A series of perylene diimide cathode interlayer materials for green solvent processing in conventional organic photovoltaics

• Kathryn M. Wolfe,
• Shahidul Alam,
• Eva German,
• Fahad N. Alduayji,
• Maryam Alqurashi,
• Frédéric Laquai and
• Gregory C. Welch

Beilstein J. Org. Chem. 2023, 19, 1620–1629, doi:10.3762/bjoc.19.119

• (KSC), Physical Sciences and Engineering Division (PSE), Material Science and Engineering Program (MSE), Thuwal 23955-6900, Saudi Arabia 10.3762/bjoc.19.119 Abstract Herein, we report on the design, synthesis, physical and chemical properties, and organic photovoltaic (OPV) device performance of four

• ]. However, while progress has been made by increases in PCEs from ≈10% to ≈19% in the last decade, many of the materials used in OPVs suffer from low thermal and/or photostability, lengthy syntheses, high cost, and require harmful reagents for synthesis and processing. Therefore, it is necessary to design

• film, but use of such alcohol-based solvents limits the types of organic materials to be used as CILs. With ethyl acetate as a processing solvent a wider range of organic materials can be developed and studied as CILs. Herein, we report on the design, synthesis, and application of four new CILs using

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

• related 2-azabicyclo[4.4.1]undecane system, albeit in lower yield. Keywords: alkaloids; azabicycles; Heck reaction; iron complex; tropone; Introduction Azapolycycles are embedded within numerous biologically active alkaloids [1] and pharmaceuticals [2]. As such, novel approaches to the synthesis of

• these motifs have attracted considerable interest. The synthesis of azapolycycles containing a seven-membered carbocyclic ring is particularly challenging in contrast to comparable skeletons containing only five- or six-membered rings [3]. Thus, comparatively few general methods exist for accessing

• our successful efforts to access this bridged bicyclic ring system. Results and Discussion As shown in Scheme 2a, the synthesis of the requisite Heck reaction precursor began with the addition of the known allylic amine 5 to tricarbonyl(tropone)iron, immediately followed by Boc-protection of the crude

Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• past century, new knowledge on radical chemistry has both promoted and been generated from the emergence of polymer synthesis and modification techniques. In this review, we discuss radical chemistry in polymer science from four interconnected aspects. We begin with radical polymerization, the most

• employed technique for industrial production of polymeric materials, and other polymer synthesis involving a radical process. Post-polymerization modification, including polymer crosslinking and polymer surface modification, is the key process that introduces functionality and practicality to polymeric

• late last century. To continue with the discussion on polymer construction, section 2 explores some emergent polymer synthesis techniques via a radical process but other than a chain-growth mechanism by addition of radical species to vinyl monomers. In section 3, we cover radical chemistry approaches

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

• its combination with organometallic chemistry for site-selective C−H bond functionalization [3][4]. Recent years have witnessed many viable strategies for the synthesis of complex targets utilizing photoredox catalysis, electroorganic catalysis, Lewis acid catalysis, and transition-metal-free

Lewis acid-promoted direct synthesis of isoxazole derivatives

• Dengxu Qiu,
• Chenhui Jiang,
• Pan Gao and
• Yu Yuan

Beilstein J. Org. Chem. 2023, 19, 1562–1567, doi:10.3762/bjoc.19.113

• nitrite as a nitrogen-oxygen source, and solely using aluminum trichloride as the additive. This approach circumvents the need for costly or highly toxic transition metals and presents a novel pathway for the synthesis of isoxazole derivatives. Keywords: aluminum trichloride; Lewis acid; isoxazole

• derivatives; sodium nitrite; transition metals; Introduction The isoxazole derivatives not only exist in many natural products [1][2][3] and pharmaceutical intermediates [4][5][6][7], but also have great application values in organic synthesis [8][9] (Figure 1). In the past decades, many methods have been

• reported [16]. In 2015, Yang’s group [10][17] reported the copper-catalyzed conversion of methylarenes into isoxazole derivatives with KNO3 as the source of nitrile oxide (Scheme 1, reaction 1). In 2019, Deng’s group [18] developed a three-component synthesis method of isoxazole derivatives using TBN as

Secondary metabolites of Diaporthe cameroonensis, isolated from the Cameroonian medicinal plant Trema guineensis

• Bel Youssouf G. Mountessou,
• Élodie Gisèle M. Anoumedem,
• Blondelle M. Kemkuignou,
• Yasmina Marin-Felix,
• Frank Surup,
• Marc Stadler and
• Simeon F. Kouam

Beilstein J. Org. Chem. 2023, 19, 1555–1561, doi:10.3762/bjoc.19.112

• have been reported [32]. The importance of dibenzo-α-pyrones is manifold as they can also be used as key intermediates in the synthesis of therapeutic compounds [32]. Since compound 1 was isolated as a racemic mixture, while compound 2 is a diacetylated derivative of the mycotoxin alternariol known for

Morpholine-mediated defluorinative cycloaddition of gem-difluoroalkenes and organic azides

• Tzu-Yu Huang,
• Mario Djugovski,
• Sweta Adhikari,
• Destinee L. Manning and
• Sudeshna Roy

Beilstein J. Org. Chem. 2023, 19, 1545–1554, doi:10.3762/bjoc.19.111

• plausible pathways. Attractive elements include the regioselective and straightforward direct synthesis of fully substituted 1,2,3-triazoles, which are otherwise difficult to access, from readily available starting materials. Keywords: [3 + 2] cycloaddition; defluorination; fully decorated 1,2,3-triazoles

• ][12], inflammation [13], bacterial [14][15], and viral infections [16]. Hence, new ways to rapidly and efficiently access 1,2,3-triazole heterocyclic motifs are still in demand. However, methods for the direct synthesis of 1,4,5-trisubstituted-1,2,3-triazoles are limited [17]. This is highly desirable

• are typically accessed in two ways: (1) direct synthesis using metal or metal-free catalysis and (2) post-functionalization of disubstituted-1,2,3-triazoles [17][18]. The direct synthesis of fully substituted triazoles entails either metal-free carbonyl-based [19][20][21] or metal-mediated and strain

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

• scaffolds is the introduction of a benzylidene moiety on C5 via a Knoevenagel reaction. Here, a facile synthesis of 5-arylidenerhodanines via a Knoevenagel reaction in an ʟ-proline-based deep eutectic solvent (DES) is reported. This method is fast (1 h at 60 °C), easy, catalyst-free and sustainable as no

• -competitive PI3Kγ inhibitors [7]. A few years ago, we worked intensively on 2-heteroarylimino-1,3-thiazolidin-4-ones as potential antitumor agents [8] and we demonstrated that derivative F was an interesting CDC25A inhibitor [9]. Up to now, the synthesis of most organic compounds still uses harmful reagents

• promising emerging class of green solvents as they offer numerous advantages, such as low volatility, non-flammability, chemical and thermal stability, recyclability, and above all a good biodegradability [10]. Moreover, their synthesis is usually easy and cheap as DES are formed by simply mixing an H-bond

Complexes of resorcin[4]arene with secondary amines: synthesis, solvent influence on “in-out” structure, and theoretical calculations of non-covalent interactions

• Waldemar Iwanek

Beilstein J. Org. Chem. 2023, 19, 1525–1536, doi:10.3762/bjoc.19.109

• , these compounds are capable of forming complexes with small organic molecules. The current paper focuses on the synthesis of complexes between R[4]A and secondary aliphatic amines (sec-amines). Through NMR spectroscopy, it was observed that “in-out” complexes are formed depending on the solvent. It was

• unsubstituted R[4]A, the current work shows that these molecules are capable of forming complexes with small organic molecules using their cavity. The synthesis of R[4]A complexes with secondary aliphatic amines is presented where the stoichiometry of the complexes was found to depend on the size of the bound

• groups’ protons not involved in the formation of hydrogen bonds in the R[4]A molecule was calculated with the CREST program using the “pKa” command. General method for the synthesis of R[4]A complexes with sec-amines: 0.2 g (0.225 mmol) of R[4]A was weighed into a round-bottomed flask and dissolved in 20

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

• derivatives, compound B8 represents the natural compound pseudopalmatine [39]. The synthesis of this compound has been reported, albeit through alternative methods [33][38][40]. Reports indicated that unlike most other plant-derived protoberberines, pseudopalmatine has had far less pharmacological

• synthesis began with the generation of substituted 2-bromo-1-aminonaphthalenes 9 and 10 (Scheme 6). After α-bromination of tetralones 1 and 2, intermediates 3 and 4 underwent elimination/aromatization with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) to afford 2-bromo-1-naphthols 5 and 6 in fairly good yield

• complete decomposition. With the desired naphthylamines in hand, we were able to complete our synthesis of four chelerythrine variants as shown in Scheme 7. After N-formylation providing intermediates 11 and 12 in good yield, a three-step sequence was performed: Suzuki coupling of the aryl bromide with one

Unraveling the role of prenyl side-chain interactions in stabilizing the secondary carbocation in the biosynthesis of variexenol B

• Moe Nakano,
• Rintaro Gemma and
• Hajime Sato

Beilstein J. Org. Chem. 2023, 19, 1503–1510, doi:10.3762/bjoc.19.107

• biosynthesis of trichobrasilenol [22], by combined methods of computational and experimental chemistry. Recently, Dickschat et al. reported the synthesis of a novel diterpene compound, variexenol B, using a substrate analogue called iso-GGPP (Scheme 1) [23]. This biosynthetic pathway has two interesting

N-Sulfenylsuccinimide/phthalimide: an alternative sulfenylating reagent in organic transformations

• Fatemeh Doraghi,
• Seyedeh Pegah Aledavoud,
• Mehdi Ghanbarlou,
• Bagher Larijani and
• Mohammad Mahdavi

Beilstein J. Org. Chem. 2023, 19, 1471–1502, doi:10.3762/bjoc.19.106

• organosulfur chemistry, sulfenylating agents are an important key in C–S bond formation strategies. Among various organosulfur precursors, N-sulfenylsuccinimide/phthalimide derivatives have shown highly electrophilic reactivity for the asymmetric synthesis of many organic compounds. Hence, in this review

• synthesis, medicinal chemistry, and materials science [1][2][3][4][5]. For example, they are used in the treatment of cancer [6][7][8], inflammation [9][10][11], human immunodeficiency virus [12][13], Alzheimer’s and Parkinson’s diseases [14][15]. Scheme 1 shows selected examples of sulfur-containing

• field of organic synthesis. These compounds are readily accessible, safe, and more stable than toxic, unstable, and foul-smelling thiols. These electrophilic sulfur sources have deserved particular interest for the C–S bond formation via the reaction with various nucleophiles. Their preparation is

Cyclization of 1-aryl-4,4,4-trichlorobut-2-en-1-ones into 3-trichloromethylindan-1-ones in triflic acid

• Vladislav A. Sokolov,
• Andrei A. Golushko,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2023, 19, 1460–1470, doi:10.3762/bjoc.19.105

• ; indanones; trichloromethyl group; triflic acid; Introduction Superelectrophilic activation of organic compounds under the action of strong Brønsted and Lewis acids is an effective method for the synthesis of various carbocycles and heterocycles, and polyfunctional compounds (see books [1][2] and reviews [3

• calculations, and to study their intramolecular cyclization in triflic acid into the synthetically and medicinally relevant (see recent reviews [12][13][14][15][16][17][18]) indan-1-ones. Results and Discussion The synthesis of 1-aryl-4,4,4-trichloro-3-hydroxybutan-1-ones (CCl3-hydroxy ketones) 1a–o was

• , exact structures of compounds 1g,h,s,t,v were confirmed by X-ray analysis (see Supporting Information File 1). The hydroxy ketones 1 were used as precursors for the synthesis of 1-aryl-4,4,4-trichlorobut-2-en-1-ones (CCl3-enones) 2 by dehydration of compounds 1 with p-toluenesulfonic acid monohydrate at

Functions of enzyme domains in 2-methylisoborneol biosynthesis and enzymatic synthesis of non-natural analogs

• Binbin Gu,
• Lin-Fu Liang and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1452–1459, doi:10.3762/bjoc.19.104

• ; isotopes; substrate analogs; terpenes; Introduction The musty odorant 2-methylisoborneol (1, Scheme 1) has first been obtained through synthesis from camphor [1] and has subsequently been discovered as a natural product in streptomycetes [2][3]. The volatile compound was later also found in various other

• products that have been identified by GC–MS analysis and the synthesis of reference compounds [30][31]. Notably, 2MIBS also shows some substrate flexibility and can convert GPP into monoterpenes in vitro, albeit with less efficiency as compared to the conversion of 2-Me-GPP [24]. On the other hand, single

• of the individually expressed domains shows a similarly rapid precipitation as domain B alone. However, some interaction between the individually expressed domains A and B can be concluded from their reduced productivity in comparison to domain B alone. Enzymatic synthesis of non-natural analogs of 2

α-(Aminomethyl)acrylates as acceptors in radical–polar crossover 1,4-additions of dialkylzincs: insights into enolate formation and trapping

• Angel Palillero-Cisneros,
• Paola G. Gordillo-Guerra,
• Fernando García-Alvarez,
• Olivier Jackowski,
• Franck Ferreira,
• Fabrice Chemla,
• Joel L. Terán and
• Alejandro Perez-Luna

Beilstein J. Org. Chem. 2023, 19, 1443–1451, doi:10.3762/bjoc.19.103

• was poorly efficient with tosylamine, leading to product 7 in low 20% yield [25]. With the aim to develop asymmetric variants, we also considered the synthesis of N-(tert-butanesulfinyl) α-(aminomethyl)acrylates 8a–c. For this purpose, the application of the same protocol with (±)-tert

• . Importantly, the protocol was found to be similarly applicable with enoates 8b (Table 3, entry 6) and 8c (entry 7) having tert-butyl and benzyl ester groups, which, as the methyl ester unit, are typical in the context of amino acid synthesis. ZnBu2 was also amenable to 1,4-addition (Table 3, entry 8), but not

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• the simplicity of their synthesis and the modularity of their stereoelectronic properties, NHCs have unquestionably emerged as one of the most fascinating and well-known species in chemical science. The remarkable stability of NHCs can be attributed to both kinetic as well as thermodynamic effects

• diversity, low cost, and versatile applications. This article overviews applications of NHC–Cu(I) complexes as catalysts in organic synthesis over the last 12 years, which include hydrosilylation reactions, conjugate addition, [3 + 2] cycloaddition, A3 reaction, boration and hydroboration, N–H and C(sp2)–H

• ligands in organometallic chemistry. After the first synthesis of stable monomeric NHCs, spectroscopic studies promptly revealed their similarity with phosphines. Indeed, both these classes of ligands are σ-donor ligands with low π-backdonating character [16][17]. In the beginning, the NHCs were perceived

One-pot nucleophilic substitution–double click reactions of biazides leading to functionalized bis(1,2,3-triazole) derivatives

• Hans-Ulrich Reissig and
• Fei Yu

Beilstein J. Org. Chem. 2023, 19, 1399–1407, doi:10.3762/bjoc.19.101

• conditions found were studied with a second model reaction in order to examine its suitability for the synthesis of potential carbohydrate mimetic precursors (Scheme 3). Sodium azide, benzyl bromide (5) and enantiopure bicyclic 1,2-oxazin-4-one derivative 6 [53] which bears a propargylic ether moiety as

• aminopyran and aminooxepane derivatives and goal of this study employing alkyne component G and biazides in situ-generated from H. Synthesis of model compound 3 under conventional conditions and as a one-pot process employing benzyl bromide (5), alkyne 2 and sodium azide as precursors for the click reaction

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

• electrophilic trapping of the intermediary indole anion with alkyl halides provides a concise one-pot synthesis of 3-iodoindoles. The latter are valuable substrates for Suzuki arylations, which are exemplified with the syntheses of four derivatives, some of them are blue emitters in solution and in the solid

• [9][10][11] and their preparation is an evergreen in organic synthesis [12][13][14][15]. Although the classical Fischer indole synthesis provides a very reliable and broadly applicable access to indole derivatives [16][17][18], striving for new indole syntheses is ongoing. In particular, metal

• -catalyzed processes for accessing indoles have become attractive alternatives over the past decades [19][20][21][22][23][24]. Besides Larock's indole synthesis employing alkyne anellation [25] and Cacchi's cyclization of ortho-alkynylanilines [20][22] catalytic syntheses of indoles from alkynes have become

Visible-light-induced nickel-catalyzed α-hydroxytrifluoroethylation of alkyl carboxylic acids: Access to trifluoromethyl alkyl acyloins

• Feng Chen,
• Xiu-Hua Xu,
• Zeng-Hao Chen,
• Yue Chen and
• Feng-Ling Qing

Beilstein J. Org. Chem. 2023, 19, 1372–1378, doi:10.3762/bjoc.19.98

• ; Introduction Acyloins (also known as α-hydroxy ketones) are widely found as structural motif in natural products [1][2][3][4][5][6][7] and bioactive molecules [8][9][10][11] (Figure 1). They can also be used as building blocks in organic synthesis [12][13][14], involved in numerous transformations to other

• experiments showed that trifluoromethyl acyloins can selectively induce apoptosis in human oral cancer cells [22][23] and have therefore attracted much more attention. However, trifluoromethyl acyloins were not widely used due to the challenge associated with their synthesis. Certain progress has been made in

• the synthesis of trifluoromethyl aromatic acyloins. Maekawa’s group [24] developed a tandem reaction of the reductive coupling between arylaldehydes and ethyl trifluoroacetate in the presence of magnesium and chlorotrimethylsilane, followed by desilylation to produce the trifluoromethyl aromatic

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

• naturally occurring ether lipids. In 1979 the discovery of the structure of the platelet-activating factor (PAF) that belongs to the alkyl ether class of lipids increased the interest in these bioactive lipids and further promoted the synthesis of non-natural ether lipids that was initiated in the late 60’s

• naturally occurring ether lipids (e.g., PAF) or synthetic derivatives that were developed to study their biological properties. The synthesis of neutral or charged ether lipids are reported with the aim to assemble in this review the most frequently used methodologies to prepare this specific class of

• the scientific community for different reasons: 1) to have an overview on the methods already available, 2) to invite scientists that are working on synthesis methodology to apply their works to the design of ELs analogues, 3) the methods reported in this review can be useful tools for the scientific

Organic thermally activated delayed fluorescence material with strained benzoguanidine donor

• Alexander C. Brannan,
• Elvie F. P. Beaumont,
• Nguyen Le Phuoc,
• George F. S. Whitehead,
• Mikko Linnolahti and
• Alexander S. Romanov

Beilstein J. Org. Chem. 2023, 19, 1289–1298, doi:10.3762/bjoc.19.95

• containing a rigid benzoguanidine ligand in its molecular structure. Results and Discussion Synthesis and structure 4BGIPN was prepared in 70% yield by aromatic nucleophilic substitution reaction from 2,4,5,6-tetrafluoroisophthalonitrile and 5H-benzo[d]benzo[4,5]imidazo[1,2-a]imidazole (benzoguanidine) after

• Laboratory at the University of Manchester. Mass spectrometry data were obtained by the Mass Spectrometry Laboratory at the University of Manchester. Synthesis of 4BGIPN. 5H-Benzo[d]benzo[4,5]imidazo[1,2-a]imidazole (benzoguanidine, [10]) (700 mg, 3.38 mmol) was added to a suspension of NaH (81.0 mg, 3.38

Non-noble metal-catalyzed cross-dehydrogenation coupling (CDC) involving ether α-C(sp³)–H to construct C–C bonds

• Hui Yu and
• Feng Xu

Beilstein J. Org. Chem. 2023, 19, 1259–1288, doi:10.3762/bjoc.19.94

• synthetic strategy for the construction of C–C bonds in organic synthesis (Scheme 1b). Compared with traditional coupling reactions, the CDC strategy has the following advantages: 1) atom economy, 2) green and efficient reaction, 3) a wide range of substrate sources. Therefore, organic chemists consider the

• drugs are shown in Scheme 1c: Empagliflozin to treat type-2 diabetes [34][35][36], tegafur is used in medicine to treat a variety of cancers [37][38], lubazodone is an experimental antidepressant [39][40], and sofosbuvir is used to treat hepatitis C virus (HCV) infections [41][42]. For the synthesis of

• synthesis of compounds with quaternary centers and natural products with high structural complexity. In 2014, Li et al. reported a CuCl2-catalyzed cross-dehydrogenation coupling reaction of C(sp3)–H bonds adjacent to an ether oxygen and the C(sp3)–H bonds at the α-position of a carbonyl functionality in the

Metal catalyst-free N-allylation/alkylation of imidazole and benzimidazole with Morita–Baylis–Hillman (MBH) alcohols and acetates

• Olfa Mhasni,
• Jalloul Bouajila and
• Farhat Rezgui

Beilstein J. Org. Chem. 2023, 19, 1251–1258, doi:10.3762/bjoc.19.93

• Michael acceptor unit. They have found application as valuable synthons and useful precursors for the synthesis of various biologically active molecules [1][2][3]. Recently, MBH adducts, as electrophilic substrates, have been employed to achieve fruitful results in allylic substitution reactions with

• various nucleophiles, including C- and heteronucleophiles, such as compounds bearing –OH, –SH, and –NH groups [4][5][6][7]. Among them, the carbon–nitrogen bond formation through N-nucleophilic substitution reactions plays a central role for the synthesis of numerous compounds exhibiting various

• , Yang et al. [18][19] have developed a catalytic system involving Pd/Ti(OiPr)4 or Pd/carboxylic acid for the direct allylation of anilines with alcohols. The synthesis of N-allylimidazole derivatives 3 has been previously carried out using acyclic MBH adducts bearing good leaving groups, such as bromide

Acetaldehyde in the Enders triple cascade reaction via acetaldehyde dimethyl acetal

• Alessandro Brusa,
• Debora Iapadre,
• Maria Edith Casacchia,
• Alessio Carioscia,
• Giuliana Giorgianni,
• Giandomenico Magagnano,
• Fabio Pesciaioli and
• Armando Carlone

Beilstein J. Org. Chem. 2023, 19, 1243–1250, doi:10.3762/bjoc.19.92

• organic synthesis to build complex scaffolds starting from simple starting materials. The Enders three-component cascade reaction was a cornerstone in the field and a plethora of organocatalyzed cascade reactions followed. However, acetaldehyde was not shown as a successful reaction partner, probably

• reason, the use of MCRs is appealing in the construction of natural or synthetic products [2][3][4][5] or libraries of compounds [2], and is generally considered an advantage in organic synthesis for atom economy, waste reduction and time saving. Cascade reactions are defined as chemical processes in

• which two or more bond-forming steps happen under identical reaction conditions, and where a subsequent transformation takes place at the functionality obtained in the former bond-forming event. Cascade reactions are valuable tools for streamlining the synthesis of structurally complex molecules in a

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

• ), in which the in situ-generated adduct of thiophenol and 3-phenacylideneoxindole was believed to be the key intermediate [53][54][55]. Inspired by these elegant synthetic protocols and in continuation of our aim to develop convenient reactions for the synthesis of diverse spiro compounds [56][57][58

• . This reaction provided efficient synthetic protocols for the synthesis of dispiro[indoline-3,2'-quinoline-3',3''-indoline] and dispiro[indoline-3,2'-pyrrole-3',3''-indoline] derivatives. A plausible reaction mechanism was proposed to explain the selective formation of the different polycyclic compounds