Formaldehyde surrogates in multicomponent reactions

• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Bernhard Westermann

Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45

• developed in which the alkene compound has been replaced with other surrogates for electrophilic addition, such as ketones [32][33][34]. In the case of the carbonyl component, it is generally an aromatic aldehyde [30][33][34] and there are not many reports on using formaldehyde in the Povarov reaction. In a

• consequently, different catalytic strategies to afford the electrophilic addition on the final cyclization step. Finally, other examples show the synthesis of 3-aryl and alkyl quinoline-3-carboxylate derivatives under acid catalysis for the activation of DMSO via the Pummerer reaction (Scheme 10). In these

• %), but when DMSO is used as solvent and reagent, the yield was greatly improved. The proposed mechanism involves the activation of the disulfide component by CuBr2 as the Lewis acid (Scheme 14). The copper(II) center coordinates the sulfur atom of the disulfide allowing for the electrophilic addition to

N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240

• -O-trimethylsilyl-ʟ-rhamnopyranose (4b) with TMSI gave intermediate A containing an anomeric iodide. Electrophilic addition of rhamnosyl iodide A to one of the two imino groups of 13 gave intermediate B. Another electrophilic addition of n-propyl mercaptane to the second imino group afforded

Phenylseleno trifluoromethoxylation of alkenes

• Clément Delobel,
• Armen Panossian,
• Gilles Hanquet,
• Frédéric R. Leroux,
• Fabien Toulgoat and
• Thierry Billard

Beilstein J. Org. Chem. 2024, 20, 2434–2441, doi:10.3762/bjoc.20.207

• developed an electrophilic phenylseleno trifluoromethoxylation of alkenes, which leads to β-selenylated trifluoromethoxylated compounds or, upon subsequent reduction, to the trifluoromethoxylated ones. Keywords: DNTFB; electrophilic addition; fluorine; selenium; trifluoromethoxy; Introduction Due to the

• compounds from alkenes and DDPyOCF3, more precisely to α-trifluoromethoxylated, β-phenylselenylated compounds. Results and Discussion The electrophilic addition of phenylselenyl halides to alkenes to form a selenonium intermediate that can be intercepted by an external nucleophile is a well-known method to

Synthesis of 4-functionalized pyrazoles via oxidative thio- or selenocyanation mediated by PhICl₂ and NH₄SCN/KSeCN

• Jialiang Wu,
• Haofeng Shi,
• Xuemin Li,
• Jiaxin He,
• Chen Zhang,
• Fengxia Sun and
• Yunfei Du

Beilstein J. Org. Chem. 2024, 20, 1453–1461, doi:10.3762/bjoc.20.128

• selenium center of intermediate B resulted in the formation of two molecules of Cl–SeCN. Subsequently, Cl–SeCN undergoes an electrophilic addition reaction with pyrazole 1 to give intermediate C, which, after deprotonative rearomatization affords the 4-selenocyanated pyrazole 3. Conclusion In conclusion

Competing electrophilic substitution and oxidative polymerization of arylamines with selenium dioxide

• Vishnu Selladurai and
• Selvakumar Karuthapandi

Beilstein J. Org. Chem. 2024, 20, 1221–1235, doi:10.3762/bjoc.20.105

• been used in oxyselenenylation of olefins, which follows an electrophilic addition mechanism [23][24][25]. However, such reagents are rarely used for electrophilic substitution of aromatic systems. Recently, notable progress has been made in the use of aromatic electrophilic substitution to synthesize

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

• reaction mixture for up to 8 cycles before signs of deactivation were observed. The mechanism of action was also identical with the Cu–isatin Schiff base complex activation of the carbonyl group, facilitating the electrophilic addition of indole (Scheme 19). The main drawback of the method, however, is the

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• depicted in Scheme 14, the 12-membered ring orifice of fullerene 51 was first enlarged by electrophilic addition of sulfur. After encapsulation of H2 molecule(s) (n = 1 or 2), four synthetic steps were required to reduce the hole size and ultimately obtain cage-closed compound (H2)n@54. In order to remove

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

• sulfur atom to Fe3+ to generate Fe2+ and radical cation I. Subsequent cleavage of the N–S bond led to cation II and radical III. Interaction of III with Fe2+ regenerated the Fe3+ species and IV. At the same time, electrophilic addition of II to alkene 9 yielded intermediate V, which was subjected to the

• -catalyzed C–H sulfenylation at the C2-position of protected and unprotected indoles 105 to form 2-thioindoles 106 (Scheme 44) [78]. The reaction initiated with TFA-promoted electrophilic addition of 1 to 105 towards C3-sulfenylated indole I, which was protonated by TFA, led to intermediate II. Then

• method, diverse β-alkoxy sulfides were synthesized without the need to any catalyst, or additive. The reaction proceeded through the formation of carbonium ion intermediate I, which underwent electrophilic addition of alcohol to provide product 152. In the meantime, N-(arylthio)succinimide 1 as a

Exploring the role of halogen bonding in iodonium ylides: insights into unexpected reactivity and reaction control

• Carlee A. Montgomery and
• Graham K. Murphy

Beilstein J. Org. Chem. 2023, 19, 1171–1190, doi:10.3762/bjoc.19.86

• , they believed that the reaction was likely initiated by either single electron transfer between the reagents (not shown), or by electrophilic addition of the olefin onto the ylide, forming intermediate adduct 17. This was followed by formation of iodocycle 18, from which reductive elimination of

• ). In the earlier study, Koser recovered 24 and 27, and they proposed an ionic mechanism wherein the ylide acted as a nucleophile, giving 26 as the initial intermediate (Figure 7, top). To account for the differing products observed, Hadjiarapoglou instead suggested that an electrophilic addition

Aromatic C–H bond functionalization through organocatalyzed asymmetric intermolecular aza-Friedel–Crafts reaction: a recent update

• Anup Biswas

Beilstein J. Org. Chem. 2023, 19, 956–981, doi:10.3762/bjoc.19.72

• N-aryl-substituted anilines 59 which decreased in case of N-alkyl-substituted anilines. This observation led to the development of a plausible transition state of the stereoselective electrophilic addition which included dual H-bonding interactions between both the substrates and the catalyst along

Bromination of endo-7-norbornene derivatives revisited: failure of a computational NMR method in elucidating the configuration of an organic structure

• Demet Demirci Gültekin,
• Arif Daştan,
• Yavuz Taşkesenligil,
• Cavit Kazaz,
• Yunus Zorlu and
• Metin Balci

Beilstein J. Org. Chem. 2023, 19, 764–770, doi:10.3762/bjoc.19.56

• for those ‘revised structures’ [3]. This paper impelled us to revisit our original work and assess the validity of Novitskiy and Kutateladze’s claim whether our assignment was indeed wrong. Results and Discussion In 2008 we investigated the electrophilic addition of bromine to 1 (7-endo-bicyclo[2.2.1

Recent advances in the tandem annulation of 1,3-enynes to functionalized pyridine and pyrrole derivatives

• Yi Liu,
• Puying Luo,
• Yang Fu,
• Tianxin Hao,
• Xuan Liu,
• Qiuping Ding and
• Yiyuan Peng

Beilstein J. Org. Chem. 2021, 17, 2462–2476, doi:10.3762/bjoc.17.163

• be carried out at 90 °C in 8 h to provide the 5-sulfenyl-substituted nicotinates 19 efficiently. Based on previous literature and control experiments, the possible mechanism is outlined in Scheme 8. First, the Cu-complex-polarized X−X bond can promote the electrophilic addition onto the alkyne to

Synthesis of 5-arylacetylenyl-1,2,4-oxadiazoles and their transformations under superelectrophilic activation conditions

• Andrey I. Puzanov,
• Dmitry S. Ryabukhin,
• Anna S. Zalivatskaya,
• Dmitriy N. Zakusilo,
• Darya S. Mikson,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2021, 17, 2417–2424, doi:10.3762/bjoc.17.158

• ). Conclusion For the first time reported, we have synthesized 5-arylacetylene derivatives of 1,2,4-oxadiazoles, i.e., 5-(2-arylethynyl)-3-aryl-1,2,4-oxadiazoles. In the Brønsted superacid TfOH, these oxadiazoles react in a way of electrophilic addition to the acetylene bond. They give products of

Advances in mercury(II)-salt-mediated cyclization reactions of unsaturated bonds

• Sumana Mandal,
• Raju D. Chaudhari and
• Goutam Biswas

Beilstein J. Org. Chem. 2021, 17, 2348–2376, doi:10.3762/bjoc.17.153

• electrophilic addition (Scheme 26). Schwartz et al. developed a new route for the synthesis of exocyclic enol ether 83 and endocyclic enol ether 85 involving a Hg(II)-induced cyclization of acetylenic alcohols 82 and 84, respectively [79]. This work revealed that the regioselectivity of the Hg(II) addition to

Breaking paracyclophane: the unexpected formation of non-symmetric disubstituted nitro[2.2]metaparacyclophanes

• Suraj Patel,
• Tyson N. Dais,
• Paul G. Plieger and
• Gareth J. Rowlands

Beilstein J. Org. Chem. 2021, 17, 1518–1526, doi:10.3762/bjoc.17.109

• pathway involves electrophilic addition para to the phenol to form the ipso-substituted nitro 12 compound. Subsequent rearrangement of the nitro species 12 to the nitrito dienone 13, by homolysis and recombination of the radical pair, is followed by hydrolysis to furnish alcohol 6 [70]. Addition of the

• rearrangement to [2.2]metaparacyclophane (3) occurred prior to nitration. Firstly, no [2.2]metaparacyclophane (3) was ever observed in our nitration reaction mixtures. Secondly, Cram has reported that the major product of both bromination and acylation of [2.2]metaparacyclophane (3) arises from electrophilic

• addition to the para-substituted ring [36]. Substitution at the 4-position of the meta-ring is only the minor product. We attempted to confirm this hypothesis by preparing [2.2]metaparacyclophane (3) by the triflic acid-mediated rearrangement of [2.2]paracyclophane (1) but were unable to isolate a pure

Pentannulation of N-heterocycles by a tandem gold-catalyzed [3,3]-rearrangement/Nazarov reaction of propargyl ester derivatives: a computational study on the crucial role of the nitrogen atom

• Giovanna Zanella,
• Martina Petrović,
• Dina Scarpi,
• Ernesto G. Occhiato and
• Enrique Gómez-Bengoa

Beilstein J. Org. Chem. 2020, 16, 3059–3068, doi:10.3762/bjoc.16.255

• acid, as previously reported [45]. In the next step, the electrophilic addition of iodine monochloride to the double bond of the enesulfonamide 10, followed by a nucleophilic attack of methanol on the formed iodonium ion afforded the α-methoxy-β-iodopiperidine 11 as a single stereoisomer (91% yield

Reactions of 3-aryl-1-(trifluoromethyl)prop-2-yn-1-iminium salts with 1,3-dienes and styrenes

• Thomas Schneider,
• Michael Keim,
• Bianca Seitz and
• Gerhard Maas

Beilstein J. Org. Chem. 2020, 16, 2064–2072, doi:10.3762/bjoc.16.173

• reaction sequence [46]. Taking into account the presumably high electrophilic character of the 1-(trifluoromethyl)propyn-1-iminium ion, for its reaction with styrenes we could not exclude a priori an initial electrophilic addition at the olefinic bond (with formation of a benzyl cation intermediate). The

Et₃N/DMSO-supported one-pot synthesis of highly fluorescent β-carboline-linked benzothiophenones via sulfur insertion and estimation of the photophysical properties

• Dharmender Singh,
• Vipin Kumar and
• Virender Singh

Beilstein J. Org. Chem. 2020, 16, 1740–1753, doi:10.3762/bjoc.16.146

• -nitrochalcone 1bA and elemental sulfur by testing different activators (Table 1). Recent findings revealed that a combination of an aliphatic amine with DMSO activated elemental sulfur for an electrophilic addition to generate thioaurones and benzothiophenes [59]. At 70 °C, the use of DIPEA in combination with

• 2-nitrobenzaldehyde (C) could not be achieved with KOH in MeOH or Cs2CO3 in DMSO. To probe the reaction mechanism, a control experiment was conducted with model substrate 1bA in the presence of a radical scavenger (TEMPO) to check the possibility of a radical mechanism vs an electrophilic addition

Synthesis of 3-substituted isoxazolidin-4-ols using hydroboration–oxidation reactions of 4,5-unsubstituted 2,3-dihydroisoxazoles

• Lívia Dikošová,
• Júlia Laceková,
• Ondrej Záborský and
• Róbert Fischer

Beilstein J. Org. Chem. 2020, 16, 1313–1319, doi:10.3762/bjoc.16.112

• -unsubstituted 2,3-dihydroisoxazoles in moderate to very good yields, starting from readily available 5-acetoxy- and 5-hydroxyisoxazolidines [7][8]. Their reactivity in electrophilic addition reactions allows for a straightforward introduction of a hydroxy group at the C-4 position of the resulting

Synthesis and anticancer activity of bis(2-arylimidazo[1,2-a]pyridin-3-yl) selenides and diselenides: the copper-catalyzed tandem C–H selenation of 2-arylimidazo[1,2-a]pyridine with selenium

• Mio Matsumura,
• Tsutomu Takahashi,
• Hikari Yamauchi,
• Shunsuke Sakuma,
• Yukako Hayashi,
• Tadashi Hyodo,
• Tohru Obata,
• Kentaro Yamaguchi,
• Yasuyuki Fujiwara and
• Shuji Yasuike

Beilstein J. Org. Chem. 2020, 16, 1075–1083, doi:10.3762/bjoc.16.94

• -position to form the intermediate C and the selenide anion F. The intermediate C undergoes a reductive elimination and aromatization to give the selenide 3 and Cu(I). Moreover, the Cu-mediated electrophilic addition of 3 and selenium affords G, which aromatizes to form E and then probably undergoes a

[1,3]/[1,4]-Sulfur atom migration in β-hydroxyalkylphosphine sulfides

• Katarzyna Włodarczyk,
• Piotr Borowski and
• Marek Stankevič

Beilstein J. Org. Chem. 2020, 16, 88–105, doi:10.3762/bjoc.16.11

• OH group, facilitated proton transfer from the γ- to β-carbon atom via a process similar to the elimination/electrophilic addition to alkenes pathway. The computational results discussed above showed that the crucial point for sulfur atom migration was the formation of a tertiary carbocation at the β

Hypervalent iodine compounds for anti-Markovnikov-type iodo-oxyimidation of vinylarenes

• Igor B. Krylov,
• Stanislav A. Paveliev,
• Mikhail A. Syroeshkin,
• Alexander A. Korlyukov,
• Pavel V. Dorovatovskii,
• Yan V. Zubavichus,
• Gennady I. Nikishin and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2018, 14, 2146–2155, doi:10.3762/bjoc.14.188

• electrophilic addition of iodine. The use of allylbenzene in the reaction did not result in the formation of the desired iodo-oxyimide, presumably due to a side process of oxidation of the allylic methylene fragment. The use of N-hydroxyphthalimide (2a) gives iodo-oxymidation products with yields generally

• target products (yields up to 91%). In contrast to previous studies in which oxidants promote the electrophilic addition of iodine to the C=C bond, radical addition predominates in the discovered process. Radical pathway starts from the attack of imide-N-oxyl radicals on the double C=C bond, which allows

Enantioselective dioxytosylation of styrenes using lactate-based chiral hypervalent iodine(III)

• Morifumi Fujita,
• Koki Miura and
• Takashi Sugimura

Beilstein J. Org. Chem. 2018, 14, 659–663, doi:10.3762/bjoc.14.53

• derivative was employed for the asymmetric dioxytosylation of styrene and its derivatives. The electrophilic addition of the hypervalent iodine(III) compound toward styrene proceeded with high enantioface selectivity to give 1-aryl-1,2-di(tosyloxy)ethane with an enantiomeric excess of 70–96% of the (S

• styrene with 4a–e preferentially gave (S)-3, which forms via an electrophilic addition of the iodane toward the Si face of styrene, followed by an SN2 reaction with the tosylate ion. If an SN1 mechanism were involved in the oxytosylation of I1, the enantiomeric ratio of 3 would decrease owing to the

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF₃SO₂Na

• Hélène Guyon,
• Hélène Chachignon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

Electrophilic trifluoromethylselenolation of terminal alkynes with Se-(trifluoromethyl) 4-methylbenzenesulfonoselenoate

• Clément Ghiazza,
• Anis Tlili and
• Thierry Billard

Beilstein J. Org. Chem. 2017, 13, 2626–2630, doi:10.3762/bjoc.13.260

• ][56][57][58][59][60][61][62][63][64][65][66][67] and CF3SeTs [68]. Results and Discussion Recently, we have described the electrophilic addition of CF3SeCl to alkenes to access α-chloro-β-trifluoromethylselenolated molecules [65]. These products are particularly interesting because the presence of the

• reaction was stirred at 25 °C for 15–18 hours (conversion was checked by 19F NMR with PhOCF3 as internal standard). The crude residue was purified by chromatography to afford the desired products 3–5. Single-crystal X-ray structure of 3a. Electrophilic addition of 1a to alkynes. Yields shown are those of