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

In silico rationalisation of selectivity and reactivity in Pd-catalysed C–H activation reactions

• Liwei Cao,
• Mikhail Kabeshov,
• Steven V. Ley and
• Alexei A. Lapkin

Beilstein J. Org. Chem. 2020, 16, 1465–1475, doi:10.3762/bjoc.16.122

• mild conditions [13]. In particular, reactions involving palladium-catalysed activation of sp2 or sp3 C–H bonds of arenes or alkanes have been extensively investigated due to their wide scope and functional group tolerance [14]. A number of different mechanisms are proposed in the literature

An overview on disulfide-catalyzed and -cocatalyzed photoreactions

• Yeersen Patehebieke

Beilstein J. Org. Chem. 2020, 16, 1418–1435, doi:10.3762/bjoc.16.118

• alkanes provided an efficient protocol for the synthesis of alkanes from carboxylic acid substrates previously inaccessible through other methods. The mechanism of this reaction is similar to the previously proposed mechanism in Scheme 19. Isomerization reactions Thiyl radical-mediated isomerizations of C

Photocatalysis with organic dyes: facile access to reactive intermediates for synthesis

• Stephanie G. E. Amos,
• Marion Garreau,
• Luca Buzzetti and
• Jerome Waser

Beilstein J. Org. Chem. 2020, 16, 1163–1187, doi:10.3762/bjoc.16.103

• hydrogen atom source (PhSH). The reaction allows the direct conversion of carboxylic acids, e.g., 3.1 to the corresponding alkanes, e.g., 3.2. The scope includes carboxylic acids that were previously recalcitrant to other oxidative photocatalytic decarboxylations due to their high oxidation potential

Recent advances in Cu-catalyzed C(sp³)–Si and C(sp³)–B bond formation

• Balaram S. Takale,
• Ruchita R. Thakore,
• Elham Etemadi-Davan and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2020, 16, 691–737, doi:10.3762/bjoc.16.67

• decade later, Molander et al. made use of the same disilane as a source of the nucleophile for additions to α,β-unsaturated alkenes and alkynes as Michael acceptors bearing sulfones, nitriles, cyano, amido, and carboxyl ester groups to form β-silylated alkanes and alkenes in good to moderate yields [55

Cascade trifluoromethylthiolation and cyclization of N-[(3-aryl)propioloyl]indoles

• Ming-Xi Bi,
• Shuai Liu,
• Yangen Huang,
• Xiu-Hua Xu and
• Feng-Ling Qing

Beilstein J. Org. Chem. 2020, 16, 657–662, doi:10.3762/bjoc.16.62

• the direct incorporation of the SCF3 group into organic compounds [9][10][11][12][13][14][15][16], such as alkynes, alkenes, arenes, and alkanes. Despite these impressive advances, there is a continued strong demand for new methods that enable the efficient synthesis of SCF3-containing compounds

Synthesis, liquid crystalline behaviour and structure–property relationships of 1,3-bis(5-substituted-1,3,4-oxadiazol-2-yl)benzenes

• Afef Mabrouki,
• Malek Fouzai,
• Armand Soldera,
• Abdelkader Kriaa and
• Ahmed Hedhli

Beilstein J. Org. Chem. 2020, 16, 149–158, doi:10.3762/bjoc.16.17

• , which generates a lamellar packing and thus contributes to smectic phase stability [14]. It was reported that even simple n-alkanes containing a fluorocarbon block produces smectic phases [15][16][17][18][19]. Some molecules having only a single aromatic ring and fluorinated tail show smectic phases

Analysis of sesquiterpene hydrocarbons in grape berry exocarp (Vitis vinifera L.) using in vivo-labeling and comprehensive two-dimensional gas chromatography–mass spectrometry (GC×GC–MS)

• Philipp P. Könen and
• Matthias Wüst

Beilstein J. Org. Chem. 2019, 15, 1945–1961, doi:10.3762/bjoc.15.190

• ], while [6,6,6-2H3]-(±)-mevalonolactone (d3-MVL) was purchased from C/D/N Isotopes Inc. (Pointe-Claire, Quebec, Canada). Retention indices were calculated using a C7–C30 saturated alkanes standard solution obtained from Sigma-Aldrich (St. Louis, MO, U.S.A.). The analytical standard (+)-valencene (purity

• mass spectra with those of the NIST database (when available), taking into account the match factors and reverse match factors. A series of n-alkanes (C7–C30) were analyzed. The retention times of the measured n-alkanes on the first GC column were used to calculate the retention indices I according to

Transient and intermediate carbocations in ruthenium tetroxide oxidation of saturated rings

• Manuel Pedrón,
• Laura Legnani,
• Maria-Assunta Chiacchio,
• Pierluigi Caramella,
• Tomás Tejero and
• Pedro Merino

Beilstein J. Org. Chem. 2019, 15, 1552–1562, doi:10.3762/bjoc.15.158

• carbocation. In the case of pyrrolidines, the carbocation is completely stabilized as an energy minimum in the form of an iminium ion and the reaction takes place in two steps. Keywords: alkanes; carbocations; DFT; oxidations; ruthenium tetroxide; Introduction Ruthenium-catalyzed oxidations [1][2] and, in

• some chemical behavior. Indeed, further theoretical studies on MD simulations would be needed to elucidate the lifetime of the transient carbocation [34][35]. These results demonstrate the one-step-two-stage character [42] of the ruthenium oxidations of alkanes in which H transfer and O–C bond

• analysis). Energy profile for the oxidation of R4 and R5. Relative energies, calculated at the B3LYP-d3bj/Def2TZVP/cpcm=water level of theory, are given in kcal/mol. Optimized (B3LYP-d3bj/Def2SVP/cpcm=water) transition structures for the oxidation of R4 and R5. Oxidation of alkanes with RuO4. Mechanisms

Formation of an unexpected 3,3-diphenyl-3H-indazole through a facile intramolecular [2 + 3] cycloaddition of the diazo intermediate

• Andrew T. King,
• Hugh G. Hiscocks,
• Lidia Matesic,
• Mohan Bhadbhade,
• Roger Bishop and
• Alison T. Ung

Beilstein J. Org. Chem. 2019, 15, 1347–1354, doi:10.3762/bjoc.15.134

• structures stabilised by multiple tert-butyl groups [20][21], multi-ring cage hydrocarbons [22][23], and linear alkanes [22][23]. The interaction was found to be attractive in all these cases, and computational justifications have been published [21][23]. It, therefore, appears probable that, despite their

Mechanochemistry of supramolecules

• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2019, 15, 881–900, doi:10.3762/bjoc.15.86

• capsule 40 formed through hydrogen-bonding and the cavity was found to be able to encapsulate different organic molecules such as alkanes, acids, amines, etc. The encapsulation of a [2.2]paracyclophane in the cage was achieved by ball milling at 30 Hz (Figure 22) and the host–guest product 40 was verified

Selective benzylic C–H monooxygenation mediated by iodine oxides

• Kelsey B. LaMartina,
• Haley K. Kuck,
• Linda S. Oglesbee,
• Asma Al-Odaini and
• Nicholas C. Boaz

Beilstein J. Org. Chem. 2019, 15, 602–609, doi:10.3762/bjoc.15.55

• widely used in industrial processes as promoters of autoxidation in the functionalization of benzylic C–H bonds of aryl alkanes, such as in the synthesis of terephthalic acid from p-xylene [21]. Metal-free oxidants have been used in benzylic C–H to C–O functionalization. Specifically, the use of

• NO and HNO3 [46][47][48]. In the work that follows, we report the selective monooxygenation of secondary benzylic C–H bonds of simple aryl alkanes using a combination of iodate and catalytic N-hydroxyphthalimide (NHPI), which complements the selectivity and capabilities of existing published work

Metal-free C–H mercaptalization of benzothiazoles and benzoxazoles using 1,3-propanedithiol as thiol source

• Yan Xiao,
• Bing Jing,
• Xiaoxia Liu,
• Hongyu Xue and
• Yajun Liu

Beilstein J. Org. Chem. 2019, 15, 279–284, doi:10.3762/bjoc.15.24

• [22] and 1,2-ethanedithiol [23]. In the past decades, C–H functionalization has become an effective strategy for constructing different molecules directly from simple arenes and alkanes. C–H functionalization is an important method for C–S coupling reactions [24][25]. For example, transition metal

Adhesion, forces and the stability of interfaces

• Robin Guttmann,
• Johannes Hoja,
• Christoph Lechner,
• Reinhard J. Maurer and
• Alexander F. Sax

Beilstein J. Org. Chem. 2019, 15, 106–129, doi:10.3762/bjoc.15.12

• among alkane molecules in liquid alkanes gives a strong favorable transfer energy for passage of an alkane from vapor into liquid alkane”, explaining the poor solubility of hydrocarbons in water and the good solubility of alkane molecules in liquid alkane [11]. Nonetheless, this interaction is nothing