Efficacy of radical reactions of isocyanides with heteroatom radicals in organic synthesis

• Akiya Ogawa and
• Yuki Yamamoto

Beilstein J. Org. Chem. 2024, 20, 2114–2128, doi:10.3762/bjoc.20.182

• which a wide-range of 2-phosphoryl-substituted quinoxalines 26 were prepared in one pot via reaction of ortho-diisocyanoarenes with diarylphosphine oxides in the presence of AgNO3 (Scheme 18b) [65]. Chalcogen compounds such as PhSH and (PhSe)2 can be used as chalcogeno radical sources for the

From perfluoroalkyl aryl sulfoxides to ortho thioethers

• Yang Li,
• Guillaume Dagousset,
• Emmanuel Magnier and
• Bruce Pégot

Beilstein J. Org. Chem. 2024, 20, 2108–2113, doi:10.3762/bjoc.20.181

• strategy to improve or modulate their physicochemical and biological properties [41][42][43][44][45], only few publications have reported a [3,3]-rearrangement with fluorinated molecules (Scheme 1c). In 2020, Wang and co-workers have developed a one-pot [3,3]-sigmatropic rearrangement/Haller–Bauer reaction

• Yang Li Guillaume Dagousset Emmanuel Magnier Bruce Pegot Université Paris-Saclay, UVSQ, CNRS, UMR 8180, Institut Lavoisier de Versailles, 78035 Versailles Cedex, France 10.3762/bjoc.20.181 Abstract Access to original ortho thioether derivatives was achieved through a [3,3]-rearrangement in a one

• -pot two-step protocol. Several aryl-SCF3 compounds are reported by variation of the nitrile or of the trifluoroalkyl sulfoxide starting material. The variation of the perfluoroalkyl chain was also possible. Keywords: ortho functionalization; rearrangement; sulfoxide; Introduction Since decades

Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps

• Ignaz Betcke,
• Alissa C. Götzinger,
• Maryna M. Kornet and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178

• were overcome by the addition–cyclocondensation of α,β-unsaturated ketones. Embedding 1,3-dipolar cycloadditions into a one-pot process has additionally been developed for concise syntheses of pyrazoles. The MCR strategy also allows for concatenating classical condensation-based methodology with modern

• ; one-pot reactions; pyrazole; Introduction Pyrazoles and 1,2-diazoles [1] have received considerable interest in the past years. Although they are rarely found in nature [2], their spectrum of biological activity is remarkably broad, leading to numerous applications in pharmaceutical chemistry [3][4

• concatenation of organic elementary steps in a one-pot fashion. Many reviews on general syntheses of pyrazoles have been published [25][26][27][28][29][30][31][32][33][34][35][36][37][38], as well as a few dedicated reviews on MCR synthesis of pyrazole derivatives [39][40][41]. In sensu stricto, multicomponent

Diastereoselective synthesis of highly substituted cyclohexanones and tetrahydrochromene-4-ones via conjugate addition of curcumins to arylidenemalonates

• Deepa Nair,
• Abhishek Tiwari,
• Banamali Laha and
• Irishi N. N. Namboothiri

Beilstein J. Org. Chem. 2024, 20, 2016–2023, doi:10.3762/bjoc.20.177

• , curcumin showcases its Michael donor–acceptor ability in different ways, such as simple Michael addition, [4 + 2] annulation, Michael addition followed by cyclization or one-pot multicomponent reactions (MCR), etc. (Scheme 1) [25]. In 2011, our group reported the reactivity of curcumin as a Michael donor

• cascade triple-Michael (Michael/Michael/oxa-Michael) reaction between curcumins and isatylidene malononitriles, giving spiro-oxindoles in excellent yields and diastereoselectivities [36]. Sahu et al. introduced a one-pot multicomponent reaction of curcumin, arylaldehyde and 2-aminobenzothiazole to

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

• Cristina Martini,
• Muhammad Idham Darussalam Mardjan and
• Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

• , obtaining an enzyme-metal biohybrid catalyst [22]. The authors tested it in a one-pot GBB reaction–Suzuki coupling, employing 5-bromo-2-aminopyridine (20), benzaldehyde (2), tert-butyl isocyanide (5) and phenylboronic acid (21). Compound 22 was obtained in 87% yield by performing the GBB reaction at room

• their reduced nucleophilicity. Also the synthesis of a bis-imidazo[1,2-a]pyridine scaffold was achieved in 43% yield from the pseudo-para-substituted bis-aldehyde, using the same conditions, but longer reactions times (6 days). Following the same approach, the authors also developed a one-pot protocol

• (IPT)-mediated intramolecular oxidative annulation and a hydroxylamine-induced ring cleavage of intermediate 48. With this one-pot sequential procedure they synthesized 49 in yields up to 95% (Scheme 19). The subsequent GBB-3CR led to the unique 1H-imidazo[1,2-a]imidazole core 50 with 4 distinct

A facile three-component route to powerful 5-aryldeazaalloxazine photocatalysts

• Ivana Weisheitelová,
• Radek Cibulka,
• Marek Sikorski and
• Tetiana Pavlovska

Beilstein J. Org. Chem. 2024, 20, 1831–1838, doi:10.3762/bjoc.20.161

• have been successfully synthesised through a one-pot, three-component reaction involving N,N-dimethylbarbituric acid, an aromatic aldehyde and aniline. By utilizing readily available reagents, this approach opens up the opportunity for the efficient formation of a variety of 5-aryldeazaalloxazines

• purification. Thus, it significantly improves existing approaches. Keywords: catalysis; deazaalloxazine; flavin; multicomponent approach; one-pot reaction; Introduction Heterocyclic compounds containing pyrimidine and quinoline motifs in their structure, both of natural and synthetic origin, find a wide set

• continuation of our work on the synthesis of powerful photoredox flavins [14][15][16][17][18][19], we developed an efficient, general, one-pot domino method for the synthesis of a series of novel 5-aryldeazaalloxazines 2 from readily available substrates via a three-component fashion (Figure 1C). Results and

Oxidative fluorination with Selectfluor: A convenient procedure for preparing hypervalent iodine(V) fluorides

• Samuel M. G. Dearman,
• Xiang Li,
• Yang Li,
• Kuldip Singh and
• Alison M. Stuart

Beilstein J. Org. Chem. 2024, 20, 1785–1793, doi:10.3762/bjoc.20.157

• (I) precursor 18 in 73% isolated yield in a one-pot procedure using 5.5 equivalents of Selectfluor (see Supporting Information File 1). Unfortunately, we were never able to replicate Amey and Martin’s fluorination of phenylmagnesium bromide using bis(trifluoromethyl)trifluoroiodane 22 (Scheme 6). The

Ugi bisamides based on pyrrolyl-β-chlorovinylaldehyde and their unusual transformations

• Alexander V. Tsygankov,
• Vladyslav O. Vereshchak,
• Tetiana O. Savluk,
• Serhiy M. Desenko,
• Valeriia V. Ananieva,
• Oleksandr V. Buravov,
• Yana I. Sakhno,
• Svitlana V. Shishkina and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2024, 20, 1773–1784, doi:10.3762/bjoc.20.156

• University, Svobody sq., 4, 61022, Kharkiv, Ukraine 10.3762/bjoc.20.156 Abstract By one-pot four- and three-component Ugi reactions involving convertible isocyanides and unexplored pyrrole-containing β-chlorovinylaldehyde, a small library of 20 bisamides with unusual behavior in post-Ugi transformations was

• of the bisamides 6–8. Moreover, traces of the ketobisamides 12 were also observed when the synthesis was carried out in 96% EtOH. The one-pot synthesis allows to combine two consecutive steps, the Ugi-4CR and the post-Ugi reaction, by keeping the mixture of starting materials 1, 2c, 3 and 4d at 25 °C

• Ugi bisamide 5d in the presence of HCl. Conditions: (A) 5 equiv HCl, MeOH, 80 °C, 3 h; (B) 5 equiv HCl, EtOH, MW 120 °C, 15 min; (C) 5 equiv HCl, MeCN, MW 100 °C, 20 min. The Ugi-4CR with the participation of p-anisidine and benzyl isocyanide. Successful attempt at tandem one-pot coupling of the Ugi

Harnessing unprotected deactivated amines and arylglyoxals in the Ugi reaction for the synthesis of fused complex nitrogen heterocycles

• Javier Gómez-Ayuso,
• Pablo Pertejo,
• Tomás Hermosilla,
• Israel Carreira-Barral,
• Roberto Quesada and
• María García-Valverde

Beilstein J. Org. Chem. 2024, 20, 1758–1766, doi:10.3762/bjoc.20.154

• considering the diastereoselectivity observed when enantiopure (S)-α-methylbenzylamine was used as chiral component in the two-step syntheses from amine surrogates [22], we assayed our new strategy to achieve a one-pot diastereoselective synthesis of benzodiazepinones 6 (Scheme 2, Table 2). Interestingly, the

• dipyrrolopiperazinone 12 quantitatively. In view of the interest of these structures and the poor global yield obtained because of the purification in the first step, we tried the synthesis of these polycyclic systems in a one-pot sequence. In this way, after performing the Ugi reaction for 24 h, the reaction mixture

• (right). The thermal ellipsoid plot (Olex2) is at the 40% probability level. X-ray diffraction structure of dipyrrolopiperazinone 12c. The thermal ellipsoid plot (Olex2) is at the 40 % probability level. Synthesis of benzodiazepinones 5 from anthranilic acid derivatives. Diastereoselective one-pot

Syntheses and medicinal chemistry of spiro heterocyclic steroids

• Laura L. Romero-Hernández,
• Ana Isabel Ahuja-Casarín,
• Penélope Merino-Montiel,
• Sara Montiel-Smith,
• José Luis Vega-Báez and
• Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

• preparing spiro α-methylene-β-lactones from different steroidal propargylic alcohols [13]. The procedure involves a one-pot Pd-catalyzed cyclocarbonylation of alkynols using 5 mol % of Pd(CH3CN)2Cl2 as a catalyst precursor and 30 mol % of 2-(dibutyl)phosphine-1-(2,6-diisopropylphenyl)-1H-imidazole as

• as a 1:1 mixture of diastereomers (Scheme 4). The same procedure was also applied to estrone to insert the spiro moiety at C-17 in 70% yield [14]. Spiro-β-lactam steroids A novel one-pot procedure to build spiro-β-lactams from enamides was described by Liu et al. The research group had previously

• -2H-furan-3-one framework at position C-17 [22]. The one-pot procedure involved the condensation of diethyl oxalate with the α-hydroxy ketone moiety of derivatives 28, immediately followed by a cyclization between the 17α-hydroxy group and the carbonyl group of the α-ketoester in 29. Spiro compounds

Chemo-enzymatic total synthesis: current approaches toward the integration of chemical and enzymatic transformations

• Ryo Tanifuji and
• Hiroki Oguri

Beilstein J. Org. Chem. 2024, 20, 1693–1712, doi:10.3762/bjoc.20.151

• and subsequent oxidation yielded aldehyde 18, a precursor for the intramolecular ring closure of the eight-membered ring. Upon treatment of 18 with BF3·Et2O, diastereoselective Prins cyclization of 18 proceeded to generate secondary alcohol 19. Subsequent one-pot treatment with (n-Bu)4NF·HF resulted

• to the biosynthetic conversion of 9 into 11 (Scheme 2B), an α-hydroxylated ketone 25 with suitable protections of the C3 and C8 hydroxy groups was synthesized from 23 in one pot. Conversion of the secondary alcohol in 25 into triflate 26 enabled the alkenyl shift from C1 to C12 followed by

• JuvEV, homologous enzymes to TylGIV and TylGV (Scheme 8) [68]. Reconstruction of the JuvEIV–JuvEV-catalyzed cascade enzymatic conversions successfully furnished 4 in one pot from chemically synthesized thioester 77 mimicking biosynthetic intermediate 64. For the chemical synthesis of mimic 77, the left

Ring opening of photogenerated azetidinols as a strategy for the synthesis of aminodioxolanes

• Henning Maag,
• Daniel J. Lemcke and
• Johannes M. Wahl

Beilstein J. Org. Chem. 2024, 20, 1671–1676, doi:10.3762/bjoc.20.148

• promising starting point for pursuing this ring-opening attempt [41]. We hypothesized that this approach would allow the synthesis of 3-amino-1,2-diols, a motif commonly found in pharmaceuticals such as, e.g., β-blockers [42]. Our envisioned one-pot protocol features protonation of the azetidine from

Photoswitchable glycoligands targeting Pseudomonas aeruginosa LecA

• Yu Fan,
• Ahmed El Rhaz,
• Stéphane Maisonneuve,
• Emilie Gillon,
• Maha Fatthalla,
• Franck Le Bideau,
• Guillaume Laurent,
• Samir Messaoudi,
• Anne Imberty and
• Juan Xie

Beilstein J. Org. Chem. 2024, 20, 1486–1496, doi:10.3762/bjoc.20.132

• commercially available p,p’-dihydroxyazobenzene (6), by using our recently developed DMC (2-chloro-1,3-dimethylimidazolinium chloride)-mediated one-pot glycosylation method in water [28], followed by O-alkylation of the remaining hydroxy group with BrCH2CH2NHBoc and acidic deprotection (Scheme 1). Three

Synthesis of 2-benzyl N-substituted anilines via imine condensation–isoaromatization of (E)-2-arylidene-3-cyclohexenones and primary amines

• Lu Li,
• Na Li,
• Xiao-Tian Mo,
• Ming-Wei Yuan,
• Lin Jiang and
• Ming-Long Yuan

Beilstein J. Org. Chem. 2024, 20, 1468–1475, doi:10.3762/bjoc.20.130

• further demonstrated. As depicted in Scheme 5, we first attempted scale-up synthesis of product 4aa. Pleasingly, when starting from 2a on a 6.0 mmol scale, the product 4aa was afforded in 74% yield. We also conducted the successive synthesis of 4aa in a manner of one-pot procedure. On the condition of

• delivered synchronously. Substrate scope of primary amines 3. Conditions: reactions conducted with 2 (0.2 mmol) and 3b–y (2.0 mmol) were stirred in DME (2 mL) at 60 °C; isolated yields. Gram-scale reaction and successive one-pot synthesis. Synthetic manipulation. Optimization studies.a Supporting

Synthesis of cyclic β-1,6-oligosaccharides from glucosamine monomers by electrochemical polyglycosylation

• Md Azadur Rahman,
• Hirofumi Endo,
• Takashi Yamamoto,
• Shoma Okushiba,
• Norihiko Sasaki and
• Toshiki Nokami

Beilstein J. Org. Chem. 2024, 20, 1421–1427, doi:10.3762/bjoc.20.124

• intramolecular glycosylation (Scheme 1a) [14]. One-pot two-step synthesis via electrochemical polyglycosylation and intramolecular glycosylation has also been achieved in order to synthesize unnatural cyclic oligosaccharides of glucosamine (Scheme 1b) [15]. Here, we report the direct synthesis of cyclic

Synthesis of substituted triazole–pyrazole hybrids using triazenylpyrazole precursors

• Simone Gräßle,
• Laura Holzhauer,
• Nicolai Wippert,
• Olaf Fuhr,
• Martin Nieger,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2024, 20, 1396–1404, doi:10.3762/bjoc.20.121

• the triazole unit via a copper-catalyzed azide–alkyne cycloaddition. The developed methodology was used to synthesize a library of over fifty new multi-substituted pyrazole–triazole hybrids. We also demonstrate a one-pot strategy that renders the isolation of potentially hazardous azides obsolete. In

• followed by the addition of diisopropylamine, either in a one-pot synthesis or in two consecutive steps (Table 1). Subsequently, different aliphatic and aromatic substituents were attached to the pyrazole nitrogen by nucleophilic substitution with suitable organohalides 16 and cesium carbonate [3]. Due to

• via copper-catalyzed cross-coupling [29] with an electron-rich aryl substituent was exemplarily conducted to further expand the scope of possible products (see Scheme S2, Supporting Information File 1). We also investigated the scope and limitations of a one-pot reaction for the triazene cleavage and

Synthetic applications of the Cannizzaro reaction

• Bhaskar Chatterjee,
• Dhananjoy Mondal and
• Smritilekha Bera

Beilstein J. Org. Chem. 2024, 20, 1376–1395, doi:10.3762/bjoc.20.120

• enantioselectivity of the resultant product (Scheme 1). A one-pot oxidation–Cannizzaro reaction of aryl methyl ketones to mandelic acid derivatives was observed in the presences of ytterbium triflate as the catalyst. The intramolecular reaction sequence employed a SeO2/Yb(OTf)3 combination to affect the in-situ

Generation of alkyl and acyl radicals by visible-light photoredox catalysis: direct activation of C–O bonds in organic transformations

• Mithu Roy,
• Bitan Sardar,
• Itu Mallick and
• Dipankar Srimani

Beilstein J. Org. Chem. 2024, 20, 1348–1375, doi:10.3762/bjoc.20.119

• (Scheme 16). This one-pot strategy involved the reaction of xanthates formed in situ with electron-deficient alkenes under visible-light photoredox conditions in the presence of PPh3. This approach did not require multistep synthesis of starting materials. In addition, alcohol groups in polyols could be

Rhodium-catalyzed homo-coupling reaction of aryl Grignard reagents and its application for the synthesis of an integrin inhibitor

• Kazuyuki Sato,
• Satoki Teranishi,
• Atsushi Sakaue,
• Yukiko Karuo,
• Atsushi Tarui,
• Kentaro Kawai,
• Hiroyuki Takeda,
• Tatsuo Kinashi and
• Masaaki Omote

Beilstein J. Org. Chem. 2024, 20, 1341–1347, doi:10.3762/bjoc.20.118

• 10.3762/bjoc.20.118 Abstract A novel Rh-catalyzed one-pot homo-coupling reaction of aryl Grignard reagents was achieved. The reaction with bromobenzenes having an electron-donating group or a halogen substituent gave the corresponding homo-coupling products in good yields, although the reaction using

• preparation of the Grignard reagent followed by the homo-coupling reaction. Various conditions were examined and biphenyl (3b) was obtained in 85% yield in a one-pot reaction, when bromobenzene (5b) was treated with 1.5 equiv of Mg (turnings, grade for Grignard reaction) under reflux conditions of THF for 24

• h in the presence of RhCl(PPh3)3 (Scheme 4). Next, we investigated the Rh-catalyzed one-pot Ullmann-type reaction conditions by using various substrates, and the results are summarized in Figure 1. In the reaction with bromobenzenes bearing an electron-donating group such as bromotoluene and

Diameter-selective extraction of single-walled carbon nanotubes by interlocking with Cu-tethered square nanobrackets

• Guoqing Cheng and
• Naoki Komatsu

Beilstein J. Org. Chem. 2024, 20, 1298–1307, doi:10.3762/bjoc.20.113

• can calculate larger system (>500 atoms) containing transition metals more precisely [16][17]. Result and Discussion Synthesis of Cu-tethered square nanobrackets 1b A pyrene-based nanobracket 4b was synthesized via a one-pot Suzuki coupling followed by the formation of dipyrrin from the dialdehyde 3

Synthesis and physical properties of tunable aryl alkyl ionic liquids based on 1-aryl-4,5-dimethylimidazolium cations

• Stefan Fritsch and
• Thomas Strassner

Beilstein J. Org. Chem. 2024, 20, 1278–1285, doi:10.3762/bjoc.20.110

• formation of N-oxides, which were then reduced using iron powder. The imidazoles were synthesized in a one-pot procedure on a scale of up to 400 mmol. Quaternization of the imidazoles using bromoalkanes with different chain lengths provided the bromide salts 10–36. Conversion to the NTf2 ionic liquids 37–63

Domino reactions of chromones with activated carbonyl compounds

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 1256–1269, doi:10.3762/bjoc.20.108

• triethylamine in methanol afforded benzocoumarines 18a–ac (Scheme 4) [33][34]. The formation of the product, which was obtained in a two-step one-pot reaction, can be explained by a mechanism similar to the one discussed for the formation of 17. 1,4-Addition gave intermediate D which was isolated, but used in

• of DBU afforded furo[3,2-b]chromen-9-one 36a in 32% yield. Based on this observation, the two-step one-pot reaction of ketoamides 34a–f with 3-halochromones 15a–c was studied which afforded furo[3,2-b]chromen-9-ones 36a–f, albeit, in only low to moderate yields (Scheme 19) [41]. The formation of

• . Similarly to products 35, relatively low yields were observed for reactions of methoxy-substituted 3-halochromones. The two-step one-pot reaction of N-unsubstituted ketoamide 33a with 3-halochromones 29a and 31a afforded spirocycles 36a,b, albeit, in only moderate yields (Scheme 20) [41]. The formation of

The Ugi4CR as effective tool to access promising anticancer isatin-based α-acetamide carboxamide oxindole hybrids

• Carolina S. Marques,
• Aday González-Bakker and
• José M. Padrón

Beilstein J. Org. Chem. 2024, 20, 1213–1220, doi:10.3762/bjoc.20.104

• , 38200, La Laguna, Spain 10.3762/bjoc.20.104 Abstract Considering early-stage drug discovery programs, the Ugi four-component reaction is a valuable, flexible, and pivotal tool, facilitating the creation of two new amide bonds in a one-pot fashion to effectively yield the desired α-aminoacylamides. Here

• aspects. Multicomponent reactions (MCRs) are remarkable tools which demonstrated great potential for more sustainable production of active pharmaceutical ingredients (API’s). These flexible and versatile one-pot transformations in which three or more reagents are combined to access a new complex scaffold

Introduction of peripheral nitrogen atoms to cyclo-meta-phenylenes

• Koki Ikemoto and
• Hiroyuki Isobe

Beilstein J. Org. Chem. 2024, 20, 1207–1212, doi:10.3762/bjoc.20.103

• achieved with one-pot Suzuki–Miyaura coupling to arrange phenylene rings and pyridinylene rings in an alternating fashion. Analyses with UV–vis spectroscopy showed changes in the photophysical properties with nitrogen doping, and X-ray crystallographic analyses experimentally revealed the presence of

• -doped [n]CMPs, 3a and 3b, were synthesized via one-pot Suzuki–Miyaura coupling [12] (Scheme 1). Previously, we synthesized [n]CMPs with inward-focused nitrogen dopants by using Suzuki–Miyaura coupling with Pd(PPh3)4 as the catalyst [13] and applied this method to outward-radiated congeners in this work

Manganese-catalyzed C–C and C–N bond formation with alcohols via borrowing hydrogen or hydrogen auto-transfer

• Mohd Farhan Ansari,
• Atul Kumar Maurya,
• Abhishek Kumar and
• Saravanakumar Elangovan

Beilstein J. Org. Chem. 2024, 20, 1111–1166, doi:10.3762/bjoc.20.98

• regeneration of complex Mn7-a (Scheme 14). In 2020, Morrill's group reported the one-pot synthesis of N-methylarylamines from nitroarenes using methanol as a methylating agent and reductant [44]. When substituted nitroarenes were methylated with methanol under optimal conditions (5 mol % Mn3, 2 equiv of KOH at

• ) as a base in toluene at 140 °C for 36 h that gave up to 84% yield (Scheme 29A). More interestingly, double alkylation also occurred in one pot using acetophenone and 4-methoxyacetophenone with different benzyl alcohols under the optimized conditions. In the first step, monoalkylation of the methyl