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

• reported by Liu and co-workers [130]. Here, stoichiometric quantities of quinuclidine were used to get optimal results. Carboxylation Over the past few decades, significant attention has been devoted to exploit carbon dioxide (CO2) as the C1 resource [131][132]. In particular, the C–H functionalization

• with CO2 is considered an attractive organic synthesis strategy in terms of sustainable aspects [133][134][135]. In 2019, Murakami and co-workers reported on the photoinduced carboxylation of C(sp3)–H bonds with CO2 under 1 atm pressure [136]. Here, the authors discovered that the combination of

• same time, the in situ-generated nickel(0) complex 21-VI combines with the benzylic radical 21-III, followed by CO2 insertion resulting in the nickel(I) carboxylate complex 21-VIII. The ketyl radical is deprotonated by the base, and then undergoes a SET with nickel(I) carboxylate complex 21-VIII to

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

Synthesis of 1-indolyl-3,5,8-substituted γ-carbolines: one-pot solvent-free protocol and biological evaluation

• Premansh Dudhe,
• Mena Asha Krishnan,
• Kratika Yadav,
• Diptendu Roy,
• Krishnan Venkatasubbaiah,
• Biswarup Pathak and
• Venkatesh Chelvam

Beilstein J. Org. Chem. 2021, 17, 1453–1463, doi:10.3762/bjoc.17.101

• Software, San Diego, CA). HeLa cell uptake study of γ-carboline 3ac A live-cell imaging experiment was performed with HeLa cells. The HeLa cells were placed in a 4-well confocal dish (cell count ≈ 100 cells per well) and incubated for 48 h at 37 °C under 5% CO2. After 3 h of incubation with carboline

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

• 10 is entirely due to mesomeric effects, as expressed by the possibility to formulate two identical resonance forms, 10a and 10b, for the undissociated system (Scheme 6). It has been remarked that life is basically a hydrogen transfer to carbon dioxide, outrageously approximated by the equation CO2

Photoinduced post-modification of graphitic carbon nitride-embedded hydrogels: synthesis of 'hydrophobic hydrogels' and pore substructuring

• Cansu Esen and
• Baris Kumru

Beilstein J. Org. Chem. 2021, 17, 1323–1334, doi:10.3762/bjoc.17.92

• , and a detailed overview has been reported by Shalom et.al. [19]. Facile tunability has rendered g-CN to be applied in visible-light-induced catalytic reactions such as water splitting [20][21][22], pollutant degradation [23][24][25][26], CO2 reduction [27][28][29], photonics [30][31] and polymer

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

• scale-up equating to prolonged run times. As a result, alternative support formats have been investigated. In this context there has been a growing interest in the use of functionalised hollow fibres including their application as membranes for gas separation [110] (e.g., CO2 absorption [111]) as they

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

• . reported a ″green″ glycosylation procedure by employing supercritical CO2 (scCO2) as a weakly Lewis acidic reaction medium [37]. The method was successfully applied for the synthesis of O-glycosides from disarmed glycosyl chlorides and bromides in the absence of additional promoter. Herein we disclose a

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

• Shivani Gulati,
• Stephy Elza John and
• Nagula Shankaraiah

Beilstein J. Org. Chem. 2021, 17, 819–865, doi:10.3762/bjoc.17.71

• plausible mechanism shown in Scheme 14 explains the formation of azomethine ylide B by condensation of isatin with amino acid followed by release of a molecule of CO2 via A. The imine B undergoes 1,3-dipolar cycloaddition with the dipolarophiles 39. The cyclization yields the desired product 40 of the three

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

• (heat) or chemical agents. Indeed, chemical recycling processes can be divided into two main categories: thermochemical and chemolytic routes. All of these processes may result in a variety of valuable products and the mixture thereof, including C1 molecules (CO, CO2, CH4), H2O and H2 due to complete

• and the possible product contamination by homogeneous catalysts [199]. The conventional catalysts for this reaction are EG-soluble metal acetates, the activity of which showed a decrease in the order Zn2+ > Mn2+ > Co2+, which was attributed to the diverse interaction between the metal cation promoter

• (dicyclophosphino)ethane) showed minimal improvements compared to the chloride salt catalyst [205]. The use of transition metal-substituted polyoxometallates (POMs), of the general formula K6SiW11MO39(H2O) (M = Zn2+, Mn2+, Co2+, Cu2+, Ni2+) [206][207], was also investigated [208]. The catalytic activity was found

A new and efficient methodology for olefin epoxidation catalyzed by supported cobalt nanoparticles

• Lucía Rossi-Fernández,
• Viviana Dorn and
• Gabriel Radivoy

Beilstein J. Org. Chem. 2021, 17, 519–526, doi:10.3762/bjoc.17.46

• determined by ICP-AES. The analysis of the XPS spectra in the Co 2p region was consistent with the presence of Co2+ and Co3+, with main binding energy peaks at 779.6 and 780.0 eV, along with satellite signal at approximately 786 eV, which in principle could be ascribed to Co3O4 species in the catalyst

CF₃-substituted carbocations: underexploited intermediates with great potential in modern synthetic chemistry

• Anthony J. Fernandes,
• Armen Panossian,
• Bastien Michelet,
• Agnès Martin-Mingot,
• Frédéric R. Leroux and
• Sébastien Thibaudeau

Beilstein J. Org. Chem. 2021, 17, 343–378, doi:10.3762/bjoc.17.32

• formation of allylic carbenium ions, such as 103 [81]. α-(Trifluoromethyl)alkynylcarbenium ions It has been reported that the complex of Co2(CO)6 and propargyl alcohols allows the facile generation of the corresponding propargylium ions (Nicholas reaction) in a relatively strong acidic medium (i.e., TFA

Selective synthesis of α-organylthio esters and α-organylthio ketones from β-keto esters and sodium S-organyl sulfurothioates under basic conditions

• Jean C. Kazmierczak,
• Roberta Cargnelutti,
• Thiago Barcellos,
• Claudio C. Silveira and
• Ricardo F. Schumacher

Beilstein J. Org. Chem. 2021, 17, 234–244, doi:10.3762/bjoc.17.24

• place in β-keto esters, which is followed by CO2 displacement under heating [61][62][63][64]. We assume that in our case, when only 2 equiv of base are used, the keto–enol tautomer intermediates undergo a hydrolysis–decarboxylation process preferentially to a retro-Claisen reaction. This process forms

Insight into functionalized-macrocycles-guided supramolecular photocatalysis

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

Beilstein J. Org. Chem. 2021, 17, 139–155, doi:10.3762/bjoc.17.15

• activity (618.3 mmol⋅g−1⋅h−1) and an excellent stability (with a turnover number (TON) of 6417 after 75 h). Moreover, when the electron donor 1,3-dimethyl-2-phenyl-1,3-dihydrobenzimidazole (BIH) was added, the hybrid material functioned as an efficient photocatalyst for the reduction of CO2 to CO with 0.26

• (c) EY. Republished with permission of The Royal Society of Chemistry from [30] (“Host–guest chemistry between cyclodextrin and a hydrogen evolution catalyst cobaloxime” by M. Kato et al., New J. Chem. vol. 43, © 2019); permission conveyed through Copyright Clearing Center, Inc. Conversion of CO2 to

The fluorescence of a mercury probe based on osthol

• Guangyan Luo,
• Zhishu Zeng,
• Lin Zhang,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2021, 17, 22–27, doi:10.3762/bjoc.17.3

• performance of fluorescent probes. As shown in Figure 1A, the selectivity of OST to common metal ions is monitored by the fluorescence spectrum (λex = 325 nm). OST exhibits a weak fluorescence intensity at λex = 406 nm. When adding different metal ions (Hg2+, Ca2+, Na+, Mg2+, Al3+, Cd2+, Cu2+, Pb2+, Ni2+, Co2

Controlled decomposition of SF₆ by electrochemical reduction

• Sébastien Bouvet,
• Bruce Pégot,
• Stéphane Sengmany,
• Erwan Le Gall,
• Eric Léonel,
• Anne-Marie Goncalves and
• Emmanuel Magnier

Beilstein J. Org. Chem. 2020, 16, 2948–2953, doi:10.3762/bjoc.16.244

• ][7]. On the other hand, SF6 is a greenhouse gas [8]. It has indeed a global warming potential (GWP) 22,000 times greater than CO2 [9]. From an industrial point of view, this requires efficient methods of recycling or destroying SF6. This last point implies, because of its great stability, the use of

Dawn of a new era in industrial photochemistry: the scale-up of micro- and mesostructured photoreactors

• Emine Kayahan,
• Mathias Jacobs,
• Leen Braeken,
• Leen C.J. Thomassen,
• Simon Kuhn,
• Tom van Gerven and
• M. Enis Leblebici

Beilstein J. Org. Chem. 2020, 16, 2484–2504, doi:10.3762/bjoc.16.202

• has already been proven to be successful [4]. These examples show that photochemistry is a viable alternative to conventional chemistry approaches. In addition to specialty chemicals and wastewater treatment, photochemical pathways can also be used for methanol production [5], N2 fixation [6], and CO2

• photoreactor. The main reasons for this increase was the high surface-area-to-volume ratio and better illumination of the monolithic photoreactor [56]. The monolithic photoreactor was shown to have a higher yield for the CO2 photoreduction compared to a cell-type reactor that had no channels. This was

The B & B approach: Ball-milling conjugation of dextran with phenylboronic acid (PBA)-functionalized BODIPY

• Patrizia Andreozzi,
• Lorenza Tamberi,
• Elisamaria Tasca,
• Gina Elena Giacomazzo,
• Marta Martinez,
• Mirko Severi,
• Marco Marradi,
• Stefano Cicchi,
• Sergio Moya,
• Giacomo Biagiotti and
• Barbara Richichi

Beilstein J. Org. Chem. 2020, 16, 2272–2281, doi:10.3762/bjoc.16.188

• ). The cells were maintained at 37 °C, with 5% CO2 in a humidified chamber. Cell viability MTT assay Cell mitochondrial activity was tested using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, which is based on the mitochondrial conversion of the tetrazolium salt into a

Synthetic approaches to bowl-shaped π-conjugated sumanene and its congeners

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 2212–2259, doi:10.3762/bjoc.16.186

• thermoelectric properties in addition to the onigiri-type core-shell assemblies have been reported for sumanene and its derivatives. More interestingly, its application in the absorption of small molecules such as NH3, CO2, CO, and H2 using density functional theory (DFT) calculations has also been revealed [25

Azo-dimethylaminopyridine-functionalized Ni(II)-porphyrin as a photoswitchable nucleophilic catalyst

• Jannis Ludwig,
• Julian Helberg,
• Hendrik Zipse and
• Rainer Herges

Beilstein J. Org. Chem. 2020, 16, 2119–2126, doi:10.3762/bjoc.16.179

• of sugars [6], enzyme mimics [7], and the utilization of intermolecular cooperative effects [8] are further applications of photoswitchable catalysis. Particularly interesting and close to our approach is an early work by Inoue et al. who achieved control of the transformation of CO2 and 1,2

Three new O-isocrotonyl-3-hydroxybutyric acid congeners produced by a sea anemone-derived marine bacterium of the genus Vibrio

• Dandan Li,
• Enjuro Harunari,
• Tao Zhou,
• Naoya Oku and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 1869–1874, doi:10.3762/bjoc.16.154

• culture for 12 h at 37 °C in an atmosphere of 95% air and 5% CO2 saturated with H2O, the drug solutions were transferred into each cell culture to make up 200 μL of the culture. The highest concentration of the vehicle solvents (MeOH or DMSO) was set at 0.5 vol %, where the growth of the cells was not

Polarity effects in 4-fluoro- and 4-(trifluoromethyl)prolines

• Vladimir Kubyshkin

Beilstein J. Org. Chem. 2020, 16, 1837–1852, doi:10.3762/bjoc.16.151

• this weakens their interaction. Similar considerations can be applied to the acidity of the carboxylic group (Figure 6B), where the mutual orientation of the C–X dipole and the carboxylate -CO2− charge has an effect [74]. In diastereomeric fluoroprolines there is a large difference in the mutual

One-pot synthesis of oxazolidinones and five-membered cyclic carbonates from epoxides and chlorosulfonyl isocyanate: theoretical evidence for an asynchronous concerted pathway

• Esra Demir,
• Ozlem Sari,
• Yasin Çetinkaya,
• Ufuk Atmaca,
• Safiye Sağ Erdem and
• Murat Çelik

Beilstein J. Org. Chem. 2020, 16, 1805–1819, doi:10.3762/bjoc.16.148

• oxazolidinones and five-membered cyclic carbonates of various structures. The most well-known strategies for the synthesis of oxazolidinones are the reaction of an amino alcohol with phosgene [5][22], the carbonylation reaction of β-amino alcohols with CO2 or dialkyl carbonates [23][24][25][26][27], the

• multicomponent reaction of rare-earth metal amides [28], the reaction of CO2 with propargylamines or aziridines [29][30] and the cycloaddition reaction of epoxides with isocyanates [31][32]. On the other hand, for the synthesis of five-membered cyclic carbonates, the cycloaddition of CO2 to epoxides, the

Pauson–Khand reaction of fluorinated compounds

• Jorge Escorihuela,
• Daniel M. Sedgwick,
• Alberto Llobat,
• Mercedes Medio-Simón,
• Pablo Barrio and
• Santos Fustero

Beilstein J. Org. Chem. 2020, 16, 1662–1682, doi:10.3762/bjoc.16.138

• , mild oxidizing additives such as amine oxides, aminophosphines, phosphine oxides, and sulfoxides may be used as promoters to facilitate the dissociation step, by oxidatively removing one of the CO ligands in form of CO2 [40]. The most common oxidants are N-morpholine N-oxide (NMO), trimethylamine N

• -workers [46]. In this study, a wide variety of 1,6-enynes bearing fluorine atoms or fluorine-containing groups at the alkenyl or alkynyl positions were synthesized and evaluated as substrates in the intramolecular PKR with dicobalt octacarbonyl [Co2(CO)8] in CH2Cl2 and promoted by NMO. In general, the

• to high yields, except for those bearing marked electron withdrawing groups (Scheme 7). In 2005, Billard and co-workers reported the PKR of α-trifluoromethylated homoallylamine derivatives (Scheme 8) [47]. Both 1,7-enynes 18a and 18b (n = 1) underwent PKR in the presence of 1 equiv of Co2(CO)8 and 10

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

• synthetically controlled to improve the photocatalytic CO2 reduction performance by Zhang and co-workers using plasma treatment [87]. The general process of photocatalysis in metal oxide semiconductors is illustrated in Figure 4 and is as follows: the photoexcitation of an electron across the band gap generates

Activated carbon as catalyst support: precursors, preparation, modification and characterization

• Melanie Iwanow,
• Tobias Gärtner,
• Volker Sieber and
• Burkhard König

Beilstein J. Org. Chem. 2020, 16, 1188–1202, doi:10.3762/bjoc.16.104

• methods from coal precursors. Yang et al. synthesized nitrogen-doped activated carbon from petroleum coke for an enhanced CO2 capture [7]. Pietrzak et al. used high volatile bituminous coals, brown coals and anthracites for modified activated carbon preparation [5][10][11][12]. Lillo-Ródenas et al

• solutions Xu et al. used energy-rich carbon precursors for the spherical carbon preparation via ultrasonic spray pyrolysis. Lithium, sodium or potassium propiolates are one class of such energy rich materials and exhibit leaving groups such as CO, CO2 or C2H2 eliminated by decarbonylation or decarboxylation

• . After preparation of char by carbonization of the precursor materials for a certain time at a defined temperature under inert gas atmosphere, steam, air or CO2 activate the materials at higher temperatures (800–1000 °C) to form a porous structure according to the Equations 1–3 [81][85][86]. It is