A novel and robust heterogeneous Cu catalyst using modified lignosulfonate as support for the synthesis of nitrogen-containing heterocycles

• Bingbing Lai,
• Meng Ye,
• Ping Liu,
• Minghao Li,
• Rongxian Bai and
• Yanlong Gu

Beilstein J. Org. Chem. 2020, 16, 2888–2902, doi:10.3762/bjoc.16.238

• the catalyst during the recovery process (mass recovery 97.5%). In stark contrast, the two referential catalysts showed inferior recyclability (Figure 6b and 6c) not only because the mass loss but also the low stability and capacity of the metals. Conclusion A robust heterogeneous Cu catalyst was

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

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

A proposed sustainability index for synthesis plans based on input provenance and output fate: application to academic and industrial synthesis plans for vanillin as a case study

• John Andraos

Beilstein J. Org. Chem. 2020, 16, 2346–2362, doi:10.3762/bjoc.16.196

• converse rate condition is true. Specifically, inputs derived from renewable or recycled sources such as biomass, scrap metals, or retrieved byproducts from other processes are considered valorized, and inputs derived from non-renewable sources such as fossil fuels and virgin mineral ores are considered

• control of prices of crude oil, natural gas, and metals; whereas, disclosing accurate and up-to-date information can expose vulnerabilities among governments and investors that can be taken advantage of. Furthermore, deciding where to terminate a chain of resources, i.e., which material to designate as

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

• of the vital modes in metal binding and a range of π-conjugated planar systems having ηn-binding to metals have been reported. In contrast, buckybowls have multiple coordination sites for instance the positions available in the polycyclic architecture and also because of the presence of concave or

• convex faces. Therefore, in recent years, the coordination of bowl-shaped molecules with the transition metals is of fundamental interest in the area of π-bowls chemistry since the first details of the metal complex of C60. In this context, Hirao’s group has reported the first example of Fe(η6-sumanene

Regioselective cobalt(II)-catalyzed [2 + 3] cycloaddition reaction of fluoroalkylated alkynes with 2-formylphenylboronic acids: easy access to 2-fluoroalkylated indenols

• Tatsuya Kumon,
• Miroku Shimada,
• Jianyan Wu,
• Shigeyuki Yamada and
• Tsutomu Konno

Beilstein J. Org. Chem. 2020, 16, 2193–2200, doi:10.3762/bjoc.16.184

• the most efficient and convenient protocols for the construction of various 2,3-disubstituted indene derivatives, such as indenols and indenamines (Scheme 1b) [23][24][25]. There have been numerous studies on the reaction with nonfluorinated alkynes under the influence of various transition metals

Efficient [(NHC)Au(NTf₂)]-catalyzed hydrohydrazidation of terminal and internal alkynes

• Maximillian Heidrich and
• Herbert Plenio

Beilstein J. Org. Chem. 2020, 16, 2080–2086, doi:10.3762/bjoc.16.175

• oxygen and nitrogen-containing molecules, which tend to be more difficult for catalytic transformations utilizing other transition metals [32][33][34][35][36]. The [LAu(NTf2)]-catalyzed reaction can be described by a general mechanism (Scheme 1), in which the coordination of LAu+ by the alkyne [37][38

Syntheses of spliceostatins and thailanstatins: a review

• William A. Donaldson

Beilstein J. Org. Chem. 2020, 16, 1991–2006, doi:10.3762/bjoc.16.166

• endpoint. However, Nicolaou’s route is the shortest (6 or 7 steps, 9.8–9.2% yield), while Kitahara’s synthesis is the highest-yielding and does not involve the use of expensive transition metals or organocatalysts. Syntheses to generate the C-14 stereocenter via C–N bond formation Two groups implemented

Metal-free synthesis of phosphinoylchroman-4-ones via a radical phosphinoylation–cyclization cascade mediated by K₂S₂O₈

• Qiang Liu,
• Weibang Lu,
• Guanqun Xie and
• Xiaoxia Wang

Beilstein J. Org. Chem. 2020, 16, 1974–1982, doi:10.3762/bjoc.16.164

• well-known for their medicinal, biological, or specific material-related properties and have found wide applications in pharmaceutical chemistry, biochemistry, and materials science [21][22][23][24][25][26]. They represent also excellent ligands for many metals and have been used in catalytic systems

Synergy between supported ionic liquid-like phases and immobilized palladium N-heterocyclic carbene–phosphine complexes for the Negishi reaction under flow conditions

• Edgar Peris,
• Raúl Porcar,
• María Macia,
• Jesús Alcázar,
• Eduardo García-Verdugo and
• Santiago V. Luis

Beilstein J. Org. Chem. 2020, 16, 1924–1935, doi:10.3762/bjoc.16.159

• cross-coupling; NHC complex; palladium; supported ionic liquid; Introduction N-heterocyclic carbenes (NHCs) are known as efficient coordination ligands for different types of metals. The main feature of NHC complexes is their structural tunability [1]. Thus, their catalytic efficiency can be easily

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 the 21st century there is a real renaissance for photocatalysis, with great advances achieved mainly in visible-light-mediated reactions [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43]. Various photosensitizers, initially based on noble metals (such as Ir and Ru polypyridine complexes

• functionalization have focused major attention of the scientific community [13][22]. However, these transformations frequently required noble metals, such as Pd, Rh and Ru, and rather harsh reaction conditions. In 2016, Ackermann reported a clear advance towards more sustainable and milder C–H functionalization of

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

• described, including the use of metals other than cobalt (such as rhodium, iridium, titanium, ruthenium, nickel, and palladium), or the use of CO surrogates such as aldehydes, alcohols and formates. Recently, its utility in flow chemistry has also been described [42]. Intramolecular Pauson–Khand reactions

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

• size distribution of the deposited nanoparticles [158]. Colmenares and co-workers have reported these methodologies for the synthesis of TiO2 HPCats doped with various transition metals, such as Fe, Pd, Pt, and Au [159][160][161]. For more information, we recommend a recent review published by

Synthesis of new fluorescent molecules having an aggregation-induced emission property derived from 4-fluoroisoxazoles

• Kazuyuki Sato,
• Akira Kawasaki,
• Yukiko Karuo,
• Atsushi Tarui,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2020, 16, 1411–1417, doi:10.3762/bjoc.16.117

• diketone (Scheme 5). As an alternative method to synthesize F-BKIs 9, we turned our attention to the ring-opening reaction of isoxazoles. The reductive cleavage of the N–O bond in isoxazoles can be achieved by transition metals or their complexes to give the corresponding enaminoketones [35][37

Disposable cartridge concept for the on-demand synthesis of turbo Grignards, Knochel–Hauser amides, and magnesium alkoxides

• Mateo Berton,
• Kevin Sheehan,
• Andrea Adamo and
• D. Tyler McQuade

Beilstein J. Org. Chem. 2020, 16, 1343–1356, doi:10.3762/bjoc.16.115

• chemistry technologies and cartridges containing activated metals can solve most of these issues: (1) the use of activated magnesium powder packed in a column increases the reaction rate and facilitates safe separation of the metal and reagent solution; (2) an efficient heat transfer (a large surface area

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

• states with different classes of molecules. However, the relatively high cost of these photocatalysts, their toxicity, and the limited abundance of the coordinating transition metals can hamper their applicability [13]. For these reasons, the quest for cheaper, more sustainable, and environmentally

Development of fluorinated benzils and bisbenzils as room-temperature phosphorescent molecules

• Shigeyuki Yamada,
• Takuya Higashida,
• Yizhou Wang,
• Masato Morita,
• Takuya Hosokai,
• Kaveendra Maduwantha,
• Kaveenga Rasika Koswattage and
• Tsutomu Konno

Beilstein J. Org. Chem. 2020, 16, 1154–1162, doi:10.3762/bjoc.16.102

• (e.g., Ru [14], Ir [15][16], Pt [17], and Au [18][19][20][21]) (Figure 1A), and this offers a molecular design approach for phosphorescence emission. However, it is becoming necessary to explore alternatives to rare metals because of the latter’s scarcity and toxicity. Owing to recent considerable

The charge-assisted hydrogen-bonded organic framework (CAHOF) self-assembled from the conjugated acid of tetrakis(4-aminophenyl)methane and 2,6-naphthalenedisulfonate as a new class of recyclable Brønsted acid catalysts

• Svetlana A. Kuznetsova,
• Alexander S. Gak,
• Yulia V. Nelyubina,
• Vladimir A. Larionov,
• Han Li,
• Michael North,
• Vladimir P. Zhereb,
• Alexander F. Smol'yakov,
• Artem O. Dmitrienko,
• Michael G. Medvedev,
• Igor S. Gerasimov,
• Ashot S. Saghyan and
• Yuri N. Belokon

Beilstein J. Org. Chem. 2020, 16, 1124–1134, doi:10.3762/bjoc.16.99

• , 117198 Moscow, Russian Federation Green Chemistry Centre of Excellence, Department of Chemistry, University of York, Heslington, YO10 5DD, United Kingdom Siberian Federal University, School of Non-Ferrous Metals and Material Science, 95 Krasnoyarskiy Rabochiy pr., 660025 Krasnoyarsk, Russian Federation N

Accelerating fragment-based library generation by coupling high-performance photoreactors with benchtop analysis

• Quentin Lefebvre,
• Christophe Salomé and
• Thomas C. Fessard

Beilstein J. Org. Chem. 2020, 16, 982–988, doi:10.3762/bjoc.16.87

• -catalyzed cross-coupling reactions [9]. Recently, milder cross-coupling methods using more abundant and affordable metals such as nickel, in combination with photochemistry or electrochemistry, significantly improved accessibility to N-arylated complex amines [10][11][12]. Results and Discussion As we

Synthesis and properties of tetrathiafulvalenes bearing 6-aryl-1,4-dithiafulvenes

• Aya Yoshimura,
• Hitoshi Kimura,
• Kohei Kagawa,
• Mayuka Yoshioka,
• Toshiki Itou,
• Dhananjayan Vasu,
• Takashi Shirahata,
• Hideki Yorimitsu and
• Yohji Misaki

Beilstein J. Org. Chem. 2020, 16, 974–981, doi:10.3762/bjoc.16.86

• ion complexes with DDQ or iodine were reported [17][18][19][20][21][22][23][24]. Peripherally thiophene-functionalized TTFs, as potential precursors to conducting polymers, and organic metals were also prepared and characterized [25][26][27][28][29]. To design more tempting molecules, the attachment

Pd-catalyzed asymmetric Suzuki–Miyaura coupling reactions for the synthesis of chiral biaryl compounds with a large steric substituent at the 2-position

• Yongsu Li,
• Bendu Pan,
• Xuefeng He,
• Wang Xia,
• Yaqi Zhang,
• Hao Liang,
• Chitreddy V. Subba Reddy,
• Rihui Cao and
• Liqin Qiu

Beilstein J. Org. Chem. 2020, 16, 966–973, doi:10.3762/bjoc.16.85

• from chemists because of their widespread appearance in biologically active compounds [1][2][3][4] such as vancomycin [5] and korupensamine A [6] and as useful chiral ligands in asymmetric catalysis. Different strategies with various metals and phosphine ligands had been successfully employed for the

Recent applications of porphyrins as photocatalysts in organic synthesis: batch and continuous flow approaches

• Rodrigo Costa e Silva,
• Luely Oliveira da Silva,
• Aloisio de Andrade Bartolomeu,
• Timothy John Brocksom and
• Kleber Thiago de Oliveira

Beilstein J. Org. Chem. 2020, 16, 917–955, doi:10.3762/bjoc.16.83

• obtained by photooxidation of benzaldehydes using Pt porphyrin (Pt-TMP) [49] and Pd porphyrin (2Pd) [50] (Scheme 23). Overall, the fine-tuning of the electrochemical potential of metals and porphyrins enables the oxidation of alcohols to aldehydes or aldehydes to carboxylic acids in a very controlled and

Copper catalysis with redox-active ligands

• Agnideep Das,
• Yufeng Ren,
• Cheriehan Hessin and
• Marine Desage-El Murr

Beilstein J. Org. Chem. 2020, 16, 858–870, doi:10.3762/bjoc.16.77

• -abundant metals, such as copper, with radical ligands is originally known from biological systems such as metalloenzymes [1]. Among the myriad of existing enzymes, galactose oxidase (GAO) is a copper-based enzyme performing the two-electron oxidation of galactose through a mechanism involving the metal and

• phenols, ketones and 1,3-dienes (Scheme 6) [27]. C–C bond formation Complexes of radical and redox-active ligands with transition metals are known to be able to promote radical reactions through single-electron transfer (SET) processes [28]. Expanding on the research area pioneered by Wieghardt and

• scaffolds such as gem-disubstituted (21k) and trisubstituted (21i and 21n,o) aziridines (Scheme 11). Furthermore, the reaction conditions are compatible with aldehyde, ester or ketone functions. Metalloenzymes routinely rely on 3d metals and amino acid-derived coordination spheres to perform complex (multi

Aldehydes as powerful initiators for photochemical transformations

• Maria A. Theodoropoulou,
• Nikolaos F. Nikitas and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2020, 16, 833–857, doi:10.3762/bjoc.16.76

• , having multiple advantages since ligand manipulation can lead to optimized photoredox properties. Unfortunately, the use of metals can pose some critical disadvantages in an organic process. Especially since the natural abundance of various noble metals that are used as photocatalysts is limited and

Recent advances in photocatalyzed reactions using well-defined copper(I) complexes

• Mingbing Zhong,
• Xavier Pannecoucke,
• Philippe Jubault and
• Thomas Poisson

Beilstein J. Org. Chem. 2020, 16, 451–481, doi:10.3762/bjoc.16.42

• organic chemistry. Despite the impressive advances reported since the renewal of the field in 2008 [2][3][4], several issues still have to be addressed. Indeed, most of the developed reactions relied on the use of organometallic complexes of expensive noble metals, such as iridium and ruthenium [5]. Even

• though their efficiency is outstanding, their use for industrial purposes might be hampered. Indeed, the limited availability of these metals and their prices often prohibit the development of economically efficient chemical processes [6]. In addition, the depletion of natural resources raises questions

• about the future availability of these metals at a reasonable cost. With regards to organic dyes, impressive developments have been achieved, but these catalysts might suffer from a low photochemical stability, and thus hampering their use and recyclability [7]. Therefore, alternative solutions have to