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

• acid (7) by using trichloroisocyanuric acid/triphenylphosphine (TCCA/PPh3) assisted by ultrasound to give the corresponding amide 34 in good yield (Scheme 12) [44]. Herein, PPh3 attacks chloride atoms in TCCA to subsequently generate phosphonium intermediate 35, followed by the formation of reactive

Photomechanochemistry: harnessing mechanical forces to enhance photochemical reactions

• Francesco Mele,
• Ana M. Constantin,
• Andrea Porcheddu,
• Raimondo Maggi,
• Giovanni Maestri,
• Nicola Della Ca’ and
• Luca Capaldo

Beilstein J. Org. Chem. 2025, 21, 458–472, doi:10.3762/bjoc.21.33

• developed, where additional energy is applied to increase mixing such as pulsation [26][27][28], ultrasound energy [29], segmented flow [30], or mechanical stirring [31]. In line with the recent emphasis on Green Chemistry principles [32][33], alternatives have been developed in order to reduce the amount

Cu(OTf)₂-catalyzed multicomponent reactions

• Sara Colombo,
• Camilla Loro,
• Egle M. Beccalli,
• Gianluigi Broggini and
• Marta Papis

Beilstein J. Org. Chem. 2025, 21, 122–145, doi:10.3762/bjoc.21.7

• compounds catalyzed by copper triflate under ultrasound irradiation allowed the one-pot formation of 1H-benzo[f]chromen-2-yl(phenyl)methanones (naphthopyranes) 37. The comparison with conventional method showed better yields and shorter reaction times. The suggested reaction mechanism showed the formation

Multicomponent reactions driving the discovery and optimization of agents targeting central nervous system pathologies

• Lucía Campos-Prieto,
• Aitor García-Rey,
• Eddy Sotelo and
• Ana Mallo-Abreu

Beilstein J. Org. Chem. 2024, 20, 3151–3173, doi:10.3762/bjoc.20.261

• other approaches such as visible light, microwaves, heterogeneous catalysis, and ultrasound [12][13][14][15]. Due to its versatility, one of the most prevalent of these MCRs is the Ugi reaction [16]. This reaction generally combines an isocyanide with an acid, an amine, and an aldehyde or ketone to

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

• addition to form the corresponding trispyrazole 35 (Scheme 10) [61]. Similarly, aromatic aldehydes furnish the corresponding bispyrazolylmethanes either under ultrasound irradiation in low-boiling solvents [62] or under Ag/TiO2 catalysis [63]. In addition to 1,3-dicarbonyl compounds, 1,3,5-tricarbonyl

Synthetic applications of the Cannizzaro reaction

• Bhaskar Chatterjee,
• Dhananjoy Mondal and
• Smritilekha Bera

Beilstein J. Org. Chem. 2024, 20, 1376–1395, doi:10.3762/bjoc.20.120

• of α-hydroxycarboxylic acids [47]. They are also used in the development of different nanoparticle preparations and other reactions for synthesis of bioactive compounds [48][49][50]. Green synthesis methodologies, such as microwave-assisted [51][52][53] and ultrasound-assisted reactions [54] are

Research progress on the pharmacological activity, biosynthetic pathways, and biosynthesis of crocins

• Zhongwei Hua,
• Nan Liu and
• Xiaohui Yan

Beilstein J. Org. Chem. 2024, 20, 741–752, doi:10.3762/bjoc.20.68

• extracting crocins include ultrasound-assisted extraction (UAE), supercritical fluid extraction, enzyme-linked extraction, and microwave-assisted extraction. Among these methods, the UAE exhibits a higher extraction yield [23][24]. Recently, Fiorito et al. developed a technique that utilizes cost-effective

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

• hydroxamic acid 6 µM; sodium butyrate 6 µM). Extraction The mycelium was separated from the fermentation broth using a centrifuge and subsequently extracted with ethanol in a 1:1 ratio using ultrasound, three times for 20 minutes each. The combined organic solvents were dried with a rotary evaporator to

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

• bonding with polar species [114]. The nanoparticle of choice was CuO, which had already displayed several varied catalytic applications, so the P4VPy–CuO nanoparticles were synthesized through an ultrasound irradiation protocol and tested in the reaction between p-chlorobenzaldehyde and indole. An amount

Synthesis of 7-azabicyclo[4.3.1]decane ring systems from tricarbonyl(tropone)iron via intramolecular Heck reactions

• Aaron H. Shoemaker,
• Elizabeth A. Foker,
• Elena P. Uttaro,
• Sarah K. Beitel and
• Daniel R. Griffith

Beilstein J. Org. Chem. 2023, 19, 1615–1619, doi:10.3762/bjoc.19.118

• substrates. a) Substrate 7, reagents and conditions: 1) neat (5 equiv 5), 24 h; 2) Boc2O, NaHCO3, EtOH, ultrasound, 1 h, 88% (2 steps); 3) AcOH, hν (360 nm), 6 h, 74%. b) Substrate 9, reagents and conditions: 1) 11 (2 equiv), EtOAc, 23 °C, 1 h; 2) Boc2O, NaHCO3, EtOH, ultrasound, 23 °C, 1 h, 68% (2 steps); 3

C–H bond functionalization: recent discoveries and future directions

• Indranil Chatterjee

Beilstein J. Org. Chem. 2023, 19, 1568–1569, doi:10.3762/bjoc.19.114

• techniques. Some energy-economic reactors such as ball mill, microwave, ultrasound and, most importantly, flow reactors have also evolved towards a more sustainable future. To showcase the modern approaches in this domain, this thematic issue in the Beilstein Journal of Organic Chemistry gathers recent

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

• reaction of benzofuranone and aldehydes in good to excellent yields in a few minutes under ultrasound irradiation. Results and Discussion As a part of our ongoing research in DES chemistry, we were mainly interested in the conditions reported by Detsi [20], and attempted to apply them for rhodanine

Clauson–Kaas pyrrole synthesis using diverse catalysts: a transition from conventional to greener approach

• Dileep Kumar Singh and
• Rajesh Kumar

Beilstein J. Org. Chem. 2023, 19, 928–955, doi:10.3762/bjoc.19.71

• amines 50 were reacted with 2,5-DMTHF (2) in 5 mol % Bi(NO3)3·5H2O in solvent-free conditions under ultrasound irradiation at room temperature. The main advantages of this procedure are its simple isolation process, excellent product yield without using expensive or sensitive solvents and reagents

Continuous flow synthesis of 6-monoamino-6-monodeoxy-β-cyclodextrin

• János Máté Orosz,
• Dóra Ujj,
• Petr Kasal,
• Gábor Benkovics and
• Erika Bálint

Beilstein J. Org. Chem. 2023, 19, 294–302, doi:10.3762/bjoc.19.25

• efficient reaction used so far for the selective monofunctionalization of CDs [1]. Besides traditional synthetic methods, alternative techniques, such as ultrasound and microwave irradiation [21], as well as mechanosynthesis [22][23] for the functionalizations, such as tosylation or azidation of CDs have

Polymer and small molecule mechanochemistry: closer than ever

• José G. Hernández

Beilstein J. Org. Chem. 2022, 18, 1225–1235, doi:10.3762/bjoc.18.128

• ). Importantly, the BMPF mechanophore was also proven to be thermally stable up to 110 °C, which supports the conclusion that the mechanical force caused by the grinding was responsible for the activation of the BMPF mechanophores [28]. Comparative studies between ultrasound and ball milling have also

• [32], among others [33][34]. Therefore, it has been clearly demonstrated that pulsed ultrasound-based, grinding and ball milling techniques are competent in activating polymeric materials and, more importantly, that sometimes the apparent disparity between both approaches can actually lead to

• response to applied mechanical stress, and thus they could well be considered as force-reactive functional units (i.e., a new class of mechanophores) [52]. Interestingly, techniques based on ultrasound and ball milling have recently been used to activate piezoelectric materials, hinting at the similarities

A Streptomyces P450 enzyme dimerizes isoflavones from plants

• Run-Zhou Liu,
• Shanchong Chen and
• Lihan Zhang

Beilstein J. Org. Chem. 2022, 18, 1107–1115, doi:10.3762/bjoc.18.113

• mL MeOH was added and the mixture was treated with ultrasound for 15 min. After centrifugation, the supernatant was directly analyzed by HPLC following analytical method A. Chemical genetics experiments All samples involved in inhibition experiments were set up using 100 mL flasks containing 20 mL

• ISP-2 medium, 0.02 mg/mL daidzein (4), and the P450 inhibitor, by 1% inoculation from the above seed culture. On the 9th day, 0.5 mL of medium from each sample was taken and freeze-dried. Then, 0.2 mL MeOH was added, and the mixture was treated with ultrasound for 15 min. After centrifugation, the

First example of organocatalysis by cathodic N-heterocyclic carbene generation and accumulation using a divided electrochemical flow cell

• Daniele Rocco,
• Ana A. Folgueiras-Amador,
• Richard C. D. Brown and
• Marta Feroci

Beilstein J. Org. Chem. 2022, 18, 979–990, doi:10.3762/bjoc.18.98

• was added to the catholyte and the mixture was left under ultrasound irradiation for 30 minutes. The solvent was removed under reduced pressure and the residue was purified by column chromatography on silica gel. The first experiment (Table 1, entry 1) was carried out using stainless steel as cathode

• to the catholyte. The mixture was left under ultrasound irradiation for 30 minutes. The solvent was removed under reduced pressure and the residue was purified by column chromatography on silica gel (petroleum ether/ethyl acetate 7:3), affording the corresponding pure 1a as an off-white solid. 1

Complementarity of solution and solid state mechanochemical reaction conditions demonstrated by 1,2-debromination of tricyclic imides

• Petar Štrbac and
• Davor Margetić

Beilstein J. Org. Chem. 2022, 18, 746–753, doi:10.3762/bjoc.18.75

• ), even with the agitation by ultrasound (Table 1, entry 22). The ratios of side-products vary depending on the reaction conditions (Table S1, Supporting Information File 1). The endo-product 15 was dominant in the neat grinding experiment (Table 1, entry 1), whereas phthalimide 16 dominates when NaCl was

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

• ultrasound irradiation, obtaining quantitative yields when compared to the mechanical stirring procedure, thus demonstrating the best efficiency of the method [103]. In 2002, Arai and co-workers reported studies involving epoxidation reactions of menadione (10) using H2O2 as oxidant and a chiral salt derived

• a quantitative yield. Still about reduction reactions, Niemczyk and Van Arnum described a green methodology for reduction of menadione (10), during the pegylation of 14 to improving the solubility of the studied compounds [118]. The authors reduced 10 with sodium dithionite under ultrasound

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

• were harvested by centrifugation (4,000g, 20 min), re-suspended in lysis buffer (20 Mm Tris/HCl, pH 8.0, EDTA-free protease inhibitor cocktail tablet, 0.02 mg/mL DNaseI). Cell lysis was performed by sonication on ice. Cells were exposed to Amplitude microns of ultrasound every 20 seconds for 10 minutes

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

• of green chemistry [21]. The application of ultrasound in “traditional” reactions results in a lower reaction time, higher conversion, and simpler methodology and is termed sonochemistry. Ultrasonication is a modern trend in synthetic chemistry that supports the objective of green chemistry, namely

The PIFA-initiated oxidative cyclization of 2-(3-butenyl)quinazolin-4(3H)-ones – an efficient approach to 1-(hydroxymethyl)-2,3-dihydropyrrolo[1,2-a]quinazolin-5(1H)-ones

• Alla I. Vaskevych,
• Nataliia O. Savinchuk,
• Ruslan I. Vaskevych,
• Eduard B. Rusanov,
• Oleksandr O. Grygorenko and
• Mykhailo V. Vovk

Beilstein J. Org. Chem. 2021, 17, 2787–2794, doi:10.3762/bjoc.17.189

• - or ultrasound-assisted reaction of 2-aminobenzonitrile and alkenoyl chlorides [56]. We have found that substrates 7 can be obtained efficiently by a two-step reaction sequence commencing from acylation of anthranilamides 8 with α-allylacetyl chloride 9 leading to benzamides 10. These intermediates

Adjusting the length of supramolecular polymer bottlebrushes by top-down approaches

• Tobias Klein,
• Franka V. Gruschwitz,
• Maren T. Kuchenbrod,
• Ivo Nischang,
• Stephanie Hoeppener and
• Johannes C. Brendel

Beilstein J. Org. Chem. 2021, 17, 2621–2628, doi:10.3762/bjoc.17.175

• 2,500 rpm did not significantly change the observed distributions compared to 10 min treatment (Figure S13, Supporting Information File 1). For comparison to more established techniques, we tested the impact of US on the same fibers. Initial tests on treating fibers within an ultrasound bath (≈11.5 W⋅L

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

Synthetic accesses to biguanide compounds

• Oleksandr Grytsai,
• Cyril Ronco and
• Rachid Benhida

Beilstein J. Org. Chem. 2021, 17, 1001–1040, doi:10.3762/bjoc.17.82

• pressure and ultrasound sonication (Scheme 40). Microwave irradiation proved to be the most efficient conditions with regard to reaction time and conversion. Moderate to high isolated yields (43–95%) were obtained depending on the carbodiimides, the elevated temperatures sometimes required led to the