. Chem. 2023, 19, 1811–1824, doi:10.3762/bjoc.19.133

• the other components of the reaction mixture. The lipophilic O-alkylated gallic acid unit increases the solubility of the organocatalyst in less polar solvents, such as DCM or toluene but leads to the precipitation of the organocatalyst in polar solvents, including MeOH or MeCN. As a result, the

Synthesis and biological evaluation of Argemone mexicana-inspired antimicrobials

• Jessica Villegas,
• Bryce C. Ball,
• Katelyn M. Shouse,
• Caleb W. VanArragon,
• Ashley N. Wasserman,
• Hannah E. Bhakta,
• Allen G. Oliver,
• Danielle A. Orozco-Nunnelly and
• Jeffrey M. Pruet

Beilstein J. Org. Chem. 2023, 19, 1511–1524, doi:10.3762/bjoc.19.108

• . Conversion of naphthols to naphthylamines is typically achieved through a three-step sequence whereby the naphthol is first O-alkylated with 2-bromo-2-methylpropionamide and this ether undergoes a Smiles rearrangement to the hydroxyamide, which is hydrolyzed to the free naphthylamine [44][45]. It has

Cationic oligonucleotide derivatives and conjugates: A favorable approach for enhanced DNA and RNA targeting oligonucleotides

• Mathias B. Danielsen and
• Jesper Wengel

Beilstein J. Org. Chem. 2021, 17, 1828–1848, doi:10.3762/bjoc.17.125

• effects of different amine-functionalized groups. Beginning with the 2’-O-alkylated RNA nucleotides (Table 4) it has been shown that the introduction of an aminopropyl group via 2’-O-alkylation (modification 34) leads to moderately improved hybridization properties for the modified ON against its RNA

Synthesis of 9-O-arylated berberines via copper-catalyzed C_Ar–O coupling reactions

• Qiaoqiao Teng,
• Xinhui Zhu,
• Qianqian Guo,
• Weihua Jiang,
• Jiang Liu and
• Qi Meng

Beilstein J. Org. Chem. 2019, 15, 1575–1580, doi:10.3762/bjoc.15.161

• the fact that 9-O-functionalization is well-established. Therefore, to further diversify the BBR structure and to provide more potent drug candidates in the future, we herein report the first synthetic study on 9-O-arylated berberine. Results and Discussion In an analogous manner as described for 9-O

• -alkylated BBR, the synthesis of 9-O-phenyl BBR 3a was initially attempted by direct cross-coupling of berberrubine (BBRB) with phenyl iodide, using CuI and 1,10-phenanthroline as the pre-catalyst and K2CO3 as the base [18][19]. However, under these reaction conditions not any desired product was formed, and

Mechanochemical N-alkylation of imides

• Anamarija Briš,
• Mateja Đud and
• Davor Margetić

Beilstein J. Org. Chem. 2017, 13, 1745–1752, doi:10.3762/bjoc.13.169

• considered for LAG in mechanosynthesis. A comparison of results with literature values demonstrates the benefits of mechanosynthesis. For instance, alkylation of theobromine (14) [34] in a microwave reactor in solution gives two side-products, an O-alkylated and a uracil ring-opened product (induced by base

O-Alkylated heavy atom carbohydrate probes for protein X-ray crystallography: Studies towards the synthesis of methyl 2-O-methyl-L-selenofucopyranoside

• Roman Sommer,
• Dirk Hauck,
• Annabelle Varrot,
• Anne Imberty,
• Markus Künzler and
• Alexander Titz

Beilstein J. Org. Chem. 2016, 12, 2828–2833, doi:10.3762/bjoc.12.282

• carbohydrate epitopes with O-alkylated ring hydroxy groups. In this context, we report the first synthesis of an O-methylated selenoglycoside, specifically methyl 2-O-methyl-L-selenofucopyranoside, a ligand of the lectin tectonin-2 from the mushroom Laccaria bicolor. The synthetic route required a strategic

• glycans in pathogens or parasites, numerous other lectins recognize such O-alkylated ligands, e.g., the pilus adhesin from Pseudomonas aeruginosa PAK [31] or PapG from Escherichia coli [32]. In contrast, methylation of lectin ligands can also prevent binding, as observed with O-methylated fucose and

• mannose for P. aeruginosa LecB or B. cenocepacia BC2L-A [33]. Thus, O-methylation of glycans can tune biological recognition events. In contrast to the literature reports on the synthesis of unmodified seleno glycosides, the synthesis of selectively O-alkylated derivatives to study their interactions with

Organofluorine chemistry: Difluoromethylene motifs spaced 1,3 to each other imparts facial polarity to a cyclohexane ring

• Mathew J. Jones,
• Ricardo Callejo,
• Alexandra M. Z. Slawin,
• Michael Bühl and
• David O'Hagan

Beilstein J. Org. Chem. 2016, 12, 2823–2827, doi:10.3762/bjoc.12.281

• relationship. Results and Discussion The preparation of diketones 5a–c and bis-dithianes 6a–c was carried out by previously described methods. The dimethyl-diketone 5c was prepared by double methylation of 5b [25] (Scheme 2). Two different O-alkylated products 7 and 8 were also obtained as significant

Diastereoselective synthesis of new O-alkylated and C-branched inositols and their corresponding fluoro analogues

• Charlotte Collet,
• Françoise Chrétien,
• Yves Chapleur and
• Sandrine Lamandé-Langle

Beilstein J. Org. Chem. 2016, 12, 353–361, doi:10.3762/bjoc.12.39

• derivatives, bearing an arm terminated either with a hydroxy group or a fluorine atom, could be interesting candidates for diastereoisomeric intermediates and biological evaluations, especially for PET imaging experiments. Keywords: C-branched; diastereoselective; fluoroinositols; inositols; O-alkylated

• instance through radiolabeled compounds, seems judicious. Thus we planned to study new synthetic inositols of myo- and scyllo-configuration equipped with different carbon chains linked either on one hydroxy group, i.e., O-alkylated, or C-branched derivatives retaining the six hydroxy groups of the inositol

• -inosose 7 [41] that can be easily obtained at large scale from commercially available myo-inositol. The introduction of the arm into the inositol backbone through an O–C linker (O-alkylated) or a C–C linker (C-branched) to afford diastereoselectively myo- and scyllo-derivatives was the key step. In the

Recent developments in copper-catalyzed radical alkylations of electron-rich π-systems

• Kirk W. Shimkin and
• Donald A. Watson

Beilstein J. Org. Chem. 2015, 11, 2278–2288, doi:10.3762/bjoc.11.248

• significant amounts of products resulting from O-alkylation (Scheme 2). β-Diketimine (nacnac) ligands were determined to be highly effective for the reaction, providing high yields of C-alkylated products and only trace amounts of O-alkylated products. These types of ligands have recently found use in copper

Synthesis and chemosensing properties of cinnoline-containing poly(arylene ethynylene)s

• Natalia A. Danilkina,
• Petr S. Vlasov,
• Semen M. Vodianik,
• Andrey A. Kruchinin,
• Yuri G. Vlasov and
• Irina A. Balova

Beilstein J. Org. Chem. 2015, 11, 373–384, doi:10.3762/bjoc.11.43

• examples of dimers and trimers were studied to date [36]. The O-alkylated hydroquinone scaffold was chosen as a commonly used spacer between the diethynylcinnoline units [2][3][4] that prevents the aggregation of polymer chains. An efficient modification of the Richter type cyclization [37][38] based on

Selective methylation of kaempferol via benzylation and deacetylation of kaempferol acetates

• Qinggang Mei,
• Chun Wang,
• Weicheng Yuan and
• Guolin Zhang

Beilstein J. Org. Chem. 2015, 11, 288–293, doi:10.3762/bjoc.11.33

• . On the other hand, O-methylation is an effective approach to protect the reactive hydroxy groups of flavonoids and a strategy to improve the physicochemical properties such as solubility and intracellular compartmentation [18]. Some of the O-alkylated flavonoids possess biological activities, and

Investigations of thiol-modified phenol derivatives for the use in thiol–ene photopolymerizations

• Sebastian Reinelt,
• Monir Tabatabai,
• Urs Karl Fischer,
• Norbert Moszner,
• Andreas Utterodt and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 1733–1740, doi:10.3762/bjoc.10.180

• the reaction sequence and yielded compound 3. The quantitative etherification of the phenolic hydroxy groups with potassium carbonate and ethyl iodide yielded the corresponding ether derivative 5. Subsequently the remaining hydroxy groups of 3 and 5 were o-alkylated in the presence of a strong base

Synthesis and solvodynamic diameter measurements of closely related mannodendrimers for the study of multivalent carbohydrate–protein interactions

• Yoann M. Chabre,
• Alex Papadopoulos,
• Alexandre A. Arnold and
• René Roy

Beilstein J. Org. Chem. 2014, 10, 1524–1535, doi:10.3762/bjoc.10.157

• carbon and the benzene carbon, was prepared according to Scheme 3. Thus, phloroglucinol (13) was carefully O-alkylated with the previously synthesized bromoacetylated TRIS derivative 14 [36] using K2CO3 in DMF to provide 15 in 43% yield. Again, the structural integrity of 15 was fully assessed by the

Novel supramolecular affinity materials based on (−)-isosteviol as molecular templates

• Christina Lohoelter,
• Malte Brutschy,
• Daniel Lubczyk and
• Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2013, 9, 2821–2833, doi:10.3762/bjoc.9.317

• precursor all-syn-16 in hands and the need for organic materials with pronounced cavities as potent affinity materials we envisioned the synthesis of a capsule-type architecture. Therefore, all-syn-16 was O-alkylated by treatment with 5-bromo-1-pentene using standard conditions [70] to yield the

Fifty years of oxacalix[3]arenes: A review

• Kevin Cottet,
• Paula M. Marcos and
• Peter J. Cragg

Beilstein J. Org. Chem. 2012, 8, 201–226, doi:10.3762/bjoc.8.22

The preparation of 3-substituted-1,5-dibromopentanes as precursors to heteracyclohexanes

• Bryan Ringstrand,
• Martin Oltmanns,
• Jeffrey A. Batt,
• Aleksandra Jankowiak,
• Richard P. Denicola and
• Piotr Kaszynski

Beilstein J. Org. Chem. 2011, 7, 386–393, doi:10.3762/bjoc.7.49

• potentially general intermediate is 4-(4-hydroxyphenyl)tetrahydro-4H-pyran [31], which can be O-alkylated to provide 4-alkoxyphenyl derivatives [2]. Overall, we have demonstrated that dibromides I containing simple groups, such as propyl or pentyl, can be prepared in yields of about 70% starting from

Novel tetracyclic structures from the synthesis of thiolactone-isatin hybrids

• Renate Hazel Hans,
• Hong Su and
• Kelly Chibale

Beilstein J. Org. Chem. 2010, 6, No. 78, doi:10.3762/bjoc.6.78

• regioselectively, only 9% of the desired C-4 O-alkylated product was obtained after a reaction time of 144 h. We herein report the synthesis of a novel series of thiolactone-isatin hybrids. The envisaged target compounds 3, as shown in Figure 2, are modeled on 1 but devoid of the hydrophobic side chain represented

• initially suspected it to be a regioisomer of 3, that is, the C-3-alkylated or C-2 O-alkylated product consistent with the resonance contributors of the anion of 5. Lack of regioselectivity in the alkylation reactions of thiolactomycin and its analogues is a common synthetic problem [22][23][24]. Interest

Molecular recognition of organic ammonium ions in solution using synthetic receptors

• Andreas Späth and
• Burkhard König

Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32

Comparison of zwitterionic N-alkylaminomethanesulfonic acids to related compounds in the Good buffer series

• Robert D. Long,
• Newton P. Hilliard Jr,
• Suneel A. Chhatre,
• Tatiana V. Timofeeva,
• Andrey A. Yakovenko,
• Daniel K. Dei and
• Enoch A. Mensah

Beilstein J. Org. Chem. 2010, 6, No. 31, doi:10.3762/bjoc.6.31

• attempts to synthesize N-[tris(hydroxymethyl)methyl]-aminomethanesulfonic acid [TAMS] (5) have resulted in a product that is a mixture of the desired compound with what appears to be the O-alkylated derivative. We have also attempted to synthesize N,N-bis(2-hydroxyethyl)aminomethanesulfonic acid [BAMS] (6