Innovative synthesis of drug-like molecules using tetrazole as core building blocks

• Jingyao Li,
• Ajay L. Chandgude,
• Qiang Zheng and
• Alexander Dömling

Beilstein J. Org. Chem. 2024, 20, 950–958, doi:10.3762/bjoc.20.85

• developed building block approach, we decided to incorporate an oxo-tetrazole into an Ugi four-component reaction, the most studied and versatile MCR in organic synthesis and drug discovery [31][32]. Despite tremendous exploration, finding novel substrates or bioisosteres as a starting material in the Ugi

One-pot Ugi-azide and Heck reactions for the synthesis of heterocyclic systems containing tetrazole and 1,2,3,4-tetrahydroisoquinoline

• Jiawei Niu,
• Yuhui Wang,
• Shenghu Yan,
• Yue Zhang,
• Xiaoming Ma,
• Qiang Zhang and
• Wei Zhang

Beilstein J. Org. Chem. 2024, 20, 912–920, doi:10.3762/bjoc.20.81

• schistosomiasis [22][23][24][25]. The combination of the privileged heterocycles tetrazole and tetrahydroisoquinoline in one molecule generates new molecules which could have biological activities. A standard Ugi four-component reaction (Ugi-4CR) of an aldehyde, amine, isocyanide, and a carboxylic acid produces

• highly diverse peptidic structures A with up to four points of substitution (Scheme 1) [26][27]. By replacing the carboxylic acid with a nucleophilic azide reagent XN3 (generally TMSN3), the Ugi-azide four-component reaction (UA-4CR) of an aldehyde, amine, isocyanide, and azide gives 1,5-disubstituted 1H

• . The initial Ugi-azide four-component reaction constructs the tetrazole motif while the subsequent intramolecular Heck reaction assembles the tetrahydroisoquinoline. The one-pot reaction avoids the intermediate purification which has favorable PASE in the synthesis of heterocyclic compounds

Catalytic multi-step domino and one-pot reactions

• Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2024, 20, 254–256, doi:10.3762/bjoc.20.25

• acetaldehyde dimethyl acetal as a masked form of acetaldehyde, which is hydrolyzed in situ, allowing for a higher product yield and fewer byproducts [15]. The group of Müller describes an elegant consecutive four-component reaction involving an alkynylation–cyclization–iodination–alkylation sequence toward

Decarboxylative 1,3-dipolar cycloaddition of amino acids for the synthesis of heterocyclic compounds

• Xiaofeng Zhang,
• Xiaoming Ma and
• Wei Zhang

Beilstein J. Org. Chem. 2023, 19, 1677–1693, doi:10.3762/bjoc.19.123

• pseudo-four-component reaction for the synthesis of tetrahydropyrrolothiazole derivatives. The reaction of cysteine with two equiv of arylaldehydes and one equiv of maleimides in EtOH at 90 °C for 12 h afforded tetrahydropyrrolothiazoles 29 in 66–79% yields with up to 7:1 dr (Scheme 17) [76]. Using

• ]isoquinolines. Pseudo-four-component reaction for the synthesis of tetrahydropyrrolothiazoles 29 and 30 (>4:1 dr). One-pot two-step synthesis of spirooxindole-pyrrolothiazoles 31 (>4:1 dr). Acknowledgements We would like to thank all our co-workers who worked on the research projects highlighted in this paper

Consecutive four-component synthesis of trisubstituted 3-iodoindoles by an alkynylation–cyclization–iodination–alkylation sequence

• Nadia Ledermann,
• Alae-Eddine Moubsit and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2023, 19, 1379–1385, doi:10.3762/bjoc.19.99

• generated by a consecutive four-component reaction starting from ortho-haloanilines, terminal alkynes, N-iodosuccinimide, and alkyl halides in yields of 11–69%. Initiated by a copper-free alkynylation, followed by a base-catalyzed cyclizive indole formation, electrophilic iodination, and finally

• prior to terminal alkylation could provide a straightforward entry to trisubstituted 3-iodoindoles, which are valuable building blocks for accessing highly decorated (aza)indoles (Scheme 1). Here, we report the concise consecutive four-component synthesis of trisubstituted 3-iodoindoles. Results and

• to directly employ these standard conditions to the sequence of ortho-haloanilines 1, terminal alkynes 2, N-iodosuccinimide (3), and alkyl halides 4 to screen the scope of the one-pot synthesis of trisubstituted 3-iodoindoles 5 in a consecutive four-component fashion (Scheme 2). The sequence

Selective construction of dispiro[indoline-3,2'-quinoline-3',3''-indoline] and dispiro[indoline-3,2'-pyrrole-3',3''-indoline] via three-component reaction

• Ziying Xiao,
• Fengshun Xu,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1234–1242, doi:10.3762/bjoc.19.91

• multicomponent reactions have been successfully developed to construct multifunctionalized or polycyclic spirooxindoles. For example, Zhang successfully developed a recyclable bifunctional cinchona/thiourea-catalyzed four-component Michael/Mannich cyclization sequence for the asymmetric synthesis of

Unravelling a trichloroacetic acid-catalyzed cascade access to benzo[f]chromeno[2,3-h]quinoxalinoporphyrins

• Chandra Sekhar Tekuri,
• Pargat Singh and
• Mahendra Nath

Beilstein J. Org. Chem. 2023, 19, 1216–1224, doi:10.3762/bjoc.19.89

• Chandra Sekhar Tekuri Pargat Singh Mahendra Nath Department of Chemistry, Faculty of Science, University of Delhi, Delhi 110 007, India 10.3762/bjoc.19.89 Abstract A facile one-pot four-component synthetic methodology is evolved to construct novel copper(II) benzo[f]chromeno[2,3-h

• present study discloses an easy and first synthetic approach to build highly π-conjugated copper(II) benzo[f]chromeno[2,3-h]quinoxalinoporphyrins through a trichloroacetic acid-catalyzed one-pot four-component reaction of 2,3-diamino-5,10,15,20-tetraarylporphyrins, 2-hydroxynaphthalene-1,4-dione, aromatic

• ]chromeno[2,3-h]quinoxalinoporphyrins 3–8. For the optimization of the reaction conditions, a model four-component reaction of copper(II) 2,3-diamino-5,10,15,20-tetra(p-tolyl)porphyrin with 2-hydroxynaphthalene-1,4-dione (2), benzaldehyde and dimedone was carried out in the presence of 20 mol % p

Synthesis of imidazo[1,2-a]pyridine-containing peptidomimetics by tandem of Groebke–Blackburn–Bienaymé and Ugi reactions

• Oleksandr V. Kolomiiets,
• Alexander V. Tsygankov,
• Maryna N. Kornet,
• Aleksander A. Brazhko,
• Vladimir I. Musatov and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2023, 19, 727–735, doi:10.3762/bjoc.19.53

• 24 hours at room temperature in DMF with catalytic amounts of HClO4. The yield of compound 4a in this case was 76%. Then new heterocyclic acids were used as reagents for the Ugi four-component reaction. Due to the rather low solubility of the acids in methanol, it was necessary to increase the

• heterocyclic acid 8a was obtained by a three-component reaction of 2-amino-5-chloropyridine (1a), 4-formylbenzoic acid (5f), and tert-butyl isocyanide (3a) according to the procedure described above (Scheme 3). In another step, we attempted to introduce the acid 8a into the Ugi four-component reaction with 4

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

• Péter Kisszékelyi and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

• diastereomers were detected (Scheme 9A). Furthermore, the authors have also demonstrated a four-component coupling reaction: by simply increasing the amount of the organolithium reagent (2.05 equiv) used for the activation of the Zn enolate, β-hydroxyketones 40 were gained via 1,2-addition of the zincate

One-pot double annulations to confer diastereoselective spirooxindolepyrrolothiazoles

• Juan Lu,
• Bin Yao,
• Desheng Zhan,
• Zhuo Sun,
• Yun Ji and
• Xiaofeng Zhang

Beilstein J. Org. Chem. 2022, 18, 1607–1616, doi:10.3762/bjoc.18.171

• 10.3762/bjoc.18.171 Abstract A novel four-component reaction in one pot as an atom- and step-economic process was developed to synthesize diastereoselectively spirooxindolepyrrolothiazoles through sequential N,S-acetalation of aldehydes with cysteine and decarboxylative [3 + 2] cycloaddition with olefinic

• PASE reactions of making spirooxindolepyrrolothiazoles are even more rare, which only involves three-component reactions with isatins and thioproline (Scheme 2A and 2B) [75][76]. Four-component double annulations through 2-substituted thioprolines formed in N,S-acetalation of aldehyde and cysteine was

• results using ᴅ- and ʟ-cysteine to synthesize compound 5a (Scheme 5). We conferred green chemistry metrics to evaluate the process efficiency of four-component reaction via comprehensive and quantitative calculation. The metrics analysis is carried out for the two-step synthesis with intermediate

Molecular diversity of the base-promoted reaction of phenacylmalononitriles with dialkyl but-2-ynedioates

• Hui Zheng,
• Ying Han,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2022, 18, 991–998, doi:10.3762/bjoc.18.99

• dialkyl but-2-ynedioate. Thus, a quasi-four-component reaction led to the final product. There are two chiral carbon atoms in the molecules, thus two diastereoisomers would be formed in the reaction. However, the 1H and 13C NMR spectra gave only one set of resonances for the characteristic groups, which

Copper-catalyzed multicomponent reactions for the efficient synthesis of diverse spirotetrahydrocarbazoles

• Shao-Cong Zhan,
• Ren-Jie Fang,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2022, 18, 796–808, doi:10.3762/bjoc.18.80

• Shao-Cong Zhan Ren-Jie Fang Jing Sun Chao-Guo Yan College of Chemistry & Chemical Engineering, Yangzhou University, Yangzhou 225002, China 10.3762/bjoc.18.80 Abstract In the presence of copper sulfate, three- or four-component reactions of 2-methylindole, aromatic aldehydes and various cyclic

• dienophiles, 5-arylidene-1,3-dimethylbarbituric acids, could be in situ generated by aromatic aldehydes and 1,3-dimethylbarbituric acid under the standard conditions. Therefore, the four-component reaction was carried out by using two molecular aromatic aldehydes, 1,3- dimethylbarbituric acid and 2

• '-indolines] 2a–h, in which the two phenyl groups exist in cis-position. This result clearly indicated that this reaction has a similar outcome of stereochemistry. Based on the success of the four-component reaction through in situ generation of dienes and dienophiles, we further considered whether more

Heteroleptic metallosupramolecular aggregates/complexation for supramolecular catalysis

• Prodip Howlader and
• Michael Schmittel

Beilstein J. Org. Chem. 2022, 18, 597–630, doi:10.3762/bjoc.18.62

• = 24 kHz (at 298 K). A similar exchange process was observed in the four-component rotors [90] developed along two orthogonal self-sorting motifs (HETPYP = Npy → [Cu(phenAr2)]+ and NDABCO → ZnPor interactions). Again, the synthetic approach is a straightforward multicomponent self-sorting assembly

• , thermodynamic stabilization quantitatively drives the reaction to the hetero-assembly 59, simply by mixing the components in the correct stoichiometric ratio (Figure 13). Various nanorotor assemblies are possible by this approach. The dynamics of the four-component rotor 59 = [Cu2(55)(57)(60)]2+ cannot be

• ) through nanomechanical motion. Recently, the suitability of the four-component rotors to act as catalysts in various click reactions was investigated having a look at nanorotors [Cu2(55)(60)(X)]2+ (with X = 62, 63 or 64), revealing an unexpected correlation between their rotational speed and catalytic

Iron-catalyzed domino coupling reactions of π-systems

• Austin Pounder and
• William Tam

Beilstein J. Org. Chem. 2021, 17, 2848–2893, doi:10.3762/bjoc.17.196

• a four-component radical dual difunctionalization and ordered assembly of two chemically distinct alkenes 114/115, aldehyde 65, and tert-butyl peroxide (Scheme 23) [108]. In order to selectively couple one alkene to another, without the formation of oligomers, the authors utilized the different

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

• mechanistically similar to the Hantzsch pyridine synthesis is the Guareschi type-IV pyridine synthesis, first reported in 1897 [7] and involving the four-component condensation of ammonia, a carbonyl derivative, and two molecules of a cyanoacetic ester. The reaction affords 3,5-dicyanoglutarimides, known as

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

• Shivani Gulati,
• Stephy Elza John and
• Nagula Shankaraiah

Beilstein J. Org. Chem. 2021, 17, 819–865, doi:10.3762/bjoc.17.71

• exploring the MC-MWA reactions Jiang and co-workers [41] designed a microwave facilitated regioselective four-component domino reaction employing naphthyl- or anthracenylamine 10, aldehydes 5 and 2-hydroxy-1,4-naphthoquinone (11) in acetic acid for the construction of dibenzo[a,h]acridine-12,13(7H,14H

• azepinone 22 and exemplified a modified Ugi reaction (four-component reaction). The aldehyde and acid component of the Ugi reaction was functionalized on the same biaryl ring employing a Suzuki–Miyaura coupling. The authors advocated the use of microwave as it consistently increased the yield from 49% to 82

• ). Similarly, the same group extended the work by illustrating [51] a three and four-component microwave-assisted base and catalyst-free reaction for the synthesis of substituted spirooxindoles 40. The three-component reaction involved the reaction between substituted isatin 35, but-2-ynedioates 39 and amino

Effective microwave-assisted approach to 1,2,3-triazolobenzodiazepinones via tandem Ugi reaction/catalyst-free intramolecular azide–alkyne cycloaddition

• Maryna O. Mazur,
• Oleksii S. Zhelavskyi,
• Eugene M. Zviagin,
• Svitlana V. Shishkina,
• Vladimir I. Musatov,
• Maksim A. Kolosov,
• Elena H. Shvets,
• Anna Yu. Andryushchenko and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2021, 17, 678–687, doi:10.3762/bjoc.17.57

• to a large number of diverse heterocyclic compounds [10][11]. Over the past decade, several cases of using an Ugi four-component reaction (Ugi-4CR) in combination with intramolecular azide–alkyne cycloaddition (IAAC) for the synthesis of 1,2,3-triazolobenzodiazepines were reported [3][7][12][13][14

• conclusion, we have advanced the creation of a convenient tandem approach to potentially biologically active 1,2,3-triazolobenzodiazepinones. The developed synthetic procedure includes a four-component Ugi reaction followed by microwave-assisted intramolecular azide–alkyne cycloaddition and allows to build a

Synthetic strategies of phosphonodepsipeptides

• Jiaxi Xu

Beilstein J. Org. Chem. 2021, 17, 461–484, doi:10.3762/bjoc.17.41

• phosphonylation of hydroxy esters 2 with N-protected aminoalkylphosphonochloridates 3 (method I), reactions of N-protected aminoalkylphosphonic monoesters 4 with hydroxy esters 2 (method II) or with 1-(alkoxycarbonyl)alkyl halides or sulfonates 5 (method III), pseudo-four-component condensations (method IV), and

Using multiple self-sorting for switching functions in discrete multicomponent systems

• Amit Ghosh and
• Michael Schmittel

Beilstein J. Org. Chem. 2020, 16, 2831–2853, doi:10.3762/bjoc.16.233

• release of DABCO using a double self-sorting protocol [54]. Schmittel and co-workers reported on the three-component rectangle [Cu4(16)2(17)2]4+ (SelfSORT-I) that rearranged into the four-component sandwich complex [Cu2(16)(17)(18)]2+ (Figure 8) upon the addition of DABCO (SelfSORT-II). A full

• -assemble the four-component rotor [Cu2(79)(80)(18)]2+ that itself triggered the catalysis of a click reaction (81 + 46 → 82) as shown in Figure 22. In conclusion, the output of the AND gate regulated both the assembly of the multicomponent machinery and the catalytic output. Conclusion In conclusion, the

• . Some selected self-sorting outcomes and their qualitative and quantitative assessment. Illustration of an integrative vs a non-integrative self-sorting. The pH-driven four-component 2-fold completive self-sorting based on host–guest chemistry. (a) The monomers 5 and 6 and their H-bonding array. (b) The

Controlling the stereochemistry in 2-oxo-aldehyde-derived Ugi adducts through the cinchona alkaloid-promoted electrophilic fluorination

• Yuqing Wang,
• Gaigai Wang,
• Anatoly A. Peshkov,
• Ruwei Yao,
• Muhammad Hasan,
• Manzoor Zaman,
• Chao Liu,
• Stepan Kashtanov,
• Olga P. Pereshivko and
• Vsevolod A. Peshkov

Beilstein J. Org. Chem. 2020, 16, 1963–1973, doi:10.3762/bjoc.16.163

• -component Passerini [19][20][21][22] and four-component Ugi [23][24] reactions that rely on the ability of organic isocyanides to participate in the nucleophilic attack onto the carbonyl or imine group are among the most studied MCRs. Accordingly, a wide range of post-MCR transformations have been

• ], no general asymmetric protocol for the four-component mode has been developed until very recently. In 2018, Houk, Tan and co-workers described an efficient enantioselective procedure operating in the presence of catalytic amounts of chiral phosphoric acids (Table 2) [57]. Two synthetic protocols have

• structure of (S)-12e (slow enantiomer). Post-transformations of 2-oxo-aldehyde-derived Ugi adducts 8. Synthesis of 2-oxo-aldehyde-derived Ugi adducts. Asymmetric protocols for Passerini three-component reaction (P-3CR). Asymmetric protocols for Ugi four-component reaction (U-4CR) by Houk, Tan and co-workers

Palladium-catalyzed regio- and stereoselective synthesis of aryl and 3-indolyl-substituted 4-methylene-3,4-dihydroisoquinolin-1(2H)-ones

• Valeria Nori,
• Antonio Arcadi,
• Armando Carlone,
• Fabio Marinelli and
• Marco Chiarini

Beilstein J. Org. Chem. 2020, 16, 1084–1091, doi:10.3762/bjoc.16.95

• palladium-catalyzed regioselective cascade cyclization of propargylamides/coupling with ArB(OH)2 in dioxane/water, to give trisubstituted arylidene-isoquinolinones [44] was published. However, the Ugi four-component reaction used to construct the starting building blocks was limited to the preparation of

Microwave-assisted efficient and facile synthesis of tetramic acid derivatives via a one-pot post-Ugi cascade reaction

• Yong Li,
• Zheng Huang,
• Jia Xu,
• Yong Ding,
• Dian-Yong Tang,
• Jie Lei,
• Hong-yu Li,
• Zhong-Zhu Chen and
• Zhi-Gang Xu

Beilstein J. Org. Chem. 2020, 16, 663–669, doi:10.3762/bjoc.16.63

• medicinal chemistry. Multicomponent reactions (MCRs) [22][23][24] are emerging tools for assembling complex molecules in a rapid and efficient manner. The four-component Ugi reaction followed by a suitable post modification of [25][26] has become a popular research field for diversity-oriented synthesis [27

• [35][36][37]. These new processes improved the overall efficiency with shorter reaction times and lower costs of synthetic preparations, and minimized the amount of waste generated. In recent years, we used the Ugi four-component reaction as a main tool to generate nitrogen-containing heterocycles [38

Ultrasonic-assisted unusual four-component synthesis of 7-azolylamino-4,5,6,7-tetrahydroazolo[1,5-a]pyrimidines

• Yana I. Sakhno,
• Maryna V. Murlykina,
• Oleksandr I. Zbruyev,
• Anton V. Kozyryev,
• Svetlana V. Shishkina,
• Dmytro Sysoiev,
• Vladimir I. Musatov,
• Sergey M. Desenko and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2020, 16, 281–289, doi:10.3762/bjoc.16.27

• Republic 10.3762/bjoc.16.27 Abstract Four-component reactions of 3-amino-1,2,4-triazole or 5-amino-1H-pyrazole-4-carbonitrile with aromatic aldehydes and pyruvic acid or its esters under ultrasonication were studied. Unusual for such a reaction type, a cascade of elementary stages led to the formation of

• -pyrazole-4-carbonitrile with aromatic aldehydes and pyruvic acid or its esters under ultrasonication led to the formation of 4,5,6,7-tetrahydroazolo[1,5-a]pyrimidines 4a–u (Scheme 4) containing an azolylamino substituent in the 7-position via an unusual pseudo four-component reaction, rather than two

• -aminopyrazoles bearing an electron-withdrawing substituent in the 4-position, such as a carbonitrile group, often behave similar to 3-amino-1,2,4-triazole; therefore, we studied the latter under the same reaction conditions. We showed that the pseudo four-component heterocyclization of two equivalents of 3-amino

Combination of multicomponent KA² and Pauson–Khand reactions: short synthesis of spirocyclic pyrrolocyclopentenones

• Riccardo Innocenti,
• Elena Lenci,
• Gloria Menchi and
• Andrea Trabocchi

Beilstein J. Org. Chem. 2020, 16, 200–211, doi:10.3762/bjoc.16.23

• in DOS [19][20][21][22], such as the exploitation of the Petasis three-component [23][24][25][26][27][28][29] and the Ugi four-component reactions [30][31][32][33], showing interesting properties for the generation of compounds characterized by high stereochemical and skeletal diversity. Although not

Emission solvatochromic, solid-state and aggregation-induced emissive α-pyrones and emission-tuneable 1H-pyridines by Michael addition–cyclocondensation sequences

• Natascha Breuer,
• Irina Gruber,
• Christoph Janiak and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2019, 15, 2684–2703, doi:10.3762/bjoc.15.262

• substituent in the 3-position [29]. Most syntheses generating 1H-pyridines make use of ethyl cyanoactate as a starting material. It can react with itself and forms a dimer by selfcondensation, catalyzed by transition metals [30][31]. Intrigued by the unusual pseudo-four-component AMAC synthesis we

• -pyrones from acid chlorides, terminal alkynes and dialkyl malonates. Consecutive pseudo-four-component alkynylation–Michael addition–cyclocondensation (AMAC) synthesis of 1H-pyridines 5a and an aniline derivative. Consecutive pseudo-four-component alkynylation–Michael addition–cyclocondensation (AMAC