(E,Z)-1,1,1,4,4,4-Hexafluorobut-2-enes: hydrofluoroolefins halogenation/dehydrohalogenation cascade to reach new fluorinated allene

• Nataliia V. Kirij,
• Andrey A. Filatov,
• Yurii L. Yagupolskii,
• Sheng Peng and
• Lee Sprague

Beilstein J. Org. Chem. 2024, 20, 452–459, doi:10.3762/bjoc.20.40

• the possibility of using it to obtain another allene. We found that 2-chloro-1,1,1,4,4,4-hexafluorobut-2-enes (6a,b) react with bromine under the influence of sunlight with the formation of 2,3-dibromo-2-chloro-1,1,1,4,4,4-hexafluorobutane 16 in 84% yield (Scheme 12). As in the case of alkanes 2 and 5

C–H bond functionalization: recent discoveries and future directions

• Indranil Chatterjee

Beilstein J. Org. Chem. 2023, 19, 1568–1569, doi:10.3762/bjoc.19.114

• feedstocks, the introduction of functionality at specific positions of molecules without requiring any prefunctionalized precursors, and the conversion of light alkanes to higher-value analogues [1][2]. The nonnecessity of prefunctionalization provides a step-economic alternative to classical reactions as

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

NaI/PPh₃-catalyzed visible-light-mediated decarboxylative radical cascade cyclization of N-arylacrylamides for the efficient synthesis of quaternary oxindoles

• Dan Liu,
• Yue Zhao and
• Frederic W. Patureau

Beilstein J. Org. Chem. 2023, 19, 57–65, doi:10.3762/bjoc.19.5

• /cyclization cascades from acrylamides for the synthesis of oxindoles [39][40][41]. The radicals are typically generated from alkyl halides [42][43][44], carboxylic acids [45][46][47], simple alkanes [48], alkylboronic acids [49], isocyanides [50], or other [51][52][53]. In this context, the group of Fu

Modern flow chemistry – prospect and advantage

• Philipp Heretsch

Beilstein J. Org. Chem. 2023, 19, 33–35, doi:10.3762/bjoc.19.3

• pressurized gaseous alkanes employed in the abovementioned transformations. Enhanced safety profiles of continuous flow reactors have been widely appreciated in industrial laboratories, while hazardous reactions still tend to be addressed subordinately or are even marginalized in academia [9]. The comparably

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

• oxidation of substrates with activated CH-bonds, such as alkylarenes (Scheme 6). At higher temperatures, even unactivated alkanes can be functionalized [75][81]. The NHPI/Co(OAc)2 system was successfully employed for the selective oxidation of methylarenes to aromatic carboxylic acids [78] (in AcOH medium

• perform the CH-functionalization of alkanes by electron-deficient alkenes. Photoredox catalysis was employed for the one-electron oxidation of the DABCO-derived organocatalyst to the dication radical. The authors noted that the introduction of a substituent X near the radical center further improves the

• radical (SPyf, Scheme 24) was proposed as a hydrogen atom abstracting agent for unactivated C–H bonds of alkanes and other CH-reagents [123] (Scheme 24). It was generated by the irradiation of the corresponding disulfide with 400 nm LEDs. In the proposed catalytic cycle tetrafluoropyridinyl thiol HSPyf is

Synthesis of odorants in flow and their applications in perfumery

• Merlin Kleoff,
• Paul Kiler and
• Philipp Heretsch

Beilstein J. Org. Chem. 2022, 18, 754–768, doi:10.3762/bjoc.18.76

• and unactivated alkanes, including the transformation of isodihydrobenzofuran (47) to phthalide (50, Scheme 11) [44]. In this reaction, the decatungstate anion is activated by irradiation in a 3D-printed tube reactor using LED light with a wavelength of λ = 365 nm. It is assumed, that the photoexcited

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

Trichloroacetic acid fueled practical amine purifications

• Aleena Thomas,
• Baptiste Gasch,
• Enzo Olivieri and
• Adrien Quintard

Beilstein J. Org. Chem. 2022, 18, 225–231, doi:10.3762/bjoc.18.26

• isolated in its pure form starting from model mixtures containing various aromatics, phenols, alkanes or alkenes in overall purification yields ranging from 53 to 98%. The lower yields are observed for coordinating phenol and catechol (Table 2, entries 3 and 4), probably impacting the crystallization

Iron-catalyzed domino coupling reactions of π-systems

• Austin Pounder and
• William Tam

Beilstein J. Org. Chem. 2021, 17, 2848–2893, doi:10.3762/bjoc.17.196

• aromatic and cyano groups. The oxidation of species 80 would reduce the Fe catalyst back to its reduced form, while a tert-butyl alkoxide can furnish the final product through acid-base catalysis. In 2019, Li and co-workers investigated a three-component dialkylation of alkenes 82 with common alkanes 83

• examining of other potential arenes capable of undergoing electrophilic aromatic substitution would expand the applicability of the reaction. Carboazidation In 2018, Yang investigated the three-component carboazidation of styrene derivatives 115 with alkanes 101/139b and trimethylsilyl azide for the

Visible-light-mediated copper photocatalysis for organic syntheses

• Yajing Zhang,
• Qian Wang,
• Zongsheng Yan,
• Donglai Ma and
• Yuguang Zheng

Beilstein J. Org. Chem. 2021, 17, 2520–2542, doi:10.3762/bjoc.17.169

• functionalization of stable alkanes C(sp3)–H is generally difficult. In 2020, the König group [97] explored the photoinduced copperII catalyzed N–H alkylation of a broad range of nitrogen-containing compounds 61 with unactivated alkanes 62. A tert-butoxy radical abstracted a hydrogen atom from the alkane via the

Photoredox catalysis in nickel-catalyzed C–H functionalization

• Lusina Mantry,
• Rajaram Maayuri,
• Vikash Kumar and
• Parthasarathy Gandeepan

Beilstein J. Org. Chem. 2021, 17, 2209–2259, doi:10.3762/bjoc.17.143

• quantities of sodium tungstate were found to be beneficial for the formation of the desired cross-coupling products 77. The authors’ investigations suggested that tungstate is acting as a base rather than a photocatalyst. A variety of C–H substrates including unactivated alkanes, amines, and ethers were

• xanthone as the photocatalyst and NiCl2·6H2O as the nickel catalyst can efficiently catalyze the transformation of methylarenes 25 into arylacetic acids 91 under UV light irradiation (Scheme 47). Furthermore, the authors also applied this methodology to functionalize unactivated alkanes such as cyclohexane

• alkanes 16, alkenes 92, and aryl bromides 3 (Scheme 48) [140]. Here, TBADT enables the generation of alkyl radicals from various alkane substrates via a HAT process under near-ultraviolet light irradiation. Both cyclic and linear alkanes were found to be suitable under the reaction conditions. Linear

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

• [11][12], the 2,2’-bianthracene derivative 3 provides a green and fluorescent OLED [13], 2,2’-bianthracenyl (4) has been employed as an organic semiconductor in an OFET device [14], and di-n-alkoxyanthracenes have gelling properties with diverse solvents, mainly alkanes and alcohols [4]. Furthermore

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

• numbers. The V(II) and V(V) species are reducing and oxidizing agents, respectively, whereas V(IV) is often encountered, mainly in the form of dioxovanadium ion VO2+ center [76]. Vanadium-based compounds have been reported to mediate the oxidation of alkanes to alcohols and ketones [76]. The reactions are

• have been used as additives in these reactions and are suggested to act as ligands, assist proton transfer and promote the formation of oligovanadates by decreasing the pH value of the solution. The mechanisms of some vanadium-mediated oxidation reactions of alkanes have been studied, most of them

• reaction suggested it goes through a radical pathway. Similar to the oxidation of alkanes to give alcohols and carbonyl compounds, vanadium complexes have been reported to mediate the hydroxylation of arenes, including the obtaining of phenol from benzene. However, most mechanistic studies provided

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

• of the potential of ATR in olefin hydrofunctionalization is the methodology developed by the Liu group [119], in which a carbon-centered radical is generated from simple alkanes instead of the more usual halogenated compounds. The authors reported that, in the presence of dicumyl peroxide (DCP) as a

• radical initiator and a copper salt as an additive, the reaction between unactivated olefins and alkanes (in large excess, 50 mL/mmol) afforded anti-Markovnikov hydroalkylation products at high temperature (110 °C) (Scheme 37). Two examples of the synthesis of quaternary carbon centers were reported using

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

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

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

• scission of C–C bonds into radicals, which leads to a complex mixture of olefinic and cross-linked compounds [143]. In a few cases, good selectivity to a liquid fraction was achieved. For instance, nanostructured BaTiO3 doped with Pb provided a mixture of liquid products, which includes alkanes (73.4

Identification of volatiles from six marine Celeribacter strains

• Anuj Kumar Chhalodia,
• Jan Rinkel,
• Dorota Konvalinkova,
• Jörn Petersen and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2021, 17, 420–430, doi:10.3762/bjoc.17.38

• source temperature: 230 °C, 3) quadrupole temperature: 150 °C, and 4) electron energy: 70 eV. Retention indices were calculated from retention times in comparison to those of a homologous series of n-alkanes (C7–C40). General synthetic and analytical methods Reactions were carried out in oven-dried

Supramolecular polymers with reversed viscosity/temperature profile for application in motor oils

• Jan-Erik Ostwaldt,
• Christoph Hirschhäuser,
• Stefan K. Maier,
• Carsten Schmuck and
• Jochen Niemeyer

Beilstein J. Org. Chem. 2021, 17, 105–114, doi:10.3762/bjoc.17.11

• provide the desired RVT effect. However, for the desired application, a substantial solubility in motor oils is necessary. In this study, two motor oils were tested: Nynas NS8 (a motor oil based on naphthenic structures) and Nexbase 3020 (a motor oil based on C15 to C30 alkanes). Unfortunately, GCP

3-Acetoxy-fatty acid isoprenyl esters from androconia of the ithomiine butterfly Ithomia salapia

• Florian Mann,
• Daiane Szczerbowski,
• Lisa de Silva,
• Melanie McClure,
• Marianne Elias and
• Stefan Schulz

Beilstein J. Org. Chem. 2020, 16, 2776–2787, doi:10.3762/bjoc.16.228

• esters, minor amounts of alkanes and alkenes were present, as well as fatty acids. The latter occurred in varying amounts in the samples, maybe depending on variation in quality of the individual sample (see Tables S3 and S4, Supporting Information File 1). Acids are also present in other tissues of the

Recent developments in enantioselective photocatalysis

• Callum Prentice,
• James Morrisson,
• Andrew D. Smith and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2020, 16, 2363–2441, doi:10.3762/bjoc.16.197

Photosensitized direct C–H fluorination and trifluoromethylation in organic synthesis

• Shahboz Yakubov and
• Joshua P. Barham

Beilstein J. Org. Chem. 2020, 16, 2151–2192, doi:10.3762/bjoc.16.183

Lipophilicity trends upon fluorination of isopropyl, cyclopropyl and 3-oxetanyl groups

• Benjamin Jeffries,
• Zhong Wang,
• Robert I. Troup,
• Anaïs Goupille,
• Jean-Yves Le Questel,
• Charlene Fallan,
• James S. Scott,
• Elisabetta Chiarparin,
• Jérôme Graton and
• Bruno Linclau

Beilstein J. Org. Chem. 2020, 16, 2141–2150, doi:10.3762/bjoc.16.182

• contrast to the result observed for C1 (see above, Figure 3). As discussed in the Introduction, converting acyclic alkanes to cyclopropane equivalents is a frequently used tactic in medicinal chemistry. The pairwise comparison of the isopropyl with the cyclopropyl substructures is best discussed via Figure

When metal-catalyzed C–H functionalization meets visible-light photocatalysis

• Lucas Guillemard and
• Joanna Wencel-Delord

Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147