Recent developments and trends in the iron- and cobalt-catalyzed Sonogashira reactions

• Surendran Amrutha,
• Sankaran Radhika and
• Gopinathan Anilkumar

Beilstein J. Org. Chem. 2022, 18, 262–285, doi:10.3762/bjoc.18.31

• importance of this coupling reaction [7]. Later, Sonogashira-type reactions requiring only copper as catalyst alone [8] and with other transition metals [9][10][11][12] have been reported. Especially iron has attracted a great deal of attention owing to its low price, easy availability, abundant nature, and

• exceptional versatility [13][14][15]. Therefore, the low cost first series transition metals such as iron and cobalt show higher significance than other transition metals. Naturally, Sonogashira cross-coupling reactions using cobalt or iron catalysts were reported as more cost-effective alternatives to the

• organic transformations [16]. The development of improved procedures in which less expensive and more suitable catalysts are used has remained an elusive goal. In this respect, iron catalysts stand out as valuable alternatives to those transition metals used in Sonogashira coupling reactions [17]. With

Iridium-catalyzed hydroacylation reactions of C1-substituted oxabenzonorbornadienes with salicylaldehyde: an experimental and computational study

• Angel Ho,
• Austin Pounder,
• Krish Valluru,
• Leanne D. Chen and
• William Tam

Beilstein J. Org. Chem. 2022, 18, 251–261, doi:10.3762/bjoc.18.30

• mechanism. Although an in-depth investigation into the mechanism of iridium-catalyzed hydroacylation reactions has never been carried out, the mechanistic pathways should parallel those of other analogously reactive d7 metals. On the basis of pioneering mechanistic investigations into rhodium-catalyzed

Diametric calix[6]arene-based phosphine gold(I) cavitands

• Gabriele Giovanardi,
• Andrea Secchi,
• Arturo Arduini and
• Gianpiero Cera

Beilstein J. Org. Chem. 2022, 18, 190–196, doi:10.3762/bjoc.18.21

• , calix[4]- [9][10][11][12][13] and resorcin[4]arene [14][15][16][17] are the most exploited cavitands due to their inherent limited flexibility and already proved their ability to control the catalytic activity of late-transition metals and particularly gold(I) catalysts [18][19][20][21][22][23][24][25

Green synthesis of C5–C6-unsubstituted 1,4-DHP scaffolds using an efficient Ni–chitosan nanocatalyst under ultrasonic conditions

• Soumyadip Basu,
• Sauvik Chatterjee,
• Suman Ray,
• Suvendu Maity,
• Prasanta Ghosh,
• Asim Bhaumik and
• Chhanda Mukhopadhyay

Beilstein J. Org. Chem. 2022, 18, 133–142, doi:10.3762/bjoc.18.14

• delivery [11], biomedical uses [12], removal of toxic metals from wastewater [13], in manufacturing processes [14], in the food industry [15], in agriculture [16], and as catalyst in transesterification reactions [17]. Chitosan is regarded as one of the most effective bio-based polymers to chelate

Earth-abundant 3d transition metals on the rise in catalysis

• Nikolaos Kaplaneris and
• Lutz Ackermann

Beilstein J. Org. Chem. 2022, 18, 86–88, doi:10.3762/bjoc.18.8

• , Germany 10.3762/bjoc.18.8 Keywords: C–H activation; 3d transition metals; green chemistry; late-stage functionalization; sustainability; Transition metal catalysis has emerged as a transformative platform for the assembly of increasingly complex compounds, with enabling applications to natural product

• these indisputable advances, this approach has, thus far, predominantly relied on precious, often toxic, 4d and 5d transition metals, most prominently palladium, rhodium and iridium. In sharp contrast, the use of less expensive and less toxic Earth-abundant 3d transition metals continues to be

• underdeveloped. This lack of viable catalysis strategies involving 3d transition metals is largely due to a limited knowledge on the working mode of these metal catalysts, which often involve single-electron-transfer-based redox events. As a consequence, there is a strong demand for efficient and reliable

Recent advances and perspectives in ruthenium-catalyzed cyanation reactions

• Thaipparambil Aneeja,
• Cheriya Mukkolakkal Abdulla Afsina,
• Padinjare Veetil Saranya and
• Gopinathan Anilkumar

Beilstein J. Org. Chem. 2022, 18, 37–52, doi:10.3762/bjoc.18.4

• demanded the need of an alternative method for the synthesis of nitriles. Nowadays transition-metal-catalyzed reactions have received tremendous interest. Various transition metals such as Fe [15], Co [16], Ni [17], Pd [18], Cu [19], Rh [20] etc. were well explored in cyanation owing to its cost-effective

• of other metals such as Au, Pt, Pd, Rh, Ag, and Fe and found that they were less efficient compared to Ru. The benzylic alcohols showed higher reactivity than aliphatic alcohols towards this methodology. Moreover, this protocol worked well for differently substituted heterocyclic alcohols and

Study on the interactions between melamine-cored Schiff bases with cucurbit[n]urils of different sizes and its application in detecting silver ions

• Jun-Xian Gou,
• Yang Luo,
• Xi-Nan Yang,
• Wei Zhang,
• Ji-Hong Lu,
• Zhu Tao and
• Xin Xiao

Beilstein J. Org. Chem. 2021, 17, 2950–2958, doi:10.3762/bjoc.17.204

• supermolecule polymer with TBT due to its larger cavity. Since Q[7] and TBT form a host–guest complex, the carboxyl group at the end of TBT and the carbonyl group of the Q[7] still have a strong ability to coordinate with metals. Therefore, Q[7]-TBT is selected for the detection of silver ions (Ag+) [32][33

• coordination ability to metals. In this study, Q[7]-TBT was selected as a UV detector to detect common metals. As shown in Figure 5, the additional Ag+ increases the absorbance of the Q[7]-TBT complex from 0.441 to 0.555 at λmax = 258 nm, while other metal ions do not increase or decrease the absorbance

• significantly at this wavelength, so Q[7]-TBT has a higher selectivity to Ag+ among metals. In addition, in the anti-interference experiment, Q[7]-TBT also has a good performance in the detection of silver ions in the presence of other common metals. To further explore the detection limit (DL) and detection

Effect of a twin-emitter design strategy on a previously reported thermally activated delayed fluorescence organic light-emitting diode

• Ettore Crovini,
• Zhen Zhang,
• Yu Kusakabe,
• Yongxia Ren,
• Yoshimasa Wada,
• Bilal A. Naqvi,
• Prakhar Sahay,
• Tomas Matulaitis,
• Stefan Diesing,
• Ifor D. W. Samuel,
• Wolfgang Brütting,
• Katsuaki Suzuki,
• Hironori Kaji,
• Stefan Bräse and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2021, 17, 2894–2905, doi:10.3762/bjoc.17.197

• have elicited tremendous excitement as an alternative to phosphorescent complexes in organic light-emitting diodes (OLEDs) because these organic compounds can also achieve a theoretical 100% internal quantum efficiency (IQE) but do not require the use of scarce, noble metals [1][2]. Since the

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

• products and processes that reduce or eliminate the use and generation of hazardous substances, as well as increase the atom economy of the reaction [9]. Among the transition-metal (TM) catalysts often used, the late transition metals like rhodium [10][11][12][13][14], palladium [15][16][17][18][19

Biological properties and conformational studies of amphiphilic Pd(II) and Ni(II) complexes bearing functionalized aroylaminocarbo-N-thioylpyrrolinate units

• Samet Poyraz,
• Samet Belveren,
• Sabriye Aydınoğlu,
• Mahmut Ulger,
• Abel de Cózar,
• Maria de Gracia Retamosa,
• Jose M. Sansano and
• H. Ali Döndaş

Beilstein J. Org. Chem. 2021, 17, 2812–2821, doi:10.3762/bjoc.17.192

• successfully performed using the corresponding acetate salt in methanol at rt for 48 h, affording cis-L1-M, L2-M, and L3-M in yields depicted in Scheme 1. The relative configuration was unambiguously determined by comparison of their corresponding 1H NMR with the reported similar 1H NMR with other metals, and

Me₃Al-mediated domino nucleophilic addition/intramolecular cyclisation of 2-(2-oxo-2-phenylethyl)benzonitriles with amines; a convenient approach for the synthesis of substituted 1-aminoisoquinolines

• Krishna M. S. Adusumalli,
• Lakshmi N. S. Konidena,
• Hima B. Gandham,
• Krishnaiah Kumari,
• Krishna R. Valluru,
• Satya K. R. Nidasanametla,
• Venkateswara R. Battula and
• Hari K. Namballa

Beilstein J. Org. Chem. 2021, 17, 2765–2772, doi:10.3762/bjoc.17.186

• , they are associated with few limitations including: utilization of metals, transition metals, and difficulties in accessing the starting materials, which provoke the attention of the synthetic community for the development of simple and efficient methodologies towards the construction of these

Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds

• Alemayehu Gashaw Woldegiorgis and
• Xufeng Lin

Beilstein J. Org. Chem. 2021, 17, 2729–2764, doi:10.3762/bjoc.17.185

• (Brønsted acidity/basicity, hydrogen-bonding units, and counter-anions toward metals) [48][49]. In 2019, Shi, Lin, and co-workers achieved an enantioselective synthesis of axially chiral quinoline-derived biaryl atropisomers via Pd-catalyzed C–H olefination of 8-phenylquinoline (11) using a novel chiral

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

• renewable energy and green chemistry for many years. Ruthenium and iridium, which can be used as photoredox catalysts, are expensive and scarce in nature. Thus, the further development of catalysts based on these transition metals is discouraged. Alternative photocatalysts based on copper complexes are

• organic dyes and metal complexes have been investigated [10][11][12]. Photoredox catalysts have been initially applied to organic reactions, but they are now used for complicated organic processes [13]. As photocatalysts, organic dyes have the advantages of having a low price and not containing metals

Copper-catalyzed monoselective C–H amination of ferrocenes with alkylamines

• Zhen-Sheng Jia,
• Qiang Yue,
• Ya Li,
• Xue-Tao Xu,
• Kun Zhang and
• Bing-Feng Shi

Beilstein J. Org. Chem. 2021, 17, 2488–2495, doi:10.3762/bjoc.17.165

• derivatives [13][14][15][16]. Especially, the 3d transition metals, such as Cu, Co and Ni, have been exploited to convert C–H bonds to various functional groups, attributing to the cost-effective and less toxic properties, which render C–H transformations both economically desirable and environmentally benign

• metals. Second, both amines and the resulting aminated products could coordinate with metal catalysts and cause the deactivation of catalysts. Besides, high reaction temperature could lead to a mixture of byproducts or the decomposition of the ferrocene products. Herein, we described a Cu-catalyzed

Advances in mercury(II)-salt-mediated cyclization reactions of unsaturated bonds

• Sumana Mandal,
• Raju D. Chaudhari and
• Goutam Biswas

Beilstein J. Org. Chem. 2021, 17, 2348–2376, doi:10.3762/bjoc.17.153

• transition metal reagents has found considerable applications in organic synthesis [1][2][3][4] and has radically changed the realm of chemical science. It also provides a powerful tool for the construction of complex molecular frameworks [5][6][7]. A plethora of reviews involving transition metals such as

• Hg(OTf)2-catalyzed conditions at lower temperature (Scheme 56) [117]. Following a similar strategy, mercury chlorate (Hg(ClO4)2) had been employed successfully as a cheap alternative to precious metals salts in the cyclization of α-allenol derivatives 185 to differently substituted 2,5-dihydrofurans

Transition-metal-free intramolecular Friedel–Crafts reaction by alkene activation: A method for the synthesis of some novel xanthene derivatives

• Tülay Yıldız,
• İrem Baştaş and
• Hatice Başpınar Küçük

Beilstein J. Org. Chem. 2021, 17, 2203–2208, doi:10.3762/bjoc.17.142

• ]. Therefore, there has been an increase in arylation methods using Friedel–Crafts alkylation (FCA) protocols without transition metals [35][36]. Environmentally friendly methods, in which metal-free catalysts are used, have come to the fore and are gaining importance because there are many disadvantages of

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

• equally effective catalysts. First-row transition (3d) metals have shown to be important catalysts in this matter. This review summarizes the use of 3d metal catalysts in C–H activation processes to obtain potentially (or proved) biologically active compounds. Keywords: bioactive compounds; C–H

• activation; 3d metals; drugs; medicinal chemistry; Introduction The discovery of new biologically active substances represents not only an advance in the chemistry field but also offers innovative chances for pharmacological and biomedical sciences. Every year, several molecules are discovered and studied

• synthetic methodologies is the C–H bond activation process that enables a straightforward access to several important and innovative compounds [14][15][16][17][18]. In the last few years, metals such as ruthenium [19][20][21], rhodium [22][23][24], palladium [25][26][27], and iridium [28][29][30] have been

Development of N-F fluorinating agents and their fluorinations: Historical perspective

• Teruo Umemoto,
• Yuhao Yang and
• Gerald B. Hammond

Beilstein J. Org. Chem. 2021, 17, 1752–1813, doi:10.3762/bjoc.17.123

Sustainable manganese catalysis for late-stage C–H functionalization of bioactive structural motifs

• Jongwoo Son

Beilstein J. Org. Chem. 2021, 17, 1733–1751, doi:10.3762/bjoc.17.122

• powerful synthetic strategy for accessing advanced agrochemicals, bioimaging materials, and drug candidates, among other complex molecules. While traditional late-stage diversification relies on the use of precious transition metals, the utilization of 3d transition metals is an emerging approach in

• organic synthesis. Among the 3d metals, manganese catalysts have gained increasing attention for late-stage diversification due to the sustainability, cost-effectiveness, ease of operation, and reduced toxicity. Herein, we summarize recent manganese-catalyzed late-stage C–H functionalization reactions of

• biologically active small molecules and complex peptides. Keywords: bioactive molecules; 3d transition metals; late-stage functionalization; manganese catalyst; sustainable catalysis; Introduction Manganese, a 3d transition metal, allows for a potentially ideal sustainable catalytic system because of the

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

• expense of the olefin double bond. Review Olefin activation by transition metals Transition metals can act as π-acid catalysts in olefin double bond activation, as they weaken the alkene double bond through coordination to allow a nucleophilic attack on the sp2 carbon to form an alkylmetal intermediate

• nucleophiles, along with transition-metal catalysis, in olefin alkylation reactions [18][19][20][21]. Apart from the early examples of olefin functionalization with transition metals, such as the well-known ethylene oxidation catalyzed by Pd(II) (the Wacker reaction) [23][24], the use of carbon nucleophiles in

• further demonstrated by the hydroalkylation of the anti-inflammatory drug phenylbutazone (7j). Gold(I)/gold(III) and silver(I) catalysis in olefin hydroalkylation The early limitations associated with Pd catalysis in olefin hydroalkylation reactions prompted the search for alternative metals for olefin

One-step synthesis of imidazoles from Asmic (anisylsulfanylmethyl isocyanide)

• Louis G. Mueller,
• Allen Chao,
• Embarek AlWedi and
• Fraser F. Fleming

Beilstein J. Org. Chem. 2021, 17, 1499–1502, doi:10.3762/bjoc.17.106

• etomidate [4] and the antileukemia agent nilotinib [5]. The outstanding and diverse bioactivity of imidazole-containing pharmaceuticals [6], as well as their role as ligands for transition metals [7], and organocatalysis [8], has stimulated an array of creative syntheses [9][10]. Among the numerous routes

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

Heterogeneous photocatalytic cyanomethylarylation of alkenes with acetonitrile: synthesis of diverse nitrogenous heterocyclic compounds

• Guanglong Pan,
• Qian Yang,
• Wentao Wang,
• Yurong Tang and
• Yunfei Cai

Beilstein J. Org. Chem. 2021, 17, 1171–1180, doi:10.3762/bjoc.17.89

• cyanomethylarylation of alkenes, most of them rely on the use of transition metals (such as catalytic amounts of Pd, Cu, Fe catalyst or stoichiometric amounts of Ag, Mn salts) and strong oxidants (including PhI(OPiv)2, DTBP, and t-BuONO) in the presence of various base additives under high reaction temperatures or

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

• allylic bromides in the presence of zinc or indium metals is a well-known reaction [66][67]. It is possible to control and predict the stereochemistry of the addition to get the corresponding homoallylamine derivative with a high level of stereocontrol. The reaction of chiral imine 14 with an excess of

Synthetic accesses to biguanide compounds

• Oleksandr Grytsai,
• Cyril Ronco and
• Rachid Benhida

Beilstein J. Org. Chem. 2021, 17, 1001–1040, doi:10.3762/bjoc.17.82

• satisfying 57% yield (Scheme 31A) [68]. Furthermore, the formation of this byproduct was particularly promoted in the case of hindered amines such as diisopropylamine and dicyclohexylamine. Recently, to study the complexation properties of N-amidino-amidinopyrazole with transition metals, its synthesis was