Synthetic reactions driven by electron-donor–acceptor (EDA) complexes

• Zhonglie Yang,
• Yutong Liu,
• Kun Cao,
• Xiaobin Zhang,
• Hezhong Jiang and
• Jiahong Li

Beilstein J. Org. Chem. 2021, 17, 771–799, doi:10.3762/bjoc.17.67

• the subsequent reaction (Scheme 28). On account of a wide range of substrates and functional group compatibility, this protocol can be exploited to assemble various β-trifluoromethylated alkynes by three-component reaction without transition-metal catalysis. In 2018, Xu and colleagues [48] proposed

• -protected amines, have been efficiently transformed to suitable pinacol boronic esters. This simple operation without transition-metal catalysis will be widely promoted in the synthesis of important boron-containing molecules in medicine and biology. In 2019, Aggarwal and colleagues [55] proposed that the

• widespread presence in pharmaceutical-, agrochemical-, and materials sciences [73][74][75]. At present, most of the C–N-bonding reactions require transition-metal catalysis, and the reaction conditions are more stringent; however, the EDA-complex pathway proceeds under mild, catalyst-free conditions

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

• [125][126]. 3. Selective depolymerisation of plastics via metal catalysis Research in depolymerisation of plastics by artificial metal catalysts is relatively recent as most of the earliest studies are related to biocatalytic systems. Metal salts are the conventional catalysts for these processes

The preparation and properties of 1,1-difluorocyclopropane derivatives

• Kymbat S. Adekenova,
• Peter B. Wyatt and
• Sergazy M. Adekenov

Beilstein J. Org. Chem. 2021, 17, 245–272, doi:10.3762/bjoc.17.25

• -difluorocyclopropanes in the synthesis of fluoroalkenyl-substituted compounds (monofluoroalkenes) have been actively studied. Great opportunities exist for the use of transition metal catalysis. The catalytic hydrogenolysis of 1,1-difluoro-3-methyl-2-phenylcyclopropane (151) led to the regioselective C2–C3 distal bond

Silver-catalyzed synthesis of β-fluorovinylphosphonates by phosphonofluorination of aromatic alkynes

• Yajing Zhang,
• Qingshan Tian,
• Guozhu Zhang and
• Dayong Zhang

Beilstein J. Org. Chem. 2020, 16, 3086–3092, doi:10.3762/bjoc.16.258

• is the most rapid and convenient one (Scheme 1). Although studies on alkyne difunctionalization are ongoing [23], the successful attachment of a fluorine atom to the resulting alkene through transition metal catalysis remains a challenge. In particular, the phosphonofluorination of alkynes for the

Synthesis of imidazo[1,5-a]pyridines via cyclocondensation of 2-(aminomethyl)pyridines with electrophilically activated nitroalkanes

• Dmitrii A. Aksenov,
• Nikolai A. Arutiunov,
• Vladimir V. Maliuga,
• Alexander V. Aksenov and
• Michael Rubin

Beilstein J. Org. Chem. 2020, 16, 2903–2910, doi:10.3762/bjoc.16.239

• synthesis inhibitor (Figure 1) [10][11][12]. In addition, compounds with this structure were investigated as photoluminescent sensors [13] and have been employed to generate pincer and heterocyclic carbene ligands for transition metal catalysis [14][15]. A lot of efforts have been dedicated to 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

• catalysis and photochemistry. Where transition metal catalysis provides one strategy for C–H bond activation, transition-metal-free photochemical C–H fluorination can provide a complementary selectivity via a radical mechanism that proceeds under milder conditions than thermal radical activation methods

• fluorination methods, of which direct C–H fluorination is among the most powerful. Despite the challenges and limitations associated with the direct fluorination of unactivated C–H bonds, appreciable advancements in manipulating the selectivity and reactivity have been made, especially via transition metal

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

• electrocatalysis, have been achieved recently [53][54][55][56][57][58]. In addition, various transformations merging photoredox catalysis with transition-metal catalysis have been disclosed [59][60][61][62][63][64][65]. Among these different strategies, visible-light photoredox catalysis combined with nickel

• photoreactor emitting UV light at 254 nm, the same reactivity was also reached under visible-light irradiation (blue LEDs), and in the presence of the photosensitizer, Ir(ppy)3. This transformation hence illustrates clearly the potential of combining metal catalysis and photoinduction to design much milder and

Tuneable access to indole, indolone, and cinnoline derivatives from a common 1,4-diketone Michael acceptor

• Dalel El-Marrouki,
• Sabrina Touchet,
• Abderrahmen Abdelli,
• Hédi M’Rabet,
• Mohamed Lotfi Efrit and
• Philippe C. Gros

Beilstein J. Org. Chem. 2020, 16, 1722–1731, doi:10.3762/bjoc.16.144

• [15][16][17][18], nucleophilic and electrophilic cyclizations [19][20][21][22][23][24][25], reductive and oxidative cyclizations [26][27], and transition-metal catalysis [28][29][30][31][32][33][34][35][36][37]. There are fewer ways to access indolone derivatives, mainly based on the use of di- [12

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

Copper-promoted/copper-catalyzed trifluoromethylselenolation reactions

• Clément Ghiazza and
• Anis Tlili

Beilstein J. Org. Chem. 2020, 16, 305–316, doi:10.3762/bjoc.16.30

• they confer very high lipophilicity [1][2]. In this context, transition-metal catalysis plays a key role in the formation of carbon–chalcogen trifluoromethyl bonds. Major advances have been made in the last ten years especially for C–OCF3 [3][4][5] and C–SCF3 [6][7][8] bond-forming processes. Today

Recent developments in photoredox-catalyzed remote ortho and para C–H bond functionalizations

• Rafia Siddiqui and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 248–280, doi:10.3762/bjoc.16.26

• functionalization has been done either using transition metal catalysis or organocatalysis, through the installation of directing groups next to the targeted C–H bond, or by employing radical tactics based on single-electron transfer (SET) [15][16][17][18][19][20][21][22][23][24][25][26][27]. Although

• metal catalysis, which include: (i) excellent regioselectivity of the targeted C–H bond formations thanks to favorable dissociation enthalpies and electronic properties as compared to other concurrent C–H bonds; (ii) avoidance of an extra oxidant because the reaction proceeds with overall redox

• transition metal catalysis. Mechanism for the formation of 21 from 19 using photoredox catalyst 11. Mechanism for the formation of 30 from acetanilide derivatives. Mechanism for the photoredox-catalyzed synthesis of fluorenone derivatives. Plausible mechanism for the construction of benzothiazoles from

AgNTf₂-catalyzed formal [3 + 2] cycloaddition of ynamides with unprotected isoxazol-5-amines: efficient access to functionalized 5-amino-1H-pyrrole-3-carboxamide derivatives

• Ziping Cao,
• Jiekun Zhu,
• Li Liu,
• Yuanling Pang,
• Laijin Tian,
• Xuejun Sun and
• Xin Meng

Beilstein J. Org. Chem. 2019, 15, 2623–2630, doi:10.3762/bjoc.15.255

• . Reactions of ynamides or ynol ethers with isoxazoles by transition metal catalysis. Reactions of ynamide 4a with different isoxazoles 5, 7 and 8a. A gram-scale experiment. Mechanistic hypotheses for Ag-catalyzed reaction of ynamide 4a with aminoisoxazole 8a. Possible reaction routes of intermediate C

Recent advances in transition-metal-catalyzed incorporation of fluorine-containing groups

• Xiaowei Li,
• Xiaolin Shi,
• Xiangqian Li and
• Dayong Shi

Beilstein J. Org. Chem. 2019, 15, 2213–2270, doi:10.3762/bjoc.15.218

• review will provide a comprehensive overview of this topic and attract significant attention. Review Fluorination For many years, specialists in the field of fluorine chemistry have been actively studying ways to introduce fluorine into organic molecules by aid of transition-metal catalysis. Depending on

Attempted synthesis of a meta-metalated calix[4]arene

• Christopher D. Jurisch and
• Gareth E. Arnott

Beilstein J. Org. Chem. 2019, 15, 1996–2002, doi:10.3762/bjoc.15.195

• resulted in applications in several fields, including, amongst others, the use as ligands in transition metal catalysis [2][3], in solid-phase gas sorption [4], as molecular sensors [5][6] and as biomimetic compounds [7][8]. Our own interest has been in the synthesis of inherently chiral calix[4]arenes

Norbornadiene-functionalized triazatriangulenium and trioxatriangulenium platforms

• Roland Löw,
• Talina Rusch,
• Tobias Moje,
• Fynn Röhricht,
• Olaf M. Magnussen and
• Rainer Herges

Beilstein J. Org. Chem. 2019, 15, 1815–1821, doi:10.3762/bjoc.15.175

• the mechanisms of bulk metal catalysis and open new ways to design new catalytic systems. Towards this end, and following the “platform concept”, we designed a cyano-substituted norbornadiene, which is functionalized with an acetylene spacer on a TATA platform to investigate an eventual “spin

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

• development and (ii) for the modifications needed thereof in the R&D sector. Keywords: C–H activation/functionalization; coupling reactions; imidazopyridines; multicomponent reactions; transition metal catalysis; Introduction The structural diversity and biological importance of nitrogen-containing

One-pot activation–alkynylation–cyclization synthesis of 1,5-diacyl-5-hydroxypyrazolines in a consecutive three-component fashion

• Christina Görgen,
• Katharina Boden,
• Guido J. Reiss,
• Walter Frank and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2019, 15, 1360–1370, doi:10.3762/bjoc.15.136

• directed to develop multicomponent syntheses of heterocycles by transition-metal catalysis [41][42] we conceptualized catalytic entries to alkynones and alkynediones as suitable intermediates in addition–cyclocondensation syntheses of numerous heterocycles, which can indeed be prepared by consecutive

Synthesis of dipolar molecular rotors as linkers for metal-organic frameworks

• Sebastian Hamer,
• Fynn Röhricht,
• Marius Jakoby,
• Ian A. Howard,
• Xianghui Zhang,
• Christian Näther and
• Rainer Herges

Beilstein J. Org. Chem. 2019, 15, 1331–1338, doi:10.3762/bjoc.15.132

• Sonogashira reaction [52]. The cross coupling following a Sonogashira protocol was problematic though in our case. Phthalonitrile (1,2-dicyanobenzene) units are known to form phthalocyanines and homologues, especially under harsher reaction conditions, such as the long reaction times and metal catalysis in

New α- and β-cyclodextrin derivatives with cinchona alkaloids used in asymmetric organocatalytic reactions

• Iveta Chena Tichá,
• Simona Hybelbauerová and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2019, 15, 830–839, doi:10.3762/bjoc.15.80

• complexes [2]. CD derivatives have been increasingly applied in catalysis and biomimetic reactions [3][4] thanks to host–guest interactions and to the non-toxic, chiral skeleton of CDs. More specifically, CDs applied in reactions involving metal catalysis [5], organocatalysis [6] and artificial enzymes [7

Thiol-free chemoenzymatic synthesis of β-ketosulfides

• Adrián A. Heredia,
• Martín G. López-Vidal,
• Marcela Kurina-Sanz,
• Fabricio R. Bisogno and
• Alicia B. Peñéñory

Beilstein J. Org. Chem. 2019, 15, 378–387, doi:10.3762/bjoc.15.34

• ][40]. Such a combination has been scarcely exploited as compared to strategies comprising transition metal catalysis and biocatalysis [41] or, in a lesser extent, organocatalysis and enzymes [42]. In this context, a versatile and robust synthesis of β-ketosulfides avoiding the use of thiols under

A novel and efficient synthesis of phenanthrene derivatives via palladium/norbornadiene-catalyzed domino one-pot reaction

• Yue Zhong,
• Wen-Yu Wu,
• Shao-Peng Yu,
• Tian-Yuan Fan,
• Hai-Tao Yu,
• Nian-Guang Li,
• Zhi-Hao Shi,
• Yu-Ping Tang and
• Jin-Ao Duan

Beilstein J. Org. Chem. 2019, 15, 291–298, doi:10.3762/bjoc.15.26

• reaction may cause skin damage to experimenters. Alternatively, alkynes (Scheme 1b) played an important role in the synthesis of phenanthrene scaffolds under transition metal catalysis [9]. However, this protocol required complicated procedures, harsh reaction conditions and was incompatible with many

Synthesis of 1,2-divinylcyclopropanes by metal-catalyzed cyclopropanation of 1,3-dienes with cyclopropenes as vinyl carbene precursors

• Jesús González,
• Alba de la Fuente,
• María J. González,
• Laura Díez de Tejada,
• Luis A. López and
• Rubén Vicente

Beilstein J. Org. Chem. 2019, 15, 285–290, doi:10.3762/bjoc.15.25

• ; transition metal catalysis; Introduction Far from being considered exotic molecules, cyclopropane derivatives constitute an interesting class of compounds. Indeed, far over 4000 natural products bearing a cyclopropane ring have been discovered [1][2][3], and cyclopropane-containing molecules are recurrent

The influence of the cationic carbenes on the initiation kinetics of ruthenium-based metathesis catalysts; a DFT study

• Magdalena Jawiczuk,
• Angelika Janaszkiewicz and
• Bartosz Trzaskowski

Beilstein J. Org. Chem. 2018, 14, 2872–2880, doi:10.3762/bjoc.14.266

• carbene (NHC) by Arduengo [1] was a milestone in organic chemistry which allowed for thorough and systematic studies on all aspects of NHC chemistry in the past 25 years [2][3][4][5][6][7]. It was soon realized that NHCs are a very useful class of ligands for transition metal catalysis as both their

Molecular iodine-catalyzed one-pot multicomponent synthesis of 5-amino-4-(arylselanyl)-1H-pyrazoles

• Camila S. Pires,
• Daniela H. de Oliveira,
• Maria R. B. Pontel,
• Jean C. Kazmierczak,
• Roberta Cargnelutti,
• Diego Alves,
• Raquel G. Jacob and
• Ricardo F. Schumacher

Beilstein J. Org. Chem. 2018, 14, 2789–2798, doi:10.3762/bjoc.14.256

• combine at least two bioactive moieties in one molecule avoiding residual metal in transition-metal catalysis in environmental benign conditions is desired. Recently, Sun and co-workers described their interesting results on the I2-catalyzed efficient synthesis of 5-amino-4-sulfanylpyrazoles using diverse