A method to determine the correct photocatalyst concentration for photooxidation reactions conducted in continuous flow reactors

• Clemens R. Horn and
• Sylvain Gremetz

Beilstein J. Org. Chem. 2020, 16, 871–879, doi:10.3762/bjoc.16.78

• the combination of light, the “greenest reagent” oxygen, and a catalyst as well as applying mild process conditions under process-intensified conditions can be considered a very sustainable setup [12][13][14]. The scaling-up of photoflow reactors has also been affected by the increased use of LED

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

• presented. Keywords: aldehyde; green chemistry; photochemistry; photoinitiation; sustainable chemistry; Introduction Photochemistry, and especially photoredox catalysis have altered the way that modern researchers treat radical species [1][2][3][4]. In most cases, a metal-based photocatalyst is employed

• seek greener and sustainable processes to advance chemistry, the use of aldehydes in conjunction with light irradiation, even sunlight, will become more popular, providing a vast array of applications. Norrish type I and II dissociations. Proposed radical pair formation after the photolysis of

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

• potential of enyne metathesis in providing sustainable access to bioactive organic compounds, when used in conjunction with a number of name reactions. Enyne metathesis is a fundamental chemical transformation involving an alkene and an alkyne to produce a dienic structure through unsaturated bond

Recent advances in Cu-catalyzed C(sp³)–Si and C(sp³)–B bond formation

• Balaram S. Takale,
• Ruchita R. Thakore,
• Elham Etemadi-Davan and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2020, 16, 691–737, doi:10.3762/bjoc.16.67

• at cryogenic temperatures, hence, they are neither economical nor sustainable [71][72][73]. Alternatively, the Kobayashi [74] group has shown that such reactions can be done not only more efficiently, but in a far “greener” fashion using water as the solvent, catalytic amounts of copper, and the

Aerobic synthesis of N-sulfonylamidines mediated by N-heterocyclic carbene copper(I) catalysts

• Faïma Lazreg,
• Marie Vasseur,
• Alexandra M. Z. Slawin and
• Catherine S. J. Cazin

Beilstein J. Org. Chem. 2020, 16, 482–491, doi:10.3762/bjoc.16.43

• Faima Lazreg Marie Vasseur Alexandra M. Z. Slawin Catherine S. J. Cazin School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK Centre for Sustainable Chemistry and Department of Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Ghent, Belgium 10.3762/bjoc.16.43 Abstract A new

Photophysics and photochemistry of NIR absorbers derived from cyanines: key to new technologies based on chemistry 4.0

• Bernd Strehmel,
• Christian Schmitz,
• Ceren Kütahya,
• Yulian Pang,
• Anke Drewitz and
• Heinz Mustroph

Beilstein J. Org. Chem. 2020, 16, 415–444, doi:10.3762/bjoc.16.40

Visible-light-induced addition of carboxymethanide to styrene from monochloroacetic acid

• Kaj M. van Vliet,
• Nicole S. van Leeuwen,
• Albert M. Brouwer and
• Bas de Bruin

Beilstein J. Org. Chem. 2020, 16, 398–408, doi:10.3762/bjoc.16.38

• discussions regarding the IR spectroscopy measurements. Funding This research was supported by The Netherlands Organization for Scientific Research (NWO), the Holland Research School of Molecular Chemistry (HRSMC), the UvA Research Priority Area “Sustainable Chemistry” and the Advanced Research Center

Oligomeric ricinoleic acid preparation promoted by an efficient and recoverable Brønsted acidic ionic liquid

• Fei You,
• Xing He,
• Song Gao,
• Hong-Ru Li and
• Liang-Nian He

Beilstein J. Org. Chem. 2020, 16, 351–361, doi:10.3762/bjoc.16.34

• sustainable synthesis protocol is urgently needed to make the product really green. In this work, an environment-friendly Brønsted acidic ionic liquid (IL) 1-butanesulfonic acid diazabicyclo[5.4.0]undec-7-ene dihydrogen phosphate ([HSO3-BDBU]H2PO4) was developed as the efficient catalyst for the production of

• liquids; oligomeric ricinoleic acid; ricinoleic acid; sustainable catalysis; Introduction In recent years, the biomass has attracted much attention due to its abundance, renewability and potential of conversion to useful chemicals. It can’t be denied that the diverse transformation and utilization of

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

• groundbreaking advancements were accomplished in this wonderful area of research, transforming a specific C–H bond effectively and selectively under favorable conditions (viz, room temperature, without external oxidant, cost-effective, sustainable, and environmentally friendly) still remains a highly challenging

• a more sustainable procedure [88] in comparison to previously reported methods [89][90][91][92]. These semiconductor photocatalysts were better because they were: (i) cheap, (ii) easily separable from the reaction mixture, (iii) compatible with other transition metals, and (iv) provided steady

Understanding the role of active site residues in CotB2 catalysis using a cluster model

• Keren Raz,
• Ronja Driller,
• Thomas Brück,
• Bernhard Loll and
• Dan T. Major

Beilstein J. Org. Chem. 2020, 16, 50–59, doi:10.3762/bjoc.16.7

• with numerous pharmacological [7][8] and biological activities have been reported, rendering them important targets for medical and biotechnology research [9]. Chemical synthetic and sustainable biosynthetic strategies in synergy with the biological activity of different terpene natural products have

SnCl₄-catalyzed solvent-free acetolysis of 2,7-anhydrosialic acid derivatives

• Kesatebrhan Haile Asressu and
• Cheng-Chung Wang

Beilstein J. Org. Chem. 2019, 15, 2990–2999, doi:10.3762/bjoc.15.295

• Kesatebrhan Haile Asressu Cheng-Chung Wang Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan Taiwan International Graduate Program (TIGP), Sustainable Chemical Science and Technology (SCST), Academia Sinica, Taipei 115, Taiwan Department of Applied Chemistry, National Chiao Tung

A green, economical synthesis of β-ketonitriles and trifunctionalized building blocks from esters and lactones

• Daniel P. Pienaar,
• Kamogelo R. Butsi,
• Amanda L. Rousseau and
• Dean Brady

Beilstein J. Org. Chem. 2019, 15, 2930–2935, doi:10.3762/bjoc.15.287

• catalytic amount of isopropanol, or 18-crown-6, was necessary to facilitate the reaction and to reduce side-product formation under ambient conditions. Keywords: acylation; β-ketonitrile; enolizable; trifunctionalized; sustainable; Introduction β-Ketonitriles represent highly versatile intermediates for

Bacterial terpene biosynthesis: challenges and opportunities for pathway engineering

• Eric J. N. Helfrich,
• Geng-Min Lin,
• Christopher A. Voigt and
• Jon Clardy

Beilstein J. Org. Chem. 2019, 15, 2889–2906, doi:10.3762/bjoc.15.283

• research efforts, there is no sustainable synthetic or biosynthetic approach to this molecule. More than half a dozen total syntheses, each requiring 37 steps [15][16] or more [14], have been reported, yielding at best 32 mg of the drug in toto, while the yearly pharmaceutical requirements are greater than

• , recombined, and reused easily for different applications. Insights into terpene biosynthesis, along with advancements in synthetic biology, will pave the way towards the sustainable and selective biotechnological production of high-value terpenes, such as taxol (1). One recent study describes the successful

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

• potential greener and sustainable alternative to traditional redox protocols [1][2][3][4]. Starting from its inception in 1800, EOC has undergone a series of advances with respect to the design of electrochemical cells; the nature of the electrode materials; the applied current or potential; the available

Arylisoquinoline-derived organoboron dyes with a triaryl skeleton show dual fluorescence

• Vânia F. Pais,
• Tristan Neumann,
• Ignacio Vayá,
• M. Consuelo Jiménez,
• Abel Ros and
• Uwe Pischel

Beilstein J. Org. Chem. 2019, 15, 2612–2622, doi:10.3762/bjoc.15.254

• Vania F. Pais Tristan Neumann Ignacio Vaya M. Consuelo Jimenez Abel Ros Uwe Pischel CIQSO – Centre for Research in Sustainable Chemistry and Department of Chemistry, University of Huelva, Campus de El Carmen s/n, 21071 Huelva, Spain Department of Chemistry/Institute of Chemical Technology UPV-CSIC

Current understanding and biotechnological application of the bacterial diterpene synthase CotB2

• Ronja Driller,
• Daniel Garbe,
• Norbert Mehlmer,
• Monika Fuchs,
• Keren Raz,
• Dan Thomas Major,
• Thomas Brück and
• Bernhard Loll

Beilstein J. Org. Chem. 2019, 15, 2355–2368, doi:10.3762/bjoc.15.228

• mutagenesis have exciting applications for the sustainable production of high value bioactive substances. Keywords: biotechnology; CotB2; crystal structure; cyclooctatin; diterpene; reaction mechanism; terpene synthase; Introduction Terpenes represent one of the most diverse groups of natural biomolecules

• subtilis of 9 µM and 10 µM for Micrococcus luteus, respectively [25]. For the sustainable, high yield production of bioactive diterpenoids various aspects have to be considered. One key issue in yielding high recombinant terpene production titers, are metabolic bottlenecks in the precursor supply, which

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

• sustainable method for catalysis because sunlight is an essentially unlimited and thereby “green” natural light source and LEDs – conveniently used for irradiation experiments in the laboratory – are cheap and energy-saving artificial sources for irradiations. The current “working horse” for photoredox

Installation of -SO₂F groups onto primary amides

• Jing Liu,
• Shi-Meng Wang,
• Njud S. Alharbi and
• Hua-Li Qin

Beilstein J. Org. Chem. 2019, 15, 1907–1912, doi:10.3762/bjoc.15.186

• liver [23]. The nucleotide-derived probe 5’-(para-fluorosulfonylbenzoyl)adenosine (5’-FSBA) was used for labelling the second nucleotide binding site, the adenine nucleotide regulatory site [24]. In addition, aryl fluorosulfates have also been widely applied as sustainable alternative to aryl halides in

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

• ][60]. They have been employed for a number of organic reactions viz., hydrosilylation of aldehydes and ketones, acetylation reactions, redox reactions, oxidative esterification, etc. [61][62][63]. Thus, in concern with increasing demand for sustainable development, a growing number of catalytic

• 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

• ethyl glycinate resulted in a 53% yield of the corresponding IP. The method was more atom economic and sustainable than others as it utilized air as a sole oxidant and generated water as the only byproduct. The reaction was carried out between pyridyl esters 102 and benzylamine (35) at 65 °C using

Mechanochemistry II

• José G. Hernández

Beilstein J. Org. Chem. 2019, 15, 1521–1522, doi:10.3762/bjoc.15.154

• Journal of Organic Chemistry in 2017 [1], the global interest in the field of mechanochemistry has continued exponentially growing. Thus, leading to the implementation of mechanochemical techniques across different areas of science. Such tremendous growth has established mechanochemistry as a sustainable

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

• synthesis of diversely functionalized pyrroloacridinones in aqueous medium. A library of compounds was synthesized in a one-step pathway utilizing 10 mol % of the nanoreactor following a sustainable methodology in water with high yields. Keywords: heteroditopic macrocycle; organocatalyst; nanoreactor

• ; pyrroloacridinones; sustainable chemistry; water; Introduction Acridines are a renowned heterocyclic entity not only for their biological activities but also for their fluorescence and chemiluminescence properties. Acridine dyes (e.g., acridine orange, acridine yellow, etc.), are predominantly used in staining of

• , makes them highly valuable in view of sustainable chemical applications. Thus, the development of organocatalytic nanoreactors with new features is indeed important to address greener organic syntheses. On the other hand, the rational design of heterotopic macrocycles has attracted intense interest as

Synthesis of (macro)heterocycles by consecutive/repetitive isocyanide-based multicomponent reactions

• Angélica de Fátima S. Barreto and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2019, 15, 906–930, doi:10.3762/bjoc.15.88

• presents several other advantages besides atom economy, such as higher overall yields, easiness of procedure and work-up [12], less solvent being used, fewer residues being produced, fewer purification steps and time-saving, contributing to a more sustainable process (Scheme 1). The Strecker synthesis of α

Mechanochemistry of supramolecules

• Anima Bose and
• Prasenjit Mal

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

• the amides 47 (Figure 26). The development of sustainable methods for the activation of less-reactive undirected C(sp3)–H bonds is challenging however, highly desired in organic synthesis. Mal and co-workers also demonstrated that acidic C(sp3)–hydrogen bonds within a molecule could be used to control

A chemoenzymatic synthesis of ceramide trafficking inhibitor HPA-12

• Seema V. Kanojia,
• Sucheta Chatterjee,
• Subrata Chattopadhyay and
• Dibakar Goswami

Beilstein J. Org. Chem. 2019, 15, 490–496, doi:10.3762/bjoc.15.42

• can be executed under simple reaction conditions with commercially available and inexpensive materials/reagents. In this regard biocatalytic reactions offer green and sustainable alternative routes to develop asymmetric syntheses of pharmaceuticals with varied stereochemical features [30][31][32][33

Aqueous olefin metathesis: recent developments and applications

• Valerio Sabatino and
• Thomas R. Ward

Beilstein J. Org. Chem. 2019, 15, 445–468, doi:10.3762/bjoc.15.39

• tremendous impact in organic synthesis, enabling a variety of applications in polymer chemistry, drug discovery and chemical biology. Although challenging, the possibility to perform aqueous metatheses has become an attractive alternative, not only because water is a more sustainable medium, but also to

• performing catalysis in a more sustainable medium, it still remains challenging to achieve due to the detrimental effect of water. Despite this limitation, olefin metathesis widely contributes to polymer chemistry, drug discovery and biocatalysis. Several technologies relying on aqueous metathesis have been