Copper-promoted C5-selective bromination of 8-aminoquinoline amides with alkyl bromides

• Changdong Shao,
• Chen Ma,
• Li Li,
• Jingyi Liu,
• Yanan Shen,
• Chen Chen,
• Qionglin Yang,
• Tianyi Xu,
• Zhengsong Hu,
• Yuhe Kan and
• Tingting Zhang

Beilstein J. Org. Chem. 2024, 20, 155–161, doi:10.3762/bjoc.20.14

• brominated imides, such as N-bromosuccinimide (NBS), N-bromosaccharin (NBSA), tribromoisocyanuric acid (TBCA), 1,3-dibromo-5,5-dimethylhydantoin (DBDMH), and so on (Scheme 1, reaction 2) [21][22][23][24]. However, reports on the bromination of C5–H of 8-aminoquinolines employing acyl bromides, alkyl bromides

N-Boc-α-diazo glutarimide as efficient reagent for assembling N-heterocycle-glutarimide diads via Rh(II)-catalyzed N–H insertion reaction

• Grigory Kantin,
• Pavel Golubev,
• Alexander Sapegin,
• Alexander Bunev and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 1841–1848, doi:10.3762/bjoc.19.136

• α-bromo (α-oxysulfonyl) glutarimide (3, Scheme 1, route B). Although the first approach has readily available starting reagents, a simple synthesis process, and gives generally high yields, it is restricted in terms of the type of heterocycle that can be assembled (primarily cyclic imides and

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

• -aminosulfenylation with N-(aryl/alkylthio)imides 1 or 14 occurred in the presence of catalyst L. Meanwhile, Zhou and Chen′s research team was able to synthesize a broad range of enantioenriched naphthalenone structures 126 by utilizing another organocatalyst (Scheme 53) [85]. In the procedure, β‑naphthols 125

Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

• Austin Pounder,
• Eric Neufeld,
• Peter Myler and
• William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38

• norbornene derivatives 15 using imides 27 and tetraarylborates 28 (Scheme 5) [37]. The method utilizes C–N bond activation to trigger the reaction. The authors demonstrated a broad reaction scope. Electron-deficient amides were shown to perform worse than their electron-rich counterparts with the p

Dissecting Mechanochemistry III

• Lars Borchardt and
• José G. Hernández

Beilstein J. Org. Chem. 2022, 18, 1454–1456, doi:10.3762/bjoc.18.150

• Margetić used dibrominated polycyclic imides as substrates to generate reactive alkenes, which could be trapped in situ by several dienes through Diels−Alder cycloadditions by ball milling (Scheme 3) [7]. Further, Moores and co-workers synthesized phosphorus-bridged heptazine-based carbon nitrides (g-h-PCN

• . Mechanochemical palladium-catalyzed borylation protocol of aryl halides. 1,2-Debromination of polycyclic imides, followed by in situ trapping of the dienophile by several dienes. Synthesis of g-h-PCN from sodium phosphide and trichloroheptazine mediated by mechanochemistry. Mechanochemical intra- and

Synthetic strategies for the preparation of γ-phostams: 1,2-azaphospholidine 2-oxides and 1,2-azaphospholine 2-oxides

• Jiaxi Xu

Beilstein J. Org. Chem. 2022, 18, 889–915, doi:10.3762/bjoc.18.90

• -methylphenylphosphonamidate (36), and ethyl P-phenyl 2,6-dimethylphenylphosphinamide (37) did not undergo the reaction, showing a limited application of the synthetic strategy (Scheme 6) [26]. The products are carboxylic phosphonic imides. In 2021, Montchamp and co-workers synthesized 1,3-dihydrobenzo[d][1,2]azaphosphole 2

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

• Petar Strbac Davor Margetic Ruđer Bošković Institute, Bijenička cesta 54, HR-10002 Zagreb, Croatia 10.3762/bjoc.18.75 Abstract The solution phase 1,2-debromination of polycyclic imides using the Zn/Ag couple was successfully transferred to solid state mechanochemical conditions. The Zn/Ag couple

• polycyclic molecules given in Figure 1 are interesting reactive intermediates which could be applied in the Diels−Alder reactions of less reactive or thermally susceptible dienes. Often, these are generated in situ and trapped with dienes in a single pot, such as 7-oxanorbornadiene imides 1–3. For instance

• -reactions with solvent. An alternative method for the synthesis 7-oxanorbornadiene-2,3-anhydrides and imides is via retro Diels−Alder reaction employing the flash vacuum pyrolysis (FVP) technique [16]. However, the FVP also has disadvantages such as limited scope of functionalities which can withstand harsh

Mechanochemical halogenation of unsymmetrically substituted azobenzenes

• Dajana Barišić,
• Mario Pajić,
• Ivan Halasz,
• Darko Babić and
• Manda Ćurić

Beilstein J. Org. Chem. 2022, 18, 680–687, doi:10.3762/bjoc.18.69

• yield of 30% after one hour of milling (Table 1, entry 10 and Figures S77–S81 in Supporting Information File 1). Interestingly, in the reactions of L4 and L5 with NIS, instead of the halogenation of the aromatic C–H bond, imidation of the aliphatic C–H bond was observed. Imides are among the most

Recent advances in organocatalytic asymmetric aza-Michael reactions of amines and amides

• Pratibha Sharma,
• Raakhi Gupta and
• Raj K. Bansal

Beilstein J. Org. Chem. 2021, 17, 2585–2610, doi:10.3762/bjoc.17.173

• aromatic amines, amides, imides, etc. require the use of an appropriate catalyst to undergo a Michael addition with a suitable acceptor. In view of this, chemists endeavoured to develop different types of catalysts, particularly the chiral catalysts to accomplish asymmetric aza-MRs. The development of

Development of N-F fluorinating agents and their fluorinations: Historical perspective

• Teruo Umemoto,
• Yuhao Yang and
• Gerald B. Hammond

Beilstein J. Org. Chem. 2021, 17, 1752–1813, doi:10.3762/bjoc.17.123

• resulting from the reaction of the substrates with 1-5. 1-2. N-Fluoroperfluorosuccinimide and N-fluoroperfluoroglutarimide In 1981, Yagupols’kii and co-worker reported the synthesis of N-fluoroperfluorosuccinimide (2-1) and N-fluoroperfluoroglutarimide (2-2) by reaction of precursor imides with XeF2 (Scheme

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

• Guareschi imides, which, under the original protocol, is limited to ketones as the carbonyl component. When aldehydes are used, the adduct is aromatized to the corresponding 2-hydroxypyridone [50][51]. Finally, a modification of the type-IV Guareschi reaction that involves the condensation of two moles of

• and restless leg syndrome [53]. Guareschi imides exist in solution predominantly as dicarbonyl tautomers with a cis arrangement of the cyano groups. Conversely, the corresponding anions exist as a mixture of mono- and dienolized tautomers, with a strong preference (≈9:1) for the monoenolized form [8

• ]. Guareschi imides have been extensively investigated because of their bioactivity profile, the use as building blocks to access other classes of heterocycles as well as quaternary centres, and their remarkable chemistry [54]. By far, the most intriguing reaction of these is the so-called “1897 reaction

Bifurcated synthesis of methylene-lactone- and methylene-lactam-fused spirolactams via electrophilic amide allylation of γ-phenylthio-functionalized γ-lactams

• Tetsuya Sengoku,
• Koki Makino,
• Ayumi Iijima,
• Toshiyasu Inuzuka and
• Hidemi Yoda

Beilstein J. Org. Chem. 2020, 16, 2769–2775, doi:10.3762/bjoc.16.227

• methylene-lactams (C) through zinc-catalyzed addition to N-carbonyl imides [13][14][16]. Meanwhile, we also developed an umpolung electrophilic allylation of 3-heterosubstituted oxindole D for the synthesis of lactam analog of A (Scheme 1c) [17]. The oxindole D readily reacted with 2-(acetoxy)methyl

Synthesis of novel fluorinated building blocks via halofluorination and related reactions

• Attila Márió Remete,
• Tamás T. Novák,
• Melinda Nonn,
• Matti Haukka,
• Ferenc Fülöp and
• Loránd Kiss

Beilstein J. Org. Chem. 2020, 16, 2562–2575, doi:10.3762/bjoc.16.208

• cyclic olefins, such as diesters, imides, and lactams with varied functionalization patterns and different structural architectures is described. The synthetic methodologies were based on electrophilic activation through halonium ions of the ring olefin bonds, followed by nucleophilic fluorination with

• for the formation can be written only from the imides (rac)-11a,b. Apparently, the first step involves a base-catalyzed epimerization into a less-strained cis-annelated system, which undergoes ring inversion, enabling the large halogen atom to be equatorial. This is followed by a deprotonation next to

• phenylselenyl bromide was used alone (Scheme 21). The stereochemistry of the product (rac)-32 was determined using NOESY data. The tricyclic imides 19 and 24 failed to react with PhSeBr/Deoxo-Fluor®, and only unreacted starting compounds could be recovered from the reaction mixtures. Since these imides showed a

Recent synthesis of thietanes

• Jiaxi Xu

Beilstein J. Org. Chem. 2020, 16, 1357–1410, doi:10.3762/bjoc.16.116

• cleavage and aromatization to give substituted pyridines 255 [75] (Scheme 49). In 1989, Kanaoka and co-workers further studied the photo [2 + 2] cycloadditions of thiobarbiturates 256–258, whose skeletons consisted of a combination of a thioamide and an amide or a thioamide (two-imides system), and olefins

A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions

• Munmun Ghosh,
• Valmik S. Shinde and
• Magnus Rueping

Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264

• imides and no racemization was observed during the reaction (Scheme 50). In 2000, Pilli and co-workers published a vinylogous Mannich addition of silyloxyfuran to chiral N-acyliminium ions generated in situ from 157 which had been obtained from the anodic oxidation of 156 bearing a cyclohexyl-based

Synthesis of nonracemic hydroxyglutamic acids

• Dorota G. Piotrowska,
• Iwona E. Głowacka,
• Andrzej E. Wróblewski and
• Liwia Lubowiecka

Beilstein J. Org. Chem. 2019, 15, 236–255, doi:10.3762/bjoc.15.22

• derived from D- or L-tartaric acids can be used as starting materials in syntheses of enantiomers of 3,4-dihydroxyglutamic acids since they contain a vicinal diol fragment of the known stereochemistry. To demonstrate this strategy cyclic imides 106a (R = TBDMS) and 106b (R = Ac) readily prepared from L

• of (2S,3S,4R)-4 and (2R,3S,4R)-4 from cyclic imides 106. Reagents and conditions: a) NaBH4, MeOH; b) Ac2O, pyridine; c) Me3SiCN or Bu3SnCN, BF3·OEt2, toluene or CH2Cl2; d) Ce(NH4)2(NO3)6, MeCN/H2O; e) 6 M HCl, reflux, then Dowex 50W-X8. Synthesis of (2R,3R,4R)-4 and (2S,3R,4R)-4 from the cyclic meso

The mechanochemical synthesis of quinazolin-4(3H)-ones by controlling the reactivity of IBX

• Md Toufique Alam,
• Saikat Maiti and
• Prasenjit Mal

Beilstein J. Org. Chem. 2018, 14, 2396–2403, doi:10.3762/bjoc.14.216

• ]. Aryliodonium imides or iminoiodanes can be prepared by the treatment of electron-deficient amines with iodine(III). However, these compounds explode at higher temperatures [4] and hence are stored under inert atmosphere and low temperature [5]. Polyvalent iodine derivatives are versatile reagents for C–N bond

Recent advances in hypervalent iodine(III)-catalyzed functionalization of alkenes

• Xiang Li,
• Pinhong Chen and
• Guosheng Liu

Beilstein J. Org. Chem. 2018, 14, 1813–1825, doi:10.3762/bjoc.14.154

• bromines to alkenes, using ortho-substituted iodobenzene 62 as an organocatalyst (Scheme 19) [75]. A control experiment indicated that only trace amounts of products were observed in the absence of iodoarene catalyst (2%). A similar work involving a rearrangement of imides, which delivered α,α

Imide arylation with aryl(TMP)iodonium tosylates

• Souradeep Basu,
• Alexander H. Sandtorv and
• David R. Stuart

Beilstein J. Org. Chem. 2018, 14, 1034–1038, doi:10.3762/bjoc.14.90

• -deficient and sterically encumbered aryl groups. Keywords: arylation; C–N coupling; diaryliodonium; hypercoordinate iodine; metal-free; Introduction Imides are important structural units in a range of approved pharmaceuticals and agrochemicals (Scheme 1a) [1]. Despite the general prevalence of imides, N

• -aryl imide derivatives are relatively rare in such compounds. We were surprised by this disparity, but found that a lack of methods to synthesize N-aryl imides may explain their scarcity; this is particularly true relative to other N-aryl compounds. The survey of methods revealed that the dominant

• approach to N-aryl imides is to employ aniline starting materials (Scheme 1b, left), as was done in the synthesis of pentoxazone and related herbicides [2]. The alternative aromatic substitution approach with imide anions (Scheme 1b, right) is hampered by their low nucleophilicity [3]. Therefore

Cross-coupling of dissimilar ketone enolates via enolonium species to afford non-symmetrical 1,4-diketones

• Keshaba N. Parida,
• Gulab K. Pathe,
• Shimon Maksymenko and
• Alex M. Szpilman

Beilstein J. Org. Chem. 2018, 14, 992–997, doi:10.3762/bjoc.14.84

• involve the coupling of amide enolates with ketone enolates. Baran reported that stoichiometric Cu(2-ethylhexanoate)2 or Fe(acac)3 (2 equiv) are able to selectively oxidize imides, including Evan’s-type chiral imides, to the corresponding radicals. The formed radical then reacts selectively with a ketone

Diastereoselective Mannich reactions of pseudo-C₂-symmetric glutarimide with activated imines

• Tatsuya Ishikawa,
• Tomoko Kawasaki-Takasuka,
• Toshio Kubota and
• Takashi Yamazaki

Beilstein J. Org. Chem. 2017, 13, 2473–2477, doi:10.3762/bjoc.13.244

• unambiguously determined by X-ray crystallographic analysis (Figure 1) [16]. Based on this information a possible reaction mechanism was formulated as depicted in Scheme 1. It is well-known that oxazolidinone-derived imides in general construct bidentate chelation when they are converted to the corresponding

One-pot syntheses of blue-luminescent 4-aryl-1H-benzo[f]isoindole-1,3(2H)-diones by T3P^® activation of 3-arylpropiolic acids

• Melanie Denißen,
• Alexander Kraus,
• Guido J. Reiss and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2017, 13, 2340–2351, doi:10.3762/bjoc.13.231

• ][32] have indeed become a powerful tool in synthetic chemistry for convergently approaching substance libraries of luminescent molecules. In particular, blue-emissive heterocyclic chromophores, intensively requested in illumination research, are equally accessible by MCR strategies [33]. Cyclic imides

• are often prepared by condensation of acid anhydrides and amines [34]. Their applications are widespread, ranging from pharmaceutically active compounds [35] to agrochemicals [36] and fluorophores [37]. The characteristic photophysical properties of 1,8- and 2,3-naphthalene imides render the substance

• can be detected and monitored by absorption and emission spectroscopy. Furthermore, the investigation of a substance library of various 2,3- and 1,8-naphthalene imides has shown that the electronic nature of the ground and the excited state is decisively influenced by variation of the substitution

Mechanochemical N-alkylation of imides

• Anamarija Briš,
• Mateja Đud and
• Davor Margetić

Beilstein J. Org. Chem. 2017, 13, 1745–1752, doi:10.3762/bjoc.13.169

• . Reactions under solvent-free conditions in a ball mill gave good yields and could be put in place of the classical solution conditions. The method is general and can be applied to various imides and alkyl halides. Phthalimides prepared under ball milling conditions were used in a mechanochemical Gabriel

• synthesis of amines by their reaction with 1,2-diaminoethane. Keywords: ball milling; Gabriel reaction; imides; mechanochemistry; N-alkylation; Introduction The development of environmentally friendly organic reactions is a growing area of interest [1]. The reduction of the impact of chemical reactions on

• of imides with alkyl halogenides, and the results are presented in this paper. Until now, ball milling N-alkylations of ureas [15], hydrazones [16], imines [17][18], pyridines [19], pyrimidines [20], imidazoles [21], secondary amines [22], as well as allylic alkylation reactions [23] were reported in

1-Imidoalkylphosphonium salts with modulated C_α–P⁺ bond strength: synthesis and application as new active α-imidoalkylating agents

• Jakub Adamek,
• Roman Mazurkiewicz,
• Anna Węgrzyk and
• Karol Erfurt

Beilstein J. Org. Chem. 2017, 13, 1446–1455, doi:10.3762/bjoc.13.142

• . The crucial step in the method included the decarboxylative α-methoxylation of N-phthaloyl- or N-succinylamino acids to the corresponding N-(1-methoxyalkyl)imides, followed by the displacement of the methoxy group by the triarylphosphonium group through melting of the imide derivative with

• facilitates the cleavage of the highly polar Cα–P+ bond. Keywords: N-(1-arylalkyl)imides; α-imidoalkylating agents; imidoalkylation reactions; 1-imidoalkylphosphonium salts; Tscherniac–Einhorn-type reaction; Introduction The aminomethylation of C–H acidic compounds by the condensation of non-enolizable

• aromatic systems with strong electron-donating substituents (e.g., alkoxy-, polyalkoxy- and aminoarenes), or some activated heterocyclic systems such as indole [3][8][10][24][25]. The α-imidoalkylation reaction using N-(1-hydroxyalkyl)imides (almost entirely N-hydroxymethylphthalimide) in sulfuric acid

Brønsted acid-mediated cyclization–dehydrosulfonylation/reduction sequences: An easy access to pyrazinoisoquinolines and pyridopyrazines

• Ramana Sreenivasa Rao and
• Chinnasamy Ramaraj Ramanathan

Beilstein J. Org. Chem. 2017, 13, 428–440, doi:10.3762/bjoc.13.46

• preparation of piperazine-2,6-dione derivatives from N-benzenesulfonyliminodiacetic acid at room temperature. After careful reviewing of reagents for amide bond formation, the reagent CDI proved to be a very successful reagent for the preparation of imides, amides, esters and thioesters. Therefore, the

• obtained in 72% yield at room temperature in the presence of 10 mol % of DMAP. Similarly, this strategy has been extended to couple various arylethylamines with N-benzenesulfonyliminodiacetic acid at room temperature to furnish expected imides 7a–h in good yields (Scheme 2). The successful development of

• the potassium salt of N-benzyliminodiacetic acid in THF at reflux to furnish the expected imides 8a–c, 8h, and 8i in good yields (Scheme 6). The imide 8h was subjected to the cyclization reaction conditions using 6 equivalents of TfOH under neat conditions at 70 °C followed by reduction using NaBH4