Palladium nanoparticles supported on chitin-based nanomaterials as heterogeneous catalysts for the Heck coupling reaction

• Tony Jin,
• Malickah Hicks,
• Davis Kurdyla,
• Sabahudin Hrapovic,
• Edmond Lam and
• Audrey Moores

Beilstein J. Org. Chem. 2020, 16, 2477–2483, doi:10.3762/bjoc.16.201

• ], environmental remediation [5], and catalysis [6]. With their high solubility and presence of functionalities such as hydroxy groups, sulfate half-esters, and carboxylates, CNCs are able to stabilize highly disperse metal nanoparticles (NPs), which can act as heterogeneous catalysts for a wide array of organic

• transformations [7][8][9]. Furthermore, the chiral nature of polysaccharides has also been used as a tool for enantioselective catalysis such as carbonyl hydrogenations and amino acid hydrolysis, proving the unique ability of these biomass-based supports [10][11]. Chitin is another type of biomass feedstock that

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

• for inducing different organic transformations under extremely mild conditions without threatening reagents and conditions [83][84][85]. There are three commonly observed and distinct mechanisms of photocatalytic activation [86] in the context of organic synthesis: i) Most reported photocatalytic

Natural dolomitic limestone-catalyzed synthesis of benzimidazoles, dihydropyrimidinones, and highly substituted pyridines under ultrasound irradiation

• Kumar Godugu,
• Venkata Divya Sri Yadala,
• Mohammad Khaja Mohinuddin Pinjari,
• Trivikram Reddy Gundala,
• Lakshmi Reddy Sanapareddy and
• Chinna Gangi Reddy Nallagondu

Beilstein J. Org. Chem. 2020, 16, 1881–1900, doi:10.3762/bjoc.16.156

• . Further, dolomite is used as a heterogeneous green catalyst in very few organic transformations, such as Knoevenagel, Michael–Henry, and transesterification reactions [73][74]. To the best of our knowledge, there are no reports on the NDL-catalyzed synthesis of aforesaid N-heterocycles under ultrasonic

Et₃N/DMSO-supported one-pot synthesis of highly fluorescent β-carboline-linked benzothiophenones via sulfur insertion and estimation of the photophysical properties

• Dharmender Singh,
• Vipin Kumar and
• Virender Singh

Beilstein J. Org. Chem. 2020, 16, 1740–1753, doi:10.3762/bjoc.16.146

• functional groups and aza-heterocyclic frameworks. However, organic transformations in which aromatic nitro groups act as leaving groups are less reported and require the use of transition-metal catalysts such as Cu, Rh, Pd, etc. [35][36][37]. Though, several elegant methods have been developed for the

Azidophosphonium salt-directed chemoselective synthesis of (E)/(Z)-cinnamyl-1H-triazoles and regiospecific access to bromomethylcoumarins from Morita–Baylis–Hillman adducts

• Soundararajan Karthikeyan,
• Radha Krishnan Shobana,
• Kamarajapurathu Raju Subimol,
• J. Helen Ratna Monica and
• Ayyanoth Karthik Krishna Kumar

Beilstein J. Org. Chem. 2020, 16, 1579–1587, doi:10.3762/bjoc.16.130

• developing a one-pot synthetic strategy will be worthwhile for pharmacologically important triazoles, such as isavuconazole, tazobactam, and ravuconazole [35]. Results and Discussion Initially, phosphonium salts were barely utilised or exploited in synthetic transformations. Later, in 2014, several organic

• transformations employed quaternary phosphonium salts as favourable catalysts [36]. Their synthetic utility was not only confined to catalysis, but they were also used as intermediates for the synthesis of 1H-indazoles [37], as promoters for stereoselective rearrangements [38], and as temporary protectors of O,P

Distinctive reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines under photoredox conditions

• Shrikant D. Tambe,
• Kwan Hong Min,
• Naeem Iqbal and
• Eun Jin Cho

Beilstein J. Org. Chem. 2020, 16, 1335–1342, doi:10.3762/bjoc.16.114

• substituted (E)-N-benzylidene-[1,1'-biphenyl]-2-amines were studied in CH3OH (Scheme 3) [51][52][53][54][55][56]. It is noteworthy that the resulting symmetrical 1,2-diamine compounds are potential ligands for a variety of organic transformations. The dimerization reactions proceeded well, regardless of 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

• (Scheme 26) [61][67][68]. In this section, both reactions are presented and discussed. Singlet oxygen in pericyclic reactions Many important organic transformations can be performed by singlet oxygen including ene, [2 + 2] and [4 + 2] cycloaddition reactions for the formation of hydroperoxides, dioxetanes

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

• Maria A. Theodoropoulou Nikolaos F. Nikitas Christoforos G. Kokotos Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Athens 15784, Greece 10.3762/bjoc.16.76 Abstract Photochemistry, the use of light to promote organic transformations, has

Combining enyne metathesis with long-established organic transformations: a powerful strategy for the sustainable synthesis of bioactive molecules

• Valerian Dragutan,
• Ileana Dragutan,
• Albert Demonceau and
• Lionel Delaude

Beilstein J. Org. Chem. 2020, 16, 738–755, doi:10.3762/bjoc.16.68

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

• in this vital area of research, to our best knowledge, this is the first review that focuses on ortho and para C–H functionalizations by photoredox catalysis to provide atom- and step-economic organic transformations. We are certain that this review will act as a promoter to highlight the application

A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions

• Munmun Ghosh,
• Valmik S. Shinde and
• Magnus Rueping

Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264

• Munmun Ghosh Valmik S. Shinde Magnus Rueping KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia 10.3762/bjoc.15.264 Abstract The direct exploitation of ‘electrons’ as reagents in synthetic organic transformations is on the verge of a

• sequences, these strategies enable advancements in reaction scalability as well as tunability. Having described the research that has been conducted to achieve suitable ‘electrical’ replacements of conventional ‘chemical’ organic transformations, it is clear that the establishment of stereoselective

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

• a prevalent catalyst in a huge number of organic transformations. Similar to palladium complexes, copper complexes generally exist in four oxidation states, Cu(0), Cu(I), Cu(II), and Cu(III) and various fluorination reactions could be developed by different catalytic mechanisms. Fluorination of

Naphthalene diimides with improved solubility for visible light photoredox catalysis

• Barbara Reiß and
• Hans-Achim Wagenknecht

Beilstein J. Org. Chem. 2019, 15, 2043–2051, doi:10.3762/bjoc.15.201

• conclusively showed that there is no universal photoredox catalyst for different organic transformations. Instead, each photoredox catalyst has its own reactivity profile and scope. In order to apply organic dyes in advanced photoredox catalysts in a versatile way, it is crucial that modifications can be

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

• (Scheme 8). Heterogenization of organic catalysts on Fe3O4 NPs has attracted much attention as these catalysts can be recovered by an external magnetic field and reused in subsequent reactions. Some metal complexes of 2,2-biimidazole (H2Biim) found to be effective catalysts in many organic transformations

• the use of toxic reagents and solvents, harsh reaction conditions and long reaction times. The use of a heterogeneous catalyst and water made this method a green and sustainable approach for organic transformations. This transformation involved the well known three-component reaction of 3 with 1 and 2

• copper catalyst dissolved in ionic liquid to four synthetic cycles. Nanotechnology coupled with heterogeneous catalysis has emerged as an efficient field of catalysis for various organic transformations. Inspired from this Bagdi et al. have reported a nano-copper oxide-mediated three-component A3

A heteroditopic macrocycle as organocatalytic nanoreactor for pyrroloacridinone synthesis in water

• Piyali Sarkar,
• Sayan Sarkar and
• Pradyut Ghosh

Beilstein J. Org. Chem. 2019, 15, 1505–1514, doi:10.3762/bjoc.15.152

• summary, a multifunctional heteroditopic macrocycle is established as an efficient nanoreactor for organic transformations in water. Using this macrocycle, a library of biologically interesting highly substituted pyrroloacridines has been synthesized with high yields from easily available starting

• aggregation tendency. Herein we have extensively explored a multifunctional macrocycle (BATA-MC), comprising bis-amide and tris-amine functionalities as H-bond donor/acceptor moieties, and parallel benzene moieties for aromatic π–π stacking interactions as an organocatalytic nanoreactor for organic

• transformations, in particular, for the synthesis of biologically important highly substituted pyrroloacridines in the ecofriendly solvent water. Results and Discussion Synthesis of the macrocycle Considerable efforts in synthesizing multifunctional macrocycles have been dedicated lately for the construction of

Mechanochemistry of supramolecules

• Anima Bose and
• Prasenjit Mal

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

• practiced in supramolecular chemistry to produce complex molecules with topological diversity [81]. Therefore, organic transformations through subcomponent synthesis under mechano-milling conditions might be considered as a useful tool for performing a chemical reaction in a greener fashion. The

Oxidative radical ring-opening/cyclization of cyclopropane derivatives

• Yu Liu,
• Qiao-Lin Wang,
• Zan Chen,
• Cong-Shan Zhou,
• Bi-Quan Xiong,
• Pan-Liang Zhang,
• Chang-An Yang and
• Quan Zhou

Beilstein J. Org. Chem. 2019, 15, 256–278, doi:10.3762/bjoc.15.23

• several decades [39][40][41][42]. The free radical reaction was applied in a range of organic transformations because of its unique advantages such as excellent reactivity, mild conditions, functional group tolerance, and atom economy. A series of radicals, such as carbon, Se, CF3, halogen, S and N

Copolymerization of epoxides with cyclic anhydrides catalyzed by dinuclear cobalt complexes

• Yo Hiranoi and
• Koji Nakano

Beilstein J. Org. Chem. 2018, 14, 2779–2788, doi:10.3762/bjoc.14.255

• methods [22][23][24][25][26]. Cooperative dinuclear metal catalysts have been considered as a promising design for high activity and/or selectivity in organic transformations including polymerizations [27][28][29][30]. This was found to be true for the epoxide/CA copolymerization. In 2013, Lu and co

An overview on recent advances in the synthesis of sulfonated organic materials, sulfonated silica materials, and sulfonated carbon materials and their catalytic applications in chemical processes

• Hashem Sharghi,
• Pezhman Shiri and
• Mahdi Aberi

Beilstein J. Org. Chem. 2018, 14, 2745–2770, doi:10.3762/bjoc.14.253

• handling, and even reusability [34]. Ionic liquids (ILs) have been extensively reported as green solvents in organic transformations, owing to their considerable properties such as the ability to dissolve a wide range of substances, very low vapor pressure, high thermal stability, recyclability, non

Learning from B₁₂ enzymes: biomimetic and bioinspired catalysts for eco-friendly organic synthesis

• Keishiro Tahara,
• Ling Pan,
• Toshikazu Ono and
• Yoshio Hisaeda

Beilstein J. Org. Chem. 2018, 14, 2553–2567, doi:10.3762/bjoc.14.232

• reductases to B12 was replaced with that from the cathodes to B12 derivatives [43]. Light-driven organic transformations attract great attention due to their relevance to photosynthesis in nature as an ideal sustainable system [92][93][94]. In this context, we constructed light-driven catalytic systems using

Catalyst-free synthesis of 4-acyl-NH-1,2,3-triazoles by water-mediated cycloaddition reactions of enaminones and tosyl azide

• Lu Yang,
• Yuwei Wu,
• Yiming Yang,
• Chengping Wen and
• Jie-Ping Wan

Beilstein J. Org. Chem. 2018, 14, 2348–2353, doi:10.3762/bjoc.14.210

• adventure in enaminone-based organic transformations has led us to the discovery that the cycloaddition of N,N-dimethylenaminones and tosyl azide efficiently affords NH-1,2,3-triazoles with water as the only medium, and not any catalyst or additive is required. Considering the featured functions of NH-1,2,3

Hydroarylations by cobalt-catalyzed C–H activation

• Rajagopal Santhoshkumar and
• Chien-Hong Cheng

Beilstein J. Org. Chem. 2018, 14, 2266–2288, doi:10.3762/bjoc.14.202

• Rajagopal Santhoshkumar Chien-Hong Cheng Department of Chemistry, National Tsing Hua University, Taiwan 10.3762/bjoc.14.202 Abstract As an earth-abundant first-row transition metal, cobalt catalysts offer a broad range of economical methods for organic transformations via C–H activation. One of

Cobalt-catalyzed C–H cyanations: Insights into the reaction mechanism and the role of London dispersion

• Eric Detmar,
• Valentin Müller,
• Daniel Zell,
• Lutz Ackermann and
• Martin Breugst

Beilstein J. Org. Chem. 2018, 14, 1537–1545, doi:10.3762/bjoc.14.130

• – the attractive part of the van-der-Waals interaction – is known for more than 100 years [1][2]. The stabilizing nature of C–H···H–C interactions and their importance for organic transformations has only been fully realized within the last decades [3]. Among others, these interactions explain the

A survey of chiral hypervalent iodine reagents in asymmetric synthesis

• Soumen Ghosh,
• Suman Pradhan and
• Indranil Chatterjee

Beilstein J. Org. Chem. 2018, 14, 1244–1262, doi:10.3762/bjoc.14.107

• of an external oxidant. The use of catalytic chiral hypervalent iodine reagents in asymmetric catalysis is one of the most challenging ongoing topics and this review will focus on the development of various chiral hypervalent iodine reagents and their application in typical organic transformations

• substantial growth in the field of chiral hypervalent iodine reagents. This review points a number of striking chiral hypervalent iodine reagents used in stoichiometric or in catalytic fashion for quite a number of useful organic transformations. Most importantly the oxidative chemistry can be done using

Sequential Ugi reaction/base-induced ring closing/IAAC protocol toward triazolobenzodiazepine-fused diketopiperazines and hydantoins

• Robby Vroemans,
• Fante Bamba,
• Jonas Winters,
• Joice Thomas,
• Jeroen Jacobs,
• Luc Van Meervelt,
• Jubi John and
• Wim Dehaen

Beilstein J. Org. Chem. 2018, 14, 626–633, doi:10.3762/bjoc.14.49

• accessed by designing sequential organic transformations incorporating multicomponent reactions [1][2] combined with secondary transformations [3][4][5][6][7][8][9][10][11]. Over the past decade, several groups of chemists interested in synthetic chemistry have efficiently utilized the strategy of linking