Construction of hexabenzocoronene-based chiral nanographenes

• Ranran Li,
• Di Wang,
• Shengtao Li and
• Peng An

Beilstein J. Org. Chem. 2023, 19, 736–751, doi:10.3762/bjoc.19.54

• ], and nanoribbons [19]. Meanwhile, to modulate the properties of synthetic hydrocarbon NGs, a variety of heteroatom-doped NGs have been constructed [8]. Chirality is a fundamental phenomenon in nature and plays an important role in science, especially in living systems. The chirality in chemistry refers

• octagon-containing carbo[5]helicene was isolated in a 61% yield, which can be further transformed into other chiral hydrocarbon analogues 12 and 13 [35]. Chiral resolution of these helicenes was accomplished by chiral high-performance liquid chromatography (HPLC) and the isomerization barriers were

• nanographene 96. And the trilayer nanographene 100 containing two oxa[6]helicenes was obtained through a synthetic route similar to that of 96. The structure of hydrocarbon NG 96 exhibited a typical overlapped structure with an interlayer distance of 4.1 Å and consisted of two [8]helicenes as the linker

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

• those with hydrocarbon, ether, acetal, and ester functionalities; although, aniline nucleophiles only resulted in the one step asymmetric ring-opening (ARO) product under the standard reaction conditions. Fortunately, the authors noted the addition of triethylamine allowed for aniline nucleophiles to

Germacrene B – a central intermediate in sesquiterpene biosynthesis

• Houchao Xu and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 186–203, doi:10.3762/bjoc.19.18

• potentially arise from the achiral sesquiterpene hydrocarbon germacrene B. Not only compounds isolated from natural sources, but also synthetic compounds are dicussed, with the aim to give a rationale for the structural assignment for each compound. A total number of 64 compounds is presented, with 131 cited

• is terminated by deprotonation to yield a terpene hydrocarbon or by nucleophilic attack of water to generate a terpene alcohol. For the precursor of sesquiterpenes FPP six initial cyclisation modes are possible (Scheme 1). After ionisation to A either a 1,10-cyclisation to the (E,E)-germacradienyl

• dehydration of (−)-1(10)-valencen-7β-ol (35) (Scheme 10C) [92], but has not been isolated from natural sources. Compound 22 could be formed from I1a by Wagner–Meerwein rearrangement to I1c and deprotonation (Scheme 7). This hydrocarbon ([α]D22 = +26, c 0.06) has been obtained as a dehydration product of

Nostochopcerol, a new antibacterial monoacylglycerol from the edible cyanobacterium Nostochopsis lobatus

• Naoya Oku,
• Saki Hayashi,
• Yuji Yamaguchi,
• Hiroyuki Takenaka and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2023, 19, 133–138, doi:10.3762/bjoc.19.13

• HSQC spectra and these structural pieces were assembled into four spin systems by the COSY correlations: an ethyl group (C16–C15), a C8 internal hydrocarbon chain with two degrees of unsaturation (C12–C11=C10–C9–C8=C7–C6–C5), three consecutive methylenes (C4–C3–C2) with a carboxy-termination, and a

1,4-Dithianes: attractive C2-building blocks for the synthesis of complex molecular architectures

• Bram Ryckaert,
• Ellen Demeyere,
• Frederick Degroote,
• Hilde Janssens and
• Johan M. Winne

Beilstein J. Org. Chem. 2023, 19, 115–132, doi:10.3762/bjoc.19.12

• reported far less commonly than their use in (4 + 3) cycloadditions [94]. Simple hydrocarbon allyl cations can also undergo (3 + 2) cycloadditions through a purely stepwise cation olefin cyclization-type pathway, but these generally give complex mixtures and low yields and show unpredictable substrate

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

• organic syntheses [5][6][7][8][9] and offer rich opportunities for the adaptation of organocatalysis. The diversity of such transformations spans from the functionalization of hydrocarbon raw materials to the fine organic synthesis, including functional group transformations, oxidative cyclizations, and

• the hydrocarbon cyclic structure making the NO reactive center more sterically available [97] or by the introduction of electron-withdrawing groups (electronically tuned nitroxyl radical catalysis) [98][99][100]. More recently, the application of chiral electronically tuned nitroxyl radicals for the

Navigating and expanding the roadmap of natural product genome mining tools

• Friederike Biermann,
• Sebastian L. Wenski and
• Eric J. N. Helfrich

Beilstein J. Org. Chem. 2022, 18, 1656–1671, doi:10.3762/bjoc.18.178

• , terpene cyclases generate the oftentimes multicyclic, hydrocarbon scaffold via a carbocation-mediated cascade reaction [30]. Terpene cyclases are obligatory components of canonical terpene pathways and are used to identify terpene BGCs (Figure 3B) [30][31]. RiPPs, on the other hand, lack genes that are

1,4,6,10-Tetraazaadamantanes (TAADs) with N-amino groups: synthesis and formation of boron chelates and host–guest complexes

• Artem N. Semakin,
• Ivan S. Golovanov,
• Yulia V. Nelyubina and
• Alexey Yu. Sukhorukov

Beilstein J. Org. Chem. 2022, 18, 1424–1434, doi:10.3762/bjoc.18.148

• , the preparation of trisubstituted adamantanes is challenging because multiple functionalization of the parent hydrocarbon is not selective, while the synthesis from acyclic precursors requires multistep synthetic routes [10][14]. The use of azaadamantanes is more advantageous as they are prepared via

Characterization of a new fusicoccane-type diterpene synthase and an associated P450 enzyme

• Jia-Hua Huang,
• Jian-Ming Lv,
• Liang-Yan Xiao,
• Qian Xu,
• Fu-Long Lin,
• Gao-Qian Wang,
• Guo-Dong Chen,
• Sheng-Ying Qin,
• Dan Hu and
• Hao Gao

Beilstein J. Org. Chem. 2022, 18, 1396–1402, doi:10.3762/bjoc.18.144

• , implying that TadA can catalyze the formation of a diterpene hydrocarbon (Supporting Information 1, Figure S1). The crude extract was also subjected to high-performance liquid chromatography–mass spectrometry (HPLC–MS) analysis. It showed that introduction of tadA led to the generation of two products 1

Polymer and small molecule mechanochemistry: closer than ever

• José G. Hernández

Beilstein J. Org. Chem. 2022, 18, 1225–1235, doi:10.3762/bjoc.18.128

• mechanically labile bonds or not, and whether it is a hydrocarbon [50], contains heteroatoms [51], or is inorganic in nature. With regards to the latter, ceramic piezoelectric materials such as barium titanate (BaTiO3) or zinc oxide (ZnO) are materials that can accumulate electric charge in the structure in

Enzymes in biosynthesis

• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2022, 18, 1131–1132, doi:10.3762/bjoc.18.116

• proceed through multistep cationic cascade reactions and usually produce a polycyclic terpene hydrocarbon or alcohol with multiple stereogenic centers. While these transformations require only a single enzyme, polyketide and nonribosomal peptide biosyntheses are catalyzed by megasynthases that follow an

Understanding the competing pathways leading to hydropyrene and isoelisabethatriene

• Shani Zev,
• Marion Ringel,
• Ronja Driller,
• Bernhard Loll,
• Thomas Brück and
• Dan T. Major

Beilstein J. Org. Chem. 2022, 18, 972–978, doi:10.3762/bjoc.18.97

• , is that in the HP pathway C1–C10 cyclization occurs immediately, while in the IE pathway a substrate transoid to cisoid conformational change occurs, shifting the covalent attachment point (i.e., C1 to C3) between the substrate hydrocarbon and the pyrophosphate group [7] (Figure 1). Presumably, this

Electrochemical and spectroscopic properties of twisted dibenzo[g,p]chrysene derivatives

• Tomoya Imai,
• Ryuhei Akasaka,
• Naruhiro Yoshida,
• Toru Amaya and
• Tetsuo Iwasawa

Beilstein J. Org. Chem. 2022, 18, 963–971, doi:10.3762/bjoc.18.96

• , a strong photoluminescence was observed for DBC-H and DBC-Si. Keywords: DFT calculation; dibenzo[g,p]chrysenes; fluorescent compounds; oxidation; polycyclic aromatic hydrocarbon (PAH); twisted acenes; Introduction Polycyclic aromatic hydrocarbons (PAHs) have attracted interest as potential

The stereochemical course of 2-methylisoborneol biosynthesis

• Binbin Gu,
• Anwei Hou and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2022, 18, 818–824, doi:10.3762/bjoc.18.82

• formation of 1 (Scheme 3). In contrast to the product distribution from (R)-2-Me-LPP with 1 as the main and 10 as a side product of 2MIBS, the hydrocarbon 10 is formed from (S)-2-Me-LPP in slightly larger amounts than 1, which could be explained by an incorrect placing or incomplete binding of the active

Peptide stapling by late-stage Suzuki–Miyaura cross-coupling

• Hendrik Gruß,
• Rebecca C. Feiner,
• Ridhiwan Mseya,
• David C. Schröder,
• Michał Jewgiński,
• Kristian M. Müller,
• Rafał Latajka,
• Antoine Marion and
• Norbert Sewald

Beilstein J. Org. Chem. 2022, 18, 1–12, doi:10.3762/bjoc.18.1

• stapling and the most prominent methodology was developed by the groups of Grubbs and Verdine using ring-closing metathesis (RCM) [4][5][6]. The optimised protocol for these so-called hydrocarbon-stapled peptides uses α-methyl-, α-alkenylglycines in a distance of i, i + 3/i + 4 for one helix turn or i, i

• part in the destruction complex for β-catenin labelling in the canonical Wnt signalling. Loss-of-function mutations in this pathway lead to a dysregulated signal transduction causing cancer [75][76]. All-hydrocarbon stapled peptides comprising amino acids 467 to 481 of the axin CBD had been studied in

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

• Vijayendra S. Shetti Department of Chemistry, National Institute of Technology Karnataka, Surathkal 575025, India 10.3762/bjoc.17.139 Abstract Azulene is a non-alternant, aromatic hydrocarbon with many exciting characteristics such as having a dipole moment, bright color, stimuli responsiveness

• -containing homo- and copolymers, including brief descriptions of their key properties. Keywords: azulene; chemical synthesis; copolymer; non-alternant hydrocarbon; organic electronics; polyazulene; Introduction Azulene (C10H8) is a non-alternant, non-benzenoid, 10 π electron aromatic hydrocarbon containing

• , violating Kasha’s rule [6]. These intriguing features have encouraged researchers to use azulene derivatives as functional organic molecules in the field of optoelectronics [7][8][9][10][11][12][13][14]. Employing such stimuli-responsive, non-alternant hydrocarbon with odd-membered rings in the chemical

Recent advances in the syntheses of anthracene derivatives

• Giovanni S. Baviera and
• Paulo M. Donate

Beilstein J. Org. Chem. 2021, 17, 2028–2050, doi:10.3762/bjoc.17.131

• years (2008–2020) and focuses on direct and indirect methods to construct anthracene and anthraquinone frameworks. Keywords: anthracenes; anthraquinones; Friedel–Crafts cyclization; intramolecular cyclization; metal-catalyzed; Introduction Anthracene is an important aromatic hydrocarbon consisting of

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

• heterogeneous vanadium-based catalysts have been employed to obtain alcohols and carbonyl compounds through oxidation, including VOSO4, Na(VO3), VO(acac)2, VOX3, among others. Obtaining ketones and aldehydes from hydrocarbon compounds through vanadium-mediated activation of C(sp3)–H bonds in a benzylic position

Cationic oligonucleotide derivatives and conjugates: A favorable approach for enhanced DNA and RNA targeting oligonucleotides

• Mathias B. Danielsen and
• Jesper Wengel

Beilstein J. Org. Chem. 2021, 17, 1828–1848, doi:10.3762/bjoc.17.125

• synthesis and coupling efficiency on the synthesizer, significant loss of the hydrocarbon-linked group was observed during the alkaline deprotection conditions [115]. After insertion into a 19-mer DNA-ON, modification 79 did not show any significant increase in Tm. This trend was changed when the

Recent advances in the application of isoindigo derivatives in materials chemistry

• Andrei V. Bogdanov and
• Vladimir F. Mironov

Beilstein J. Org. Chem. 2021, 17, 1533–1564, doi:10.3762/bjoc.17.111

• cells was shown [37]. Thus, the hexyl and octyl derivatives 25a,b showed the best PCE values of 5.1 and 5.2%, respectively, which is higher than analogues bearing a longer or branched hydrocarbon chain (Scheme 15 and Table 5). If the OSC active layer is prepared with the addition of diiodooctane, the

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

• ”, formally an internal redox reaction where the heterocyclic system is oxidatively aromatized and one of the substituents at C-4 reductively lost as a hydrocarbon. The reaction involves the treatment of a ketone with a solution of ethylcyanoacetate in ethanolic ammonia [7]. A precipitate of the ammonium salt

• ammonium salt of the dicyanoimide. A similar bubbling could be observed when the crystallized imide was treated with ammonia. Guareschi collected the gas evolved from the reaction, and much to his surprise, identified it as the hydrocarbon corresponding to the more substituted alkyl residue of the starting

• terms of overall redox transformation, the reaction formally “hydrolyses” a ketone into a hydrocarbon and a carboxylic acid, and the mechanism remained a black box for over a century, being eventually clarified only in 2007 by a team of British and Russian chemists [8]. One important starting

N-tert-Butanesulfinyl imines in the asymmetric synthesis of nitrogen-containing heterocycles

• Joseane A. Mendes,
• Paulo R. R. Costa,
• Miguel Yus,
• Francisco Foubelo and
• Camilla D. Buarque

Beilstein J. Org. Chem. 2021, 17, 1096–1140, doi:10.3762/bjoc.17.86

• methodologies for these compounds in the literature. In most cases, the pyrrolidine ring is formed from an amine with a hydrocarbon chain that also carries a functional group at the appropriate distance that allows the cyclization process to take place. In the case of substituted pyrrolidines, the

• . Starting imine 135 with two well-defined stereogenic centers at the hydrocarbon backbone were prepared as a mixture of (RS)- and (SS)-diastereoisomers from ᴅ-glutamic acid. After nucleophilic addition to the imine, a successive cyclization–desulfinylation occurred to give the corresponding piperidinone

Valorisation of plastic waste via metal-catalysed depolymerisation

• Francesca Liguori,
• Carmen Moreno-Marrodán and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2021, 17, 589–621, doi:10.3762/bjoc.17.53

• Polyolefins Due to the intrinsic chemical resistance of the hydrocarbon skeleton devoid of functional groups, polyolefins are neither prone to chemical recycling nor biodegradable [131][132]. Hence, they are more commonly repurposed via mechanical recycling, burned or just discarded [133][134

• in >97% yield into liquid hydrocarbon (alkane) products having a narrow distribution of the molecular weight (960–1130 g⋅mol−1) under 11.7 bar H2 at 300 °C and solvent-free conditions [146]. The pyrolysis oils produced may be used as lubricants, waxes or further processed into detergents and

• °C provided a hydrocarbon oil in 92% yield, 71.4% of which were attributable to styrene monomer [156]. A decrease of 56 kJ mol−1 for the activation energy of PS depolymerisation was calculated in the presence of the catalysts. More recently, high-porosity montmorillonite (Mt) was used to prepare Mg

Synthesis and physicochemical evaluation of fluorinated lipopeptide precursors of ligands for microbubble targeting

• Masayori Hagimori,
• Estefanía E. Mendoza-Ortega and
• Marie Pierre Krafft

Beilstein J. Org. Chem. 2021, 17, 511–518, doi:10.3762/bjoc.17.45

• hydrophobic chains (CnF2n+1, n = 6, 7, 8, 1–3) grafted through a lysine moiety on a hydrophilic chain composed of a lysine–serine–serine (KSS) sequence followed by 5 SG sequences. These F-lipopeptides are precursors of targeting lipopeptide conjugates. A hydrocarbon counterpart with a C10H21 chain (4) was

• interface, with equilibrium surface pressures reaching ≈7–10 mN m−1 versus less than 1 mN m−1 only for their hydrocarbon analog 4. The F-lipopeptides penetrate in the DPPC monolayers in both liquid expanded (LE) and liquid condensed (LC) phases without interfacial film destabilization. By contrast, 4

• . By contrast, the hydrocarbon lipopeptide led to microbubbles with a larger mean diameter and a significantly lower stability. Keywords: adsorption at fluid interfaces; drug delivery; microbubble targeting; molecular imaging; monolayer; perfluoroalkylated lipopeptide; solid-phase peptide synthesis

Biochemistry of fluoroprolines: the prospect of making fluorine a bioelement

• Vladimir Kubyshkin,
• Rebecca Davis and
• Nediljko Budisa

Beilstein J. Org. Chem. 2021, 17, 439–460, doi:10.3762/bjoc.17.40