Transition-metal-catalyzed C–H bond activation as a sustainable strategy for the synthesis of fluorinated molecules: an overview

• Louis Monsigny,
• Floriane Doche and
• Tatiana Besset

Beilstein J. Org. Chem. 2023, 19, 448–473, doi:10.3762/bjoc.19.35

• acrylamide derivatives [140]. Using the same directing group, a panel of α-arylacrylamide derivatives 39a–f was successfully functionalized with a high Z-selectivity (yields up to 98%, Scheme 18). Both, thermal reaction conditions (DMSO at 70 °C for 16 h) and microwave irradiation (100 °C using microwaves in

CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview

• Dileep Kumar Singh

Beilstein J. Org. Chem. 2023, 19, 349–379, doi:10.3762/bjoc.19.29

• , Locos et al. [31] successfully used the Cu(I)-catalyzed click reaction to synthesize triazole-linked glycoporphyrins under microwave conditions. At first, the glycoporphyrins 43a,b were synthesized in good yields by the reaction between zinc(II) 5-(4-azidophenyl)-10,15,20-triphenylporphyrin (39a) and

• microwave conditions as described in Scheme 12. After the successful synthesis of porphyrins 63 and 66b, their corresponding rhenium complexes 64a and 67a were prepared in good yields by using [Re(CO)3Br3][NEt4]2 at 65 °C in 2 hours. In addition to these, the radiolabeled products 64b and 67b were also

• conjugates (99a–d, 103a,b) were utilized for the preparation of porphyrin-fullerene dyads 100a–d and 104a,b in 30–70% yield by the reaction with C60 and sarcosine in toluene under microwave conditions. The photophysical and computational studies of these ZnP-Tri-C60 conjugates revealed that the 1,2,3

Group 13 exchange and transborylation in catalysis

• Dominic R. Willcox and
• Stephen P. Thomas

Beilstein J. Org. Chem. 2023, 19, 325–348, doi:10.3762/bjoc.19.28

• esters, lactones, and carbonates with HBpin under microwave irradiation (Scheme 13) [57]. When HBpin and boric acid were reacted together, BH3-coordinated HBpin and O(Bpin)2 were detected by 11B NMR spectroscopy. Supported by computational analysis and single-turnover experiments, the reaction was

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

Strategies to access the [5-8] bicyclic core encountered in the sesquiterpene, diterpene and sesterterpene series

• Cécile Alleman,
• Charlène Gadais,
• Laurent Legentil and
• François-Hugues Porée

Beilstein J. Org. Chem. 2023, 19, 245–281, doi:10.3762/bjoc.19.23

Preparation of β-cyclodextrin-based dimers with selectively methylated rims and their use for solubilization of tetracene

• Konstantin Lebedinskiy,
• Volodymyr Lobaz and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2022, 18, 1596–1606, doi:10.3762/bjoc.18.170

• catalytical amounts (0.02 equiv) [27] to semi-equivalent [12]. Optimal conditions for a click reaction are a subject to discovery in every case, because temperature, microwave or ultrasonic irradiation, and type of catalyst strongly influence the reaction time and yields. In the preparation of dimer 4, the

An alternative C–P cross-coupling route for the synthesis of novel V-shaped aryldiphosphonic acids

• Stephen J. I. Shearan,
• Enrico Andreoli and
• Marco Taddei

Beilstein J. Org. Chem. 2022, 18, 1518–1523, doi:10.3762/bjoc.18.160

• of us, was limited to 0.543 g (1 mmol) of substrate. Scale up of this protocol was not attempted, but it might become problematic due to issues with microwave penetration in a medium that contains a strong absorber, such as the Ni catalytic complex. In this work, we have employed either 5.0 g (15.3

• phosphonate syntheses with the alternative method proposed in this work. The microwave-assisted method made use of a pressure-resistant vessel due to considerable pressure buildup (≈ 10 bar), while the other methods were run under reflux conditions. Supporting Information Supporting Information File 348: NMR

Cyclometalated iridium complexes-catalyzed acceptorless dehydrogenative coupling reaction: construction of quinoline derivatives and evaluation of their antimicrobial activities

• Hongling Shui,
• Yuhong Zhong,
• Renshi Luo,
• Zhanyi Zhang,
• Jiuzhong Huang,
• Ping Yang and
• Nianhua Luo

Beilstein J. Org. Chem. 2022, 18, 1507–1517, doi:10.3762/bjoc.18.159

• . In addition, Aravinda's group [11] prepared 3-(1,3-dioxolan-2-yl)benzo[h]quinolines containing thiol and selenol groups in one pot by microwave irradiation, and tested the antibacterial activity of the compounds. The results showed that the antibacterial effect of some compounds was better than

Modular synthesis of 2-furyl carbinols from 3-benzyldimethylsilylfurfural platforms relying on oxygen-assisted C–Si bond functionalization

• Sebastien Curpanen,
• Per Reichert,
• Gabriele Lupidi,
• Giovanni Poli,
• Julie Oble and
• Alejandro Perez-Luna

Beilstein J. Org. Chem. 2022, 18, 1256–1263, doi:10.3762/bjoc.18.131

• . Procedure for the Cu-catalyzed allylation and methylation of C3-benzyldimethylsilyl-substituted 2-furyl carbinols (preparation of compounds 21 and 23–28) CuI⋅PPh3 [37] (20 or 120 mol %) was introduced to a flame-dried microwave vial, which was then placed under an argon atmosphere and sealed. In a Schlenk

Mechanochemical bottom-up synthesis of phosphorus-linked, heptazine-based carbon nitrides using sodium phosphide

• Blaine G. Fiss,
• Georgia Douglas,
• Michael Ferguson,
• Jorge Becerra,
• Jesus Valdez,
• Trong-On Do,
• Tomislav Friščić and
• Audrey Moores

Beilstein J. Org. Chem. 2022, 18, 1203–1209, doi:10.3762/bjoc.18.125

• minimize the bandgap of these metal-free photocatalysts, as well as improve their overall stability. Traditional routes to incorporate phosphorus have relied on high-temperature [7] or microwave [8] syntheses, and often proceed through the introduction of a phosphorus atom within the heptazine ring, which

Derivatives of benzo-1,4-thiazine-3-carboxylic acid and the corresponding amino acid conjugates

• Péter Kisszékelyi,
• Tibor Peňaška,
• Klára Stankovianska,
• Mária Mečiarová and
• Radovan Šebesta

Beilstein J. Org. Chem. 2022, 18, 1195–1202, doi:10.3762/bjoc.18.124

• 1,3-dicarbonyl compounds using a catalytic amount of hydrazine hydrate without solvent in a short reaction time (10 min) [14]. Reactions of 2-aminothiophenols with β-keto esters and β-diketones under microwave irradiation (MWI) using basic alumina as heterogeneous catalyst without solvent afforded 4H

Introducing a new 7-ring fused diindenone-dithieno[3,2-b:2',3'-d]thiophene unit as a promising component for organic semiconductor materials

• Valentin H. K. Fell,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Eman J. Hussien and
• Peter J. Skabara

Beilstein J. Org. Chem. 2022, 18, 944–955, doi:10.3762/bjoc.18.94

• very sensitive to changes in concentration, equivalents, amounts of reagents, and temperature. Running the reaction under anhydrous conditions, either conventionally [45] or in the microwave [46] did not improve the outcome. The optimised reaction and purification parameters can be found in Supporting

Synthesis of odorants in flow and their applications in perfumery

• Merlin Kleoff,
• Paul Kiler and
• Philipp Heretsch

Beilstein J. Org. Chem. 2022, 18, 754–768, doi:10.3762/bjoc.18.76

• first developed on small scale under microwave batch conditions to reach short reaction times of 1–10 min and subsequently translated to scalable flow processes [24]. While raspberries have a fruity and “berry” scent which is typically associated with the color red, the scent of citrus fruits is placed

Inductive heating and flow chemistry – a perfect synergy of emerging enabling technologies

• Conrad Kuhwald,
• Sibel Türkhan and
• Andreas Kirschning

Beilstein J. Org. Chem. 2022, 18, 688–706, doi:10.3762/bjoc.18.70

• synthesis; nanoparticles; Introduction Several decades ago, inductive heating was introduced as an indirect technique in various applications, including industrial manufacturing, synthetic chemistry [1][2][3], and medicine (Figure 1) [4][5][6][7]. Compared to microwave heating [8][9], the other major

• convection across a surface. Compared to heating under microwave irradiation, the system does not need to be encased for safety reasons. Inductive heating of materials is extremely fast with the best determined power transfer value of all heating technologies [10]. It has therefore found wide industrial

• mesoflow technology and indirect heating 3.1 Microwave-accelerated reactions under flow conditions Reactions that take 20 minutes or longer under classical batch conditions can be accelerated considerably under continuous flow conditions by rapid heating, because flow chemistry usually involves the use of

Synthesis of sulfur karrikin bioisosteres as potential neuroprotectives

• Martin Pošta,
• Václav Zima,
• Lenka Poštová Slavětínská,
• Marika Matoušová and
• Petr Beier

Beilstein J. Org. Chem. 2022, 18, 549–554, doi:10.3762/bjoc.18.57

• (14), respectively, following a published procedure [21][23], while karrikin KAR2 (2) was synthesized from ᴅ-xylose [24]. The conversion of karrikins 1–4 to the corresponding C2 thiones 9–12 was accomplished using microwave-assisted heating with Lawesson’s reagent and hexamethyldisiloxane (HMDO

• ][31], microwave heating did not improve the yields; therefore, conventional heating was used in our case. Generally, 5 is the most reactive among the substrates and the experiments proved that only 5 and not 13 or 14 can be partially converted to thiopyranthione 6b in the presence of P4S10 without

• derivatives 27–30 were prepared from 8, 20, 21, and 26 using microwave heating with Lawesson’s reagent and HMDO (Scheme 6). Thionation provided the title compounds in good to high yields. Biochemical study – AchE inhibition The compounds were further tested for their ability to inhibit AChE in vitro [24

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

Synthesis of 5-unsubstituted dihydropyrimidinone-4-carboxylates from deep eutectic mixtures

• Sangram Gore,
• Sundarababu Baskaran and
• Burkhard König

Beilstein J. Org. Chem. 2022, 18, 331–336, doi:10.3762/bjoc.18.37

• -unsubstituted 3,4-dihydropyrimidinone-4-carboxylate derivatives by employing oxalacetic acid as a β-ketoester equivalent in the presence of TFA via a Biginelli reaction [23]. Lam and Fang reported the same synthesis under microwave conditions [24]. Very recently, Kambappa and co-workers reported a one-pot

Recent developments and trends in the iron- and cobalt-catalyzed Sonogashira reactions

• Surendran Amrutha,
• Sankaran Radhika and
• Gopinathan Anilkumar

Beilstein J. Org. Chem. 2022, 18, 262–285, doi:10.3762/bjoc.18.31

• model reaction without any external ligand and required 20 h for completion. However, the same reaction under microwave irradiation was complete within 2.5 h. The product was obtained with an excellent yield of 95% by the utilization of Fe(III) acetylacetonate and CuI as the catalyst. Among several iron

• systems utilizing an iron catalyst under microwave irradiation has been reported [34]. N-Arylated azaindoles were prepared by Sonogashira coupling followed by cyclization. The Sonogashira coupling of 2-arylamino-3-iodopyridines with terminal acetylenes followed by cyclization afforded the 2-N-arylated 7

• -azaindole derivatives under microwave irradiation that helps to reduce the reaction time and minimizes side product formation. Co-catalyzed Sonogashira cross-coupling reactions Nanoparticle-based protocols The advantages of using immobilized catalysts include the possibility of the catalyst to be easily

Synthesis of novel [1,2,4]triazolo[1,5-b][1,2,4,5]tetrazines and investigation of their fungistatic activity

• Anna V. Korotina,
• Svetlana G. Tolshchina,
• Rashida I. Ishmetova,
• Natalya P. Evstigneeva,
• Natalya A. Gerasimova,
• Natalya V. Zilberberg,
• Nikolay V. Kungurov,
• Gennady L. Rusinov,
• Oleg N. Chupakhin and
• Valery N. Charushin

Beilstein J. Org. Chem. 2022, 18, 243–250, doi:10.3762/bjoc.18.29

• can also be used as an oxidant for the oxidation of benzamidine derivatives 2b,c in acetonitrile under microwave irradiation. Along with the cyclization reaction, bromination of the pyrazole ring proved to occur at position C(4) to give the products 3j,k, as evidenced by disappearance of the

• formation of difficult-to-separate reaction mixtures with a low content of the target products 3a,b,g, which could not be isolated in a pure form. Heating of tetrazines 2 with N-bromosuccinimide in refluxing acetonitrile without microwave irradiation made it possible to obtain the product 3j in a low yield

Efficient synthesis of ethyl 2-(oxazolin-2-yl)alkanoates via ethoxycarbonylketene-induced electrophilic ring expansion of aziridines

• Yelong Lei and
• Jiaxi Xu

Beilstein J. Org. Chem. 2022, 18, 70–76, doi:10.3762/bjoc.18.6

• alkoxycarbonylketenes, which undergo an electrophilic ring expansion with aziridines to afford alkyl 2-(oxazolin-2-yl)alkanoates in good to excellent yields under microwave heating. The method is a convenient and clean reaction without any activators and catalysts and can be also applied in the synthesis of 2-(oxazolin

• microwave heating, affording the desired product 3aa in 41% yield with remaining starting materials 1a and 2a (Table 1, entry 1). The reaction was further conducted at elevated temperatures 120 °C, 130 °C, and 140 °C, giving the product 3aa in 64%, 68%, and 70%, respectively (Table 1, entries 2–4). Similar

• solubility to all substrates than toluene, the optimal reaction conditions were selected as: diazo ester 1a (0.36 mmol) and 2a (0.3 mmol) in DCE (1 mL) were heated at 130 °C for 20 min with microwave heating. With the optimal reaction conditions in hand, we evaluated the scopes and generalities of both diazo

Recent advances and perspectives in ruthenium-catalyzed cyanation reactions

• Thaipparambil Aneeja,
• Cheriya Mukkolakkal Abdulla Afsina,
• Padinjare Veetil Saranya and
• Gopinathan Anilkumar

Beilstein J. Org. Chem. 2022, 18, 37–52, doi:10.3762/bjoc.18.4

• and earth abundant characteristics. Moreover, much greener methodologies like microwave-assisted cyanation reactions also received much attention in recent times [21]. The cyanation can be carried out using electrophilic and nucleophilic cyanating agents [22]. Usually a cyanation is accomplished via

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

Efficient N-arylation of 4-chloroquinazolines en route to novel 4-anilinoquinazolines as potential anticancer agents

• Rodolfo H. V. Nishimura,
• Thiago dos Santos,
• Valter E. Murie,
• Luciana C. Furtado,
• Leticia V. Costa-Lotufo and
• Giuliano C. Clososki

Beilstein J. Org. Chem. 2021, 17, 2968–2975, doi:10.3762/bjoc.17.206

• . Lineu Prestes 1524, 05508-900 São Paulo-SP, Brazil 10.3762/bjoc.17.206 Abstract Microwave-mediated N-arylation of 4-chloroquinazolines in THF/H2O rapidly and efficiently afforded a library of novel 6-halo-2-phenyl-substituted 4-anilinoquinazolines. The methodology was compatible with numerous ortho

• -anilinoquinazoline; anticancer agents; N-arylation; 4-chloroquinazoline; microwave irradiation; Introduction N-Heterocyclic compounds are commonly present in pharmaceuticals, bioactive natural products, agrochemicals, and synthetic drugs [1][2]. Quinazoline, a benzo-fused N-heterocyclic framework (benzo-1,3-diazine

• ]. These limitations can be overcome by using microwave irradiation [12][13][18][19][20], which promotes fast and efficient anilination reactions when a wide range of anilines bearing both electron-donating and electron-withdrawing groups are employed as nucleophiles (Scheme 1b) [12][13]. Moreover, 4

Selective sulfonylation and isonitrilation of para-quinone methides employing TosMIC as a source of sulfonyl group or isonitrile group

• Chuanhua Qu,
• Run Huang,
• Yong Li,
• Tong Liu,
• Yuan Chen and
• Guiting Song

Beilstein J. Org. Chem. 2021, 17, 2822–2831, doi:10.3762/bjoc.17.193

• treated with 20 mol % Ag2CO3 in THF in the presence of Cs2CO3 at 90 °C under microwave irradiation for 10 min, fortunately, the sulfonylated diarylmethane product 3a was isolated in 36% yield (Table 1, entry 2). When ZnI2 or Cu(OAc)2 was used instead of Ag2CO3, we found that the yield of 3a catalyzed by

• the reaction mixture was heated under microwave irradiation at 90 °C for 10 min and monitored by TLC until starting material was consumed. Then, the reaction mixture was concentrated under reduced pressure followed by column chromatography over silica gel using petroleum/EtOAc (0 to 10%) as eluent to

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

• unsaturated moieties. The known literature exceptions included synthesis of 2-alkynylquinazolines via acylation of anthranilamides with alkynylcarboxylic acids and further cyclocondensation under alkaline conditions [36], as well as formation of 2-alkenyl counterparts by a one-pot Yb(OTf)3-catalyzed microwave