A new platform for the synthesis of diketopyrrolopyrrole derivatives via nucleophilic aromatic substitution reactions

• Vitor A. S. Almodovar and
• Augusto C. Tomé

Beilstein J. Org. Chem. 2024, 20, 1933–1939, doi:10.3762/bjoc.20.169

• synthesis of highly fluorescent DPP derivatives through straightforward nucleophilic aromatic substitution reactions with thiols and phenols. These nucleophilic substitutions occur at room temperature and manifest a remarkable selectivity for the 4-position of the pentafluorophenyl groups. Both symmetrical

• , 120 °C, 2 h) resulted in very low yields (6–16%) for the formation of N,N’-bis(pentafluorobenzyl)-DPP derivatives [36]. Changing the base to NaH and performing the reaction at a lower temperature, enabled to obtain DPP 2 in a reasonable yield (61%) and allowed us to use it as a starting material for

• performed in dry DMF at room temperature, in the presence of a base (K2CO3 or Cs2CO3). Room temperature was chosen due to the observed rapid degradation of the starting material at elevated temperatures. The work described herein allowed us to assess the potential of DPP 2 as a novel platform for obtaining

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

• and the temperature, all oxime derivatives underwent reduction to yield the corresponding amine. The amino esters were effectively safeguarded against degradation through the immediate formation of the HCl salt or by Boc-protection. This procedure allowed us to obtain all the protected amino acids in

• protocols [70][71]. In these experiments, compounds 6b and 6i proved to be unstable under on-DNA conditions as they failed to form esters 8b and 8i. Closely related structures, such as α-aminobenzothiazol-2-ylacetic acid is known to undergo decarboxylation at room temperature [72]. Compound 8t underwent

Solvent-dependent chemoselective synthesis of different isoquinolinones mediated by the hypervalent iodine(III) reagent PISA

• Ze-Nan Hu,
• Yan-Hui Wang,
• Jia-Bing Wu,
• Ze Chen,
• Dou Hong and
• Chi Zhang

Beilstein J. Org. Chem. 2024, 20, 1914–1921, doi:10.3762/bjoc.20.167

• using 2-alkenylbenzamide derivatives as substrates (Scheme 1). Results and Discussion We began by exploring the reaction of N-methoxy-2-(prop-1-en-2-yl)benzamide (1a) with PISA (1.5 equiv) in anhydrous acetonitrile at room temperature under argon atmosphere. 4-Methylisoquinolinone 2a was the sole

• were as follows: 1.5 equivalents of PISA and 4 Å MS in anhydrous CH3CN (0.1 M of 2a) under argon atmosphere at room temperature for 20 min. With the optimal reaction conditions in hand, we explored the scope of the method by testing various 2-alkenylbenzamide derivatives 1 (Scheme 2). When R1 was ethyl

• of 3-methylisoquinolinone as follows: reacting 1.1 equivalents of PISA in HFIP (0.1 M of 1a) containing 2.5 equivalents of H2O at room temperature for 20 minutes (Scheme 3). The general applicability of PISA in wet HFIP solvent was studied. When R1 was ethyl, isopropyl, cyclopropyl, or hydrogen

Electrochemical radical cation aza-Wacker cyclizations

• Sota Adachi and
• Yohei Okada

Beilstein J. Org. Chem. 2024, 20, 1900–1905, doi:10.3762/bjoc.20.165

• appropriate alkene (0.20 mmol), TFA (0.20 mmol), and CH3CN (0.4 mL) were added to a solution of Bu4NOTf/1,2-DCE (0.10 M, 3.6 mL) while stirring at room temperature. The resulting reaction mixture was electrolyzed at 1 mA using a CF anode (10 mm × 10 mm) and a Pt cathode (10 mm × 20 mm) in an undivided cell

Access to 2-oxoazetidine-3-carboxylic acid derivatives via thermal microwave-assisted Wolff rearrangement of 3-diazotetramic acids in the presence of nucleophiles

• Ivan Lyutin,
• Vasilisa Krivovicheva,
• Grigory Kantin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2024, 20, 1894–1899, doi:10.3762/bjoc.20.164

• high yields of the target compounds. When stored individually or in solution at room temperature, the acids 4 gradually decompose and undergo decarboxylation and other accompanying processes. The example of acid 4a demonstrates the possibility of easy amidation to form new β-lactam derivatives 3s and

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

• reactions, if we exclude a 96-member library of GBB adducts reported very recently by Dömling et al. [9]. In this case, however, Sc(OTf)3 was used as the catalyst and the choice for ethylene glycol was dictated by the need to have a polar solvent with a high boiling temperature. Shankar et al., however

• discussed in more details in chapter 2). Another recent article on the use of Brønsted acids has been reported by Vilapara et al., who employed for the first time etidronic acid (1-hydroxyethane-1,1-diphosphonic acid, HEDP) as a green catalyst. Reactions were efficient at room temperature [11]; although the

• -free conditions at room temperature for 2 h [16]. Although thiamine had already been reported to be effective in other chemical transformations and its role in carbonyl activation in vivo through its thiazole ring is well known, no mechanism of action in the GBB condensation was proposed by the authors

A facile three-component route to powerful 5-aryldeazaalloxazine photocatalysts

• Ivana Weisheitelová,
• Radek Cibulka,
• Marek Sikorski and
• Tetiana Pavlovska

Beilstein J. Org. Chem. 2024, 20, 1831–1838, doi:10.3762/bjoc.20.161

• , 1.0 mmol). As illustrated in Table 1, DMSO was preferred as the optimal solvent, and 130 °C was chosen as the most suitable reaction temperature (Table 1, entry 1). Other solvents showed low yields, or the product was not isolated at all. However, we found that the yield of 5-phenyldeazaalloxazine 2a

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

• mL urea buffer (8 M urea, 100 mM NaH2PO4, 10 mM Tris-base), pH 8.0, frozen at −80 °C, and then thawed at room temperature. The cell lysate was clarified by centrifugation and incubated with 1 mL Ni-NTA resin (Qiagen). The precursor protein was purified using the standard protocol from Qiagen for

• GraphPad (version 8.0.2). Atomic force microscopy AFM characterization was conducted using a MultiMode 8-HR (Bruker). Samples containing S. epidermis at an OD600 > 1 were incubated with the lanthipeptides at room temperature for 1 and 5 hours. Subsequently, 9 µL of the samples were combined with 1 µL of a

• 0.1% w/v poly-ʟ-lysin solution in water (Sigma-Aldrich) and immediately deposited onto freshly cleaved mica to be incubated for 10 min at room temperature to allow adsorption. The surface was then rinsed using 600 µL of ultrapure 0.2 µm filtered water and slowly dried using compressed air. Imaging was

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

• efficient separation from the excess Selectfluor and its byproduct. Reducing the amount of Selectfluor to 2.5 equivalents and the reaction time to 24 hours (Table 2, entry 2) resulted in a similar high yield of difluoroiodane 6. The reaction also proceeded well at either room temperature for 24 hours (Table

• afford iodoalcohol 14 in 93% yield. In the final step iodoalcohol 14 underwent an oxidative fluorination with Selectfluor at room temperature to deliver methyl(trifluoromethyl)fluoroiodane 15 in a good 68% yield after recrystallisation from toluene. Although bis(trifluoromethyl)fluoroiodane 19 has been

• charged to a dry Schlenk flask under a nitrogen atmosphere. The flask was sealed and heated to 40 °C for 24 hours. After cooling the reaction mixture to room temperature, the solvent was removed in vacuo to afford a crude orange solid. The orange solid was extracted with dry dichloromethane (3 × 5 mL

Ugi bisamides based on pyrrolyl-β-chlorovinylaldehyde and their unusual transformations

• Alexander V. Tsygankov,
• Vladyslav O. Vereshchak,
• Tetiana O. Savluk,
• Serhiy M. Desenko,
• Valeriia V. Ananieva,
• Oleksandr V. Buravov,
• Yana I. Sakhno,
• Svitlana V. Shishkina and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2024, 20, 1773–1784, doi:10.3762/bjoc.20.156

• possibilities for subsequent post-transformation reactions. The synthesis of the target Ugi bisamides 5–8 was carried out at room temperature in ethanol with stirring for 24–48 hours (depending on the type of starting material) with a yield of 54–93% (Table 1). It is worth noting that the Ugi-4CR reaction also

• amount of HCl or replacing it with chloroacetic acid under otherwise identical conditions had no significant effect on the yields of products 10 and 12 (Table 2, entries 28–32). At the same time, decreasing the temperature of the post-Ugi transformation of bisamide 8c in the presence of HCl to 25 °C

• corresponding amide 10. The expected fact that the amides 10 could not be formed from the ketobisamides 12 (Table 3) was also confirmed; stirring the latter in MeCN or EtOH in the presence of HCl at room temperature or under heating did not lead to formation, not even to the appearance of traces of the amide

Harnessing unprotected deactivated amines and arylglyoxals in the Ugi reaction for the synthesis of fused complex nitrogen heterocycles

• Javier Gómez-Ayuso,
• Pablo Pertejo,
• Tomás Hermosilla,
• Israel Carreira-Barral,
• Roberto Quesada and
• María García-Valverde

Beilstein J. Org. Chem. 2024, 20, 1758–1766, doi:10.3762/bjoc.20.154

• procedure. Thus, initially the amine 3 (1 equiv) was added to a solution of the arylglyoxal 1 (1 equiv) in methanol and the mixture was stirred for 15 min. Then, the acid 2 (1 equiv) and the isocyanide 4 (1 equiv) were added and the reaction was stirred at room temperature for 24 h. Fortunately, after the

Synthesis of polycyclic aromatic quinones by continuous flow electrochemical oxidation: anodic methoxylation of polycyclic aromatic phenols (PAPs)

• Hiwot M. Tiruye,
• Solon Economopoulos and
• Kåre B. Jørgensen

Beilstein J. Org. Chem. 2024, 20, 1746–1757, doi:10.3762/bjoc.20.153

• . HCl and 3–4 drops of water. The mixture was stirred at room temperature for 0.5 h and poured into ice water (5 mL). The precipitated quinone was filtered off, thoroughly washed with water, and dried under vacuum to yield the pure product. General procedure C: combined electrochemical oxidation and

• hexafluorophosphate ([NBu4] [PF6]) solution in acetonitrile. The solvent was dried and degassed using N2 prior to each experiment. All experiments were conducted at room temperature. All redox potentials were calibrated against ferrocene/ferrocenium (Fc/Fc+) redox couple. Cyclic voltammograms of PAPs first scan at

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

• ether 39, a ring-closing enyne metathesis (RCEYM) was initiated using the Grubbs second-generation catalyst (G-II) and high temperature to obtain the spiro 2,5-dihydrofuran derivative 40 in 76% yield. Additionally, when a dienophile such as N-phenylmaleimide was directly added to the same pot and

• tolylhydrazonoyl chloride derivative 54 [35]. The reaction conducted in the presence of silver acetate at room temperature, achieved yields of 78–81% of the 16-spiropyrazolines 55a,b (Scheme 17). 6-Spiroimidazoline steroids In 2015, Dar’s group reported a small library of spiroimidazo[1,2-a]pyridines obtained

A fiber-optic spectroscopic setup for isomerization quantum yield determination

• Anouk Volker,
• Jorn D. Steen and
• Stefano Crespi

Beilstein J. Org. Chem. 2024, 20, 1684–1692, doi:10.3762/bjoc.20.150

• setup assembled in-house, see Figure 2 and Supporting Information File 1. A Quantum Northwest Luma 40 Peltier-based temperature-controlled cuvette holder with an insulator jacket with four optical windows was used to allow irradiation perpendicular to the spectrometer light path. The light source is an

• measurement altering the kinetics of isomerization, a known problem for similar setups [24]. The power readings from the thermal power sensor were recorded by using Thorlabs’ Optical Power Monitor (OPM) software. The resulting data showed some fluctuations depending on environment temperature and air movement

• . The inclusion of a temperature-controlled cuvette holder and the possibility for simultaneous UV–vis absorption spectroscopy makes this setup ideally suitable for a wide range of photoswitches, including those with fast thermal back isomerization. Our setup was tested by determining the quantum yields

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

• tetrazine salt 1c. Based on these results, the reaction conditions were further optimized using NHI 1a with the benzyl alcohols 3a (electron-rich) and 3b (electron-poor) as the model substrates. First, the reaction temperature was increased, finding 60 °C to be the optimal value in EtOAc (Table 1, entry 1

• ). At this temperature, the reaction time was significantly reduced to 2.5 h. A variety of other additives were tested next, revealing TsOH or NaOTs inhibiting the reaction (Table 1, entries 2 and 3). The addition of tetrabutylammonium halides showed the chloride salt being superior, giving comparable

Ring opening of photogenerated azetidinols as a strategy for the synthesis of aminodioxolanes

• Henning Maag,
• Daniel J. Lemcke and
• Johannes M. Wahl

Beilstein J. Org. Chem. 2024, 20, 1671–1676, doi:10.3762/bjoc.20.148

•  1), we successfully conducted the desired sequence by raising the temperature to 100 °C to initiate ring opening, and employing a mild transesterification method for diol release [43][44][45]. Thus, we were able to isolate 3-amino-1,2-diol 21 in 49% yield. Conclusion Within this work, we

Polymer degrading marine Microbulbifer bacteria: an un(der)utilized source of chemical and biocatalytic novelty

• Weimao Zhong and
• Vinayak Agarwal

Beilstein J. Org. Chem. 2024, 20, 1635–1651, doi:10.3762/bjoc.20.146

• enzyme RagaA7 was produced in a Bacillus subtilis host and characterized to be a neoagarotetraose-producing GH-16 family endo-type β-agarase with a pH and temperature optima being 7.0 and 50 °C, respectively. Another thermostable neoagarotetraose-producing GH-16 endo-type β-agarase rAgaA was identified

• and cloned from deep-sea-derived Microbulbifer sp. JAMB-A94 with pH and temperature optima being 7.0 and 55 °C, respectively [26]. The recombinant enzyme was likewise produced using a B. subtilis host. The crystal structure of the catalytic domain was determined to show a β-jelly roll fold with

• bridges, relatively short length of the surface loops, and the increased number of Pro and Arg residues [29]. A truncated β-agarase gene without the carbohydrate-binding modules (Aga16A-ΔCBM) from the marine Microbulbifer sp. BH-1 was cloned and expressed in Escherichia coli with pH and temperature being

New triazinephosphonate dopants for Nafion proton exchange membranes (PEM)

• Fátima C. Teixeira,
• António P. S. Teixeira and
• C. M. Rangel

Beilstein J. Org. Chem. 2024, 20, 1623–1634, doi:10.3762/bjoc.20.145

• structural properties of the membranes restrain their stability and durability, their humidity and temperature application conditions, and their efficiency and consequently, the performance of fuel cells or eletrolysers [18][19]. Many organic polymers with acidic functional groups have been developed as

• acid groups [22]. These membranes have an excellent chemical stability, but their high proton conduction is dependent of the water content of the membranes which limits their operating temperature range to 80 °C [23]. The importance of the membranes for the new sustainable energy sources fostered the

• 10 mV, over a frequency range of 65 kHz to 5 Hz. The bulk resistance (Rb) of the membranes were calculated using the ZView software (Version 2.6b, Scribner Associates). A Binder KBF 115 climatic chamber was used to perform the measurements at a temperature of 60 °C and different relative humidity (RH

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

• ; visible light; Introduction Solar energy is of paramount importance to life on the earth for various reasons, such as maintenance of a stable temperature and enabling photosynthesis as the basis of the food chain. Inspired by the natural photosynthetic processes, synthetic molecules were designed and

• path length. A Luma 40/Cary 60 temperature-controlled cuvette holder with four optical ports was mounted in the sample compartment. UV–vis irradiation was carried out at 20 °C using a Thorlabs model M625F2 high-power LED (625 nm, 1.0 A) (625 nm, 1.0 A) and a light-guide-equipped BBZM-I xenon light

• sonicated for 10 min at room temperature to afford a deep-purple solution. The obtained solution was directly used or diluted for microscopic and spectroscopic measurements. TEM TEM was performed on a JEOL model JEM-2010 transmission electron microscope with tungsten hair pin type filament operating at 120

Electrocatalytic hydrogenation of cyanoarenes, nitroarenes, quinolines, and pyridines under mild conditions with a proton-exchange membrane reactor

• Koichi Mitsudo,
• Atsushi Osaki,
• Haruka Inoue,
• Eisuke Sato,
• Naoki Shida,
• Mahito Atobe and
• Seiji Suga

Beilstein J. Org. Chem. 2024, 20, 1560–1571, doi:10.3762/bjoc.20.139

• cyanoarenes, nitroarenes, quinolines, and pyridines using a proton-exchange membrane (PEM) reactor was developed. Cyanoarenes were then reduced to the corresponding benzylamines at room temperature in the presence of ethyl phosphate. The reduction of nitroarenes proceeded at room temperature, and a variety of

• mmol; solvent, CH2Cl2 (0.5 M); flow rate of the solution of 6a, 0.75 mL min−1; flow rate of H2 gas, 100 mL min−1; reaction temperature, room temperature; current density, 50 mA cm−2. The solution was circulated until the passage of 50 F mol−1 (10 h). The yields were determined by 1H NMR analysis using

• H2 gas, 100 mL min−1; reaction temperature, room temperature; current density, 50 mA cm−2 (10 h). The solution was circulated until the passage of 50 F mol−1. The yields were determined by 1H NMR analysis using 1,1,2,2-tetrachloroethane as an internal standard. Plausible mechanism for the reduction

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

• attributed this to the increased solubility and concentration of NFSI in the AIBN conditions, which were performed at elevated temperatures, promoting facile trapping of a primary radical. In contrast, the decatungstate conditions, which operated at room temperature where NFSI is not completely dissolved and

• authors noted a sensitivity to the fluoride source, with Et3N·5HF determined to be superior, and reaction temperature, as demonstrated by fluctuations in the yield of product 17 depending on the reaction temperature. In 2003, Fuchigami and co-workers also reported the use of Et3N·5HF in combination with

Primary amine-catalyzed enantioselective 1,4-Michael addition reaction of pyrazolin-5-ones to α,β-unsaturated ketones

• Pooja Goyal,
• Akhil K. Dubey,
• Raghunath Chowdhury and
• Amey Wadawale

Beilstein J. Org. Chem. 2024, 20, 1518–1526, doi:10.3762/bjoc.20.136

• primary amine catalysts (see Table S1 in Supporting Information File 1) in toluene at room temperature (30–32 °C). When the test reaction was conducted in the presence of 15 mol % of 9-amino-9-deoxy-epicinchonidine (I) as catalyst [30] for 12 h and treated with Ac2O followed by DABCO, the reaction gave

• (Table 1, entry 8). When the catalyst loading was lowered (10 mol % of I/20 mol % of A5), the desired product 3aa was obtained in 71% yield and 91% ee (Table 1, entry 10). Lowering the temperature (−20 °C) of the reaction improved the enantioselectivity of the product 3aa slightly but decreased its yield

• (Table 1, entry 11). Subsequently, the effect of concentration on the reaction outcome was also studied. In dilute conditions, both the yield and enantioselectivity of the product 3aa were improved to 80% and 94%, respectively, at room temperature (Table 1, entry 12). Taking into account the results of

Towards an asymmetric β-selective addition of azlactones to allenoates

• Behzad Nasiri,
• Ghaffar Pasdar,
• Paul Zebrowski,
• Katharina Röser,
• David Naderer and
• Mario Waser

Beilstein J. Org. Chem. 2024, 20, 1504–1509, doi:10.3762/bjoc.20.134

• the use of 3 equiv Cs2CO3 in toluene (0.05 M) at room temperature as the best-suited conditions (Table 1, entry 13), allowing for the synthesis of 5a in moderate yield (61%) and enantioselectivity (81:19 er). With optimized conditions for the synthesis of enantioenriched (−)-5a at hand, we next

• ), catalyst B2 (10 mol % related to 1), and Cs2CO3 (3 equiv). Then the respective allenoate 3 (2 equiv) and toluene (0.05 M with respect to 1) were added and the mixture was stirred at room temperature for 24 h (Ar atmosphere). The crude product was passed through a short column of silicagel (rinsed with DCM

Electrophotochemical metal-catalyzed synthesis of alkylnitriles from simple aliphatic carboxylic acids

• Yukang Wang,
• Yan Yao and
• Niankai Fu

Beilstein J. Org. Chem. 2024, 20, 1497–1503, doi:10.3762/bjoc.20.133

• esters, the so called "Barton esters", for decarboxylative cyanation of aliphatic acids with tosyl cyanide as the nitrile source under visible light irradiation at room temperature [21][22]. Although two synthetic steps are required, this is the first practical decarboxylative cyanation protocol because

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

• Z/E ratios during irradiation, showing an excellent photoconversion yield of Z/E = 99:1 at PSS370, and E/Z = 87:13 at PSS485 in D2O/5% DMSO (Figure 3). As the Z-isomer is metastable, its half-life has been determined to be 44.4 h in water at room temperature (Figure S9 in Supporting Information File

• the half-live varied from 26 h to 29 days at room temperature depending on the type of glycosidic linkage and the substitution pattern on the azobenzene moiety. The bistability of the azobenzene derivatives is suitable for the investigation of azobenzene isomers on the binding affinity with LecA. All

• was stirred at room temperature until total deprotection. The solution was neutralized using Amberlite IR-120 (H), filtered, concentrated and the crude material used without further purification to give the desired product in quantitative yield. (A) Selected monovalent inhibitors for PA LecA and (B