An accelerated Rauhut–Currier dimerization enabled the synthesis of (±)-incarvilleatone and anticancer studies

• Tharun K. Kotammagari,
• Sweta Misra,
• Sayantan Paul,
• Sunita Kunte,
• Rajesh G. Gonnade,
• Manas K. Santra and
• Asish K. Bhattacharya

Beilstein J. Org. Chem. 2023, 19, 204–211, doi:10.3762/bjoc.19.19

• reported in the literature is described. The reaction was discovered by Rauhut and Currier [5] in the year 1963. It is a nucleophile-catalyzed C–C bond-forming reaction between two Michael acceptors. This reaction provides access to diverse classes of densely functionalized molecules. Rauhut–Currier (RC

• intermolecular fashion to form a C–C bond between the two Michael acceptors. This whole process involves two intermolecular conjugate additions, which leads to low reactivity. In case of intramolecular RC reactions, a high reactivity is observed. This is due to one intermolecular and one intramolecular conjugate

Identification and determination of the absolute configuration of amorph-4-en-10β-ol, a cadinol-type sesquiterpene from the scent glands of the African reed frog Hyperolius cinnamomeoventris

• Angelique Ladwig,
• Markus Kroll and
• Stefan Schulz

Beilstein J. Org. Chem. 2023, 19, 167–175, doi:10.3762/bjoc.19.16

• slow reaction, but a 37% solution of formaldehyde in water/methanol proved to be successful (Table 1, entries 5–10). Nevertheless, two problems were encountered. First, the Diels–Alder products 9–11 proved to be also active Mannich acceptors, leading to the unwanted unsaturated ketone 20, a double

Combining the best of both worlds: radical-based divergent total synthesis

• Kyriaki Gennaiou,
• Antonios Kelesidis,
• Maria Kourgiantaki and
• Alexandros L. Zografos

Beilstein J. Org. Chem. 2023, 19, 1–26, doi:10.3762/bjoc.19.1

• drastically the radical stability, nucleophilicity, and selectivity of 139 [73]. Furnishing of the common scaffold 130 can be carried out via an attack of intermediates of this type (e.g., 139) on Michael acceptors. Tosyl group deprotection of 130, followed by selenium anhydride oxidation and catalytic

Redox-active molecules as organocatalysts for selective oxidative transformations – an unperceived organocatalysis field

• Elena R. Lopat’eva,
• Igor B. Krylov,
• Dmitry A. Lapshin and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2022, 18, 1672–1695, doi:10.3762/bjoc.18.179

• [74][76][80][86][87][88]. To facilitate the anodic oxidation of N-hydroxyphthalimide, basic pyridine derivatives are used as the N-hydroxyphthalimide proton acceptors [87]. In many cases electrolysis can be performed in the galvanostatic mode in a simple undivided cell, which is convenient for

• which are stable to self-decay are used in oxidative organocatalysis as hydrogen atom acceptors or one-electron oxidants (Scheme 17). The stability of cation radical to self-decay is achieved in bicyclic structures where the cleavage of a hydrogen atom from the carbon atom next to nitrogen is

Electroreductive coupling of 2-acylbenzoates with α,β-unsaturated carbonyl compounds: density functional theory study on product selectivity

• Naoki Kise and
• Toshihiko Sakurai

Beilstein J. Org. Chem. 2022, 18, 956–962, doi:10.3762/bjoc.18.95

• by cyclic voltammetry (Table 3) and acceptors 2 revealed no reduction peaks from 0 to −2.00 V vs SCE [5][6]. Therefore, this electroreductive coupling is initiated by the reduction of compounds 1. There are two possible reaction mechanisms for the reductive coupling of 1 with 2a as illustrated in

Introducing a new 7-ring fused diindenone-dithieno[3,2-b:2',3'-d]thiophene unit as a promising component for organic semiconductor materials

• Valentin H. K. Fell,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Eman J. Hussien and
• Peter J. Skabara

Beilstein J. Org. Chem. 2022, 18, 944–955, doi:10.3762/bjoc.18.94

• evaporation, average mobilities of 14.20 ± 2.55 cm2 V−1 s−1, with a maximum value of 17.2 cm2 V−1 s−1 were achieved. In recent years, fused thiophene molecules also achieved outstanding performances in OPVs. This was especially driven by recent developments in non-fullerene acceptors (NFA) [29]. One prominent

Post-synthesis from Lewis acid–base interaction: an alternative way to generate light and harvest triplet excitons

• Hengjia Liu and
• Guohua Xie

Beilstein J. Org. Chem. 2022, 18, 825–836, doi:10.3762/bjoc.18.83

• acceptors Some Lewis acids have good solubility in common organic solvents, which makes it easy to fabricate films for optoelectronic applications [24]. Because of their strong electrophilicity [25], Lewis acids may dominate charge distributions of the fluorescent materials featured with electron-rich

• acids B(C6F5)3 and B(C6H5)3 as electron acceptors, respectively [29]. B(C6F5)3 displays high chemical stability and Lewis acidity [30]. Moreover, its good solubility endows the possibility to form Lewis acid–base adducts in films by solution processing. The strong electron attraction of the fluorine

• temperature. Figure 12 was reprinted from [29], Chemical Engineering Journal, vol. 380, by M. Zhang; G. Xie; Q. Xue; H. Wang, “Electroluminescence of intra-molecular exciplexes based on novel Lewis acid borane acceptors and a high triplet level donor”, article no. 122527, Copyright (2020), with permission

Identification of the new prenyltransferase Ubi-297 from marine bacteria and elucidation of its substrate specificity

• Jamshid Amiri Moghaddam,
• Huijuan Guo,
• Karsten Willing,
• Thomas Wichard and
• Christine Beemelmanns

Beilstein J. Org. Chem. 2022, 18, 722–731, doi:10.3762/bjoc.18.72

• -2-naphthoic acid (DHNA) via an intermediate decarboxylative coupling step yielding demethylmenaquinone (DMK) [9]. In contrast, COX10 and chlorophyll synthases are known to fuse prenyl or phytyl tails to porphyrins as acceptors, while homogentisate prenyltransferases catalyze the condensation of

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

• tetraphenylethene (TPE) units which act as an aggregation-induced emissive (AIE) fluorophore [65]. The newly designed TPE-based tetraimidazole donor 19 has been treated with 180°/120° trans-Pt(II) acceptors which led to the coordination-driven self-assembly of 3D discrete molecular cages in aqueous medium (Figure 5

• in mind, Stang and co-workers constructed heteroleptic triangles via the assembly of a BINOL-based ditopic ligand and 180° trans-Pt(II) acceptors. The 3,3'-dipyridyl-substituted chiral BINOL donor (S)-37 has a bite angle of 60° and when treated with linear 180° acceptors 38 and 39, it produced the

Tetraphenylethylene-embedded pillar[5]arene-based orthogonal self-assembly for efficient photocatalysis in water

• Zhihang Bai,
• Krishnasamy Velmurugan,
• Xueqi Tian,
• Minzan Zuo,
• Kaiya Wang and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2022, 18, 429–437, doi:10.3762/bjoc.18.45

• supramolecular assembly with a two-step FRET process by the utilization of a metallacycle-tetraphenylethylene (TPE) donor and eosin Y (EsY) and sulforhodamine (SR101) as first and second acceptors, respectively. The resulting supramolecular energy transfer system was applied to the alkylation of C–H bonds via a

• acceptors. The obtained vesicles could be utilized as a nanoreactor for photocatalyzed dehalogenation reactions in water. However, the above reported supramolecular nanosystem requires a long time to produce the dehalogenated product with high yield. Therefore, the development of a potential nanoreactor for

Unexpected chiral vicinal tetrasubstituted diamines via borylcopper-mediated homocoupling of isatin imines

• Marco Manenti,
• Leonardo Lo Presti,
• Giorgio Molteni and
• Alessandra Silvani

Beilstein J. Org. Chem. 2022, 18, 303–308, doi:10.3762/bjoc.18.34

• units. Such the C2–C10 single bond is quite long (1.58 Å), as expected due to crowding of the two facing oxindole systems. In the crystal, NH groups set up intramolecular hydrogen bonds with the O acceptors of the sulfinamide moieties (see Table 2), likely contributing to further stabilize the observed

N-Sulfinylpyrrolidine-containing ureas and thioureas as bifunctional organocatalysts

• Viera Poláčková,
• Dominika Krištofíková,
• Boglárka Némethová,
• Renata Górová,
• Mária Mečiarová and
• Radovan Šebesta

Beilstein J. Org. Chem. 2021, 17, 2629–2641, doi:10.3762/bjoc.17.176

• ) was reacted with 4-fluoro-β-nitrostyrene (7c). In the presence of catalyst (S,R)-C2 only traces of product 8f (THF/H2O, NMM as the base, and additive PhCO2H) were obtained (Scheme 3). Michael acceptors containing heterocyclic groups have been studied only sparingly, but the corresponding chiral

• compounds with heterocyclic substituents are of high biological and medicinal relevance [34][35]. Therefore, we have decided to evaluate sulfinylurea and thiourea catalysts C1 and C2 also with (E)-2-(2-nitrovinyl)furan (9) and (E)-3-(2-nitrovinyl)pyridine (11) as Michael acceptors. As Michael donor, we

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

• of prolinol silyl ether (cat. 120) and benzoic acid (A1) catalysts to bring about reaction between 3-formyl-substituted indoles or pyrroles 118 and diverse electrophiles, including carbonyls, imines and other Michael acceptors (Scheme 5) [69]. The reaction with secondary amines occurred via the

In-depth characterization of self-healing polymers based on π–π interactions

• Josefine Meurer,
• Julian Hniopek,
• Johannes Ahner,
• Michael Schmitt,
• Jürgen Popp,
• Stefan Zechel,
• Kalina Peneva and
• Martin D. Hager

Beilstein J. Org. Chem. 2021, 17, 2496–2504, doi:10.3762/bjoc.17.166

• -moieties act as both π-donors and -acceptors. Weakening of π–π interactions therefore results in higher electron densities in some part of the perylene moiety, while in other parts the electron density decreases. The C=O vibrations at 1656 and 1698 cm−1 on the other hand both shift to higher wavenumbers

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

• in Scheme 22). Conclusion 1,3-Enynes, one of the most significant classes of Michael acceptors for the construction of N-heterocycles, have been widely used in organic synthesis. We herein reviewed the recent advances in the development of tandem cyclization reactions of 1,3-enynes in the presence of

(Phenylamino)pyrimidine-1,2,3-triazole derivatives as analogs of imatinib: searching for novel compounds against chronic myeloid leukemia

• Luiz Claudio Ferreira Pimentel,
• Lucas Villas Boas Hoelz,
• Henayle Fernandes Canzian,
• Frederico Silva Castelo Branco,
• Andressa Paula de Oliveira,
• Vinicius Rangel Campos,
• Floriano Paes Silva Júnior,
• Rafael Ferreira Dantas,
• Jackson Antônio Lamounier Camargos Resende,
• Anna Claudia Cunha,
• Nubia Boechat and
• Mônica Macedo Bastos

Beilstein J. Org. Chem. 2021, 17, 2260–2269, doi:10.3762/bjoc.17.144

• original work that led to compound 3, and, additionally, they are able to act as acceptors and donors in hydrogen bonds and thus were expected to increase the aqueous solubility of the compounds. Additionally, Kalesh and co-workers demonstrated good results with derivative 4 which contains the amide group

Chemical syntheses and salient features of azulene-containing homo- and copolymers

• Vijayendra S. Shetti

Beilstein J. Org. Chem. 2021, 17, 2164–2185, doi:10.3762/bjoc.17.139

• for 81 and 0.24 cm2 V−1 s−1 for 83. The polymer 81 with an electron mobility of 0.42 cm2 V−1 s−1 represents one of the best unipolar n-type polymers for OFET applications. These polymers were also tested as electron acceptors for all-polymer solar cell (PSC) devices, and 81 in particular, showed a

Enantioenriched α-substituted glutamates/pyroglutamates via enantioselective cyclopropenimine-catalyzed Michael addition of amino ester imines

• Zara M. Seibel,
• Jeffrey S. Bandar and
• Tristan H. Lambert

Beilstein J. Org. Chem. 2021, 17, 2077–2084, doi:10.3762/bjoc.17.134

• -substituted glutamate derivatives is via the Michael addition of α-amino ester enolates to acrylate acceptors. These products can also be easily converted to pyroglutamates by lactamization [28][29][30]. Although the use of substituted amino ester derivatives for the enantioselective α-alkylation has been

A study on selective transformation of norbornadiene into fluorinated cyclopentane-fused isoxazolines

• Zsanett Benke,
• Attila M. Remete and
• Loránd Kiss

Beilstein J. Org. Chem. 2021, 17, 2051–2066, doi:10.3762/bjoc.17.132

• observed selectivities in metathesis reactions, H-bonding interactions between chloride ligands as H-bond acceptors and OH or NH functions in the metathesis intermediate appear to be determining [35][36]. Selectivity derived from chelation is considered to be an another important contributor. Through the

Progress and challenges in the synthesis of sequence controlled polysaccharides

• Giulio Fittolani,
• Theodore Tyrikos-Ergas,
• Denisa Vargová,
• Manishkumar A. Chaube and
• Martina Delbianco

Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129

• enzymes cannot distinguish between acceptors with different lengths in the reaction mixture. Chemical polymerization is often performed by ring-opening of the respective anhydrosugar (Figure 1B) or polycondensation reactions. This approach is highly valuable to generate long chains in short time, allowing

• polysaccharides). To date, the longest xylans reported are 10mers [205], although there is in principle no reason hindering the synthesis of longer structures. A convergent approach is often employed to avoid tedious purification of unreacted acceptors from the products, resulting from incomplete glycosylation

• . Peracetylated thioglycoside donors 52 were reacted with 4-methylbenzoylated (MBz) acceptors 53, following NIS/AgOTf activation (Scheme 7C). Upon global deprotection, a collection of well-defined oligoxylans with 4–10 monosaccharide units was obtained [205]. A convergent approach was also employed to prepare a β

Electron-rich triarylphosphines as nucleophilic catalysts for oxa-Michael reactions

• Susanne M. Fischer,
• Simon Renner,
• A. Daniel Boese and
• Christian Slugovc

Beilstein J. Org. Chem. 2021, 17, 1689–1697, doi:10.3762/bjoc.17.117

• triphenylphosphine (TPP) in catalyzing oxa-Michael additions. A matrix consisting of three differently strong Michael acceptors and four alcohols of varying acidity was used to assess the activity of the three catalysts. All test reactions were performed with 1 mol % catalyst loading, under solvent-free conditions

• and at room temperature. The results reveal a decisive superiority of TMTPP for converting poor and intermediate Michael acceptors such as acrylamide and acrylonitrile and for converting less acidic alcohols like isopropanol. With stronger Michael acceptors and more acidic alcohols, the impact of the

• -Michael addition. Triphenylphosphine (TPP), (4-methoxyphenyl)diphenylphosphine (MMTPP) and tris(4-trimethoxyphenyl)phosphine (TMTPP). The catalysts were investigated in the reaction of four different Michael acceptors with four different alcohols. In the oxa-Michael addition, the zwitterion i, initially

Methodologies for the synthesis of quaternary carbon centers via hydroalkylation of unactivated olefins: twenty years of advances

• Thiago S. Silva and
• Fernando Coelho

Beilstein J. Org. Chem. 2021, 17, 1565–1590, doi:10.3762/bjoc.17.112

• substrates will be reviewed, so electron-deficient olefins like Michael acceptors and even conjugate dienes will not be included in this review. Some examples of hydroallylation reactions have been included since these reactions, like hydroalkylation reactions, also form a new C(sp3)–C(sp3) bond at the

• substituents. Electron-withdrawing groups render the generated radical more susceptible to reaction with electron-rich compounds, whereas substituents that donate electronic density increase the addition reaction rate to electron-deficient ones (Michael acceptors, for example) [55]. Another beneficial aspect

• in Fe(III)-promoted hydroalkylation/cyclization cascades (Scheme 26A) [93]. Here, the carbocyclization occurred via a SN2 mechanism between the enolate intermediate and the tethered halide (Scheme 26B). Using arylidene diones 67 as radical acceptors, spiro compounds 69 were obtained in moderate to

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Metal-free glycosylation with glycosyl fluorides in liquid SO₂

• Krista Gulbe,
• Jevgeņija Lugiņina,
• Edijs Jansons,
• Artis Kinens and
• Māris Turks

Beilstein J. Org. Chem. 2021, 17, 964–976, doi:10.3762/bjoc.17.78

• armed and disarmed glucose and mannose-derived glycosyl fluorides in moderate to excellent yields. A series of pivaloyl-protected O- and S-mannosides, as well as one example of a C-mannoside, are synthesized to demonstrate the scope of the glycosyl acceptors. The formation of the fluorosulfite species

• glycoconjugates [1][2][3][4]. Due to the large diversity of glycosyl donors and acceptors there is no general glycosylation method developed so far. To ensure high yielding, as well as regio- and stereoselective glycosidic bond formation, a proper combination of glycosyl donor and acceptor, protecting and leaving

• -glycosides to demonstrate the scope of acceptors compatible with our glycosylation conditions (Scheme 1). Most of the primary alcohols (2a, 2d–3f) were glycosylated in high yields (up to 91%). In the case of less reactive secondary alcohols (2b, 2h, 2j, 2k) and phenol (2l) better yields were obtained when

Simulating the enzymes of ganglioside biosynthesis with Glycologue

• Andrew G. McDonald and
• Gavin P. Davey

Beilstein J. Org. Chem. 2021, 17, 739–748, doi:10.3762/bjoc.17.64

• then to subsequent ceramide-linked glycoconjugate acceptors, before transport and eventual incorporation into the plasma membrane via vesicular fusion. Gangliosides, which function as antigenic determinants [4], may play a role in membrane organization [5], cell signaling [6], apoptosis [7], and in