N-Arylphenothiazines as strong donors for photoredox catalysis – pushing the frontiers of nucleophilic addition of alcohols to alkenes

• Fabienne Speck,
• David Rombach and
• Hans-Achim Wagenknecht

Beilstein J. Org. Chem. 2019, 15, 52–59, doi:10.3762/bjoc.15.5

• optoelectronic properties of the molecules. Photochemical methods have allowed to overcome some of the current limitations in thermally driven chemistry and to substitute conventional energy demanding chemistry by highly sustainable photochemical methods [3][4][5][6][7][8][9][10][11][12]. Phenothiazines have

Mn-mediated sequential three-component domino Knoevenagel/cyclization/Michael addition/oxidative cyclization reaction towards annulated imidazo[1,2-a]pyridines

• Olga A. Storozhenko,
• Alexey A. Festa,
• Delphine R. Bella Ndoutoume,
• Alexander V. Aksenov,
• Alexey V. Varlamov and
• Leonid G. Voskressensky

Beilstein J. Org. Chem. 2018, 14, 3078–3087, doi:10.3762/bjoc.14.287

• with three or more reactants mixed together, became a valuable tool for the synthetic chemistry to produce diverse and complex compounds in an efficient and sustainable way [14][15][16][17]. The use of oxidative conditions in MCRs was found to be useful [18], but challenging due to difficulty to match

The activity of indenylidene derivatives in olefin metathesis catalysts

• Maria Voccia,
• Steven P. Nolan,
• Luigi Cavallo and
• Albert Poater

Beilstein J. Org. Chem. 2018, 14, 2956–2963, doi:10.3762/bjoc.14.275

• Maria Voccia Steven P. Nolan Luigi Cavallo Albert Poater Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, c/ Mª Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain Department of Chemistry and Center for Sustainable Chemistry, Ghent University

Synthesis of a tyrosinase inhibitor by consecutive ethenolysis and cross-metathesis of crude cashew nutshell liquid

• Jacqueline Pollini,
• Valentina Bragoni and
• Lukas J. Gooßen

Beilstein J. Org. Chem. 2018, 14, 2737–2744, doi:10.3762/bjoc.14.252

• Jacqueline Pollini Valentina Bragoni Lukas J. Goossen Lehrstuhl für Organische Chemie I, Ruhr-Universität Bochum, ZEMOS, Universitätsstraße 150, 44801 Bochum, Germany 10.3762/bjoc.14.252 Abstract A convenient and sustainable three-step synthesis of the tyrosinase inhibitor 2-hydroxy-6

• subsequent hydrogenation step. Overall, the target compound was obtained in an overall yield of 61% based on the unsaturated anacardic acid content and 34% based on the crude CNSL. Keywords: cashew nutshell liquid; cross-metathesis; renewable feedstock; sustainable chemistry; tyrosinase inhibitor

• , undergoes smooth ethenolysis only in dichloromethane as the solvent (Scheme 3). Using more sustainable solvents or no solvent at all, the reaction gave almost no turnover, regardless of the ruthenium catalyst employed. However, as a 1.1 M solution in dichloromethane, the unsaturated components of CNSL were

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

• ligand. B12 is reduced to Co(I) species in the active center by reductases in sustainable processes. The partially π-conjugated system of the corrin ring is less easy to be adducted by free radicals than those of porphyrins. B12 is bound to a number of proteins and acts as a module. Different chemical

• catalysts. Despite extensive research, reproducing B12 enzyme reactions in vitro had been difficult in homogenous solutions. Construction of sustainable catalytic systems inspired by B12 enzymes is another important issue that must be addressed for green chemistry. Due to the above-mentioned unique redox

• principle. Chemical methods are considered as efficient techniques to directly degrade halogenated pollutants. Completely mimicking the complicated dehalorespiration systems requires tedious efforts. The concept of bioinspired chemistry would be an effective methodology to design sustainable systems. To

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

• , authentically mild conditions (40 °C stirring) as well as practical scalability. Keywords: additive-free; catalyst-free; cycloaddition; enaminones; on water; 1,2,3-triazole; Introduction Discovering sustainable chemical syntheses constitutes one central issue of modern organic chemistry. A large number of

• strategies and concepts promoting sustainable syntheses have been conceived over the past decades. Methods employing water as reaction medium are amongst the most promising ones by avoiding the application of volatile organic solvents during the reaction process [1][2][3]. Besides acting as a safer and

• , including those reactions involving valuable C–C [7][8][9][10][11], C–heteroatom [12][13][14][15][16], heteroatom–heteroatom [17][18] bond formation as well as divergent cascade reactions [19][20][21][22][23], are presently taking place to guide the progress of sustainable organic synthesis. 1,2,3-Triazole

Bioinspired cobalt cubanes with tunable redox potentials for photocatalytic water oxidation and CO₂ reduction

• Zhishan Luo,
• Yidong Hou,
• Jinshui Zhang,
• Sibo Wang and
• Xinchen Wang

Beilstein J. Org. Chem. 2018, 14, 2331–2339, doi:10.3762/bjoc.14.208

• reactions. Keywords: CO2 reduction; cobalt cubane; photocatalysis; water oxidation; water splitting; Introduction The direct conversion of solar energy into chemical fuels (e.g., H2, CO and hydrocarbons) through water splitting and carbon fixation reactions is a sustainable solution to environmental

• are typically based on noble metals (e.g., Ru, Ir) [37][38][39][40], which seriously restricts their practical applications. Therefore, the development of effective, stable and sustainable molecular catalysts based on earth-abundant elements is highly desirable [41][42][43]. Inspired by the molecular

Bi-mediated allylation of aldehydes in [bmim][Br]: a mechanistic investigation

• Mrunesh Koli,
• Sucheta Chatterjee,
• Subrata Chattopadhyay and
• Dibakar Goswami

Beilstein J. Org. Chem. 2018, 14, 2198–2203, doi:10.3762/bjoc.14.193

• addressed. In modern era, the development of green chemical routes has become inevitable for sustainable technologies. To this end, RTILs are conceived as eco-friendly solvents due to their low vapor pressure, high stability towards air, moisture and heat, ability to dissolve various substrates, and their

Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry

• Michael K. Bogdos,
• Emmanuel Pinard and
• John A. Murphy

Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179

• achieve this as well. This is the most energetically sustainable way possible to carry out a chemical transformation. A result of this use of the energy of photons is that photochemical transformations often require fewer and/or less reactive (which correlates to toxicity and environmental impact

• ) components than traditional reactions. Organocatalysed photoredox catalysis combines the advantages of both these fields. Thus, it is not only a new field filled with exciting discoveries, but also is sustainable and beneficial in the long term. 1.2 General characteristics of photocatalysts 1.2.1 Brief

• reaction specifically investigated the dimerization of thiols. Some of the experiments carried out by the group were in a flow chemistry set up, exemplifying the scalability of the procedure. In addition, the oxidant that achieves the transformation is molecular oxygen, making this a very sustainable route

Thiocarbonyl-enabled ferrocene C–H nitrogenation by cobalt(III) catalysis: thermal and mechanochemical

• Santhivardhana Reddy Yetra,
• Zhigao Shen,
• Hui Wang and
• Lutz Ackermann

Beilstein J. Org. Chem. 2018, 14, 1546–1553, doi:10.3762/bjoc.14.131

• towards more sustainable base metals [10][11][12][13][14][15][16][17], with considerable progress by earth-abundant cobalt catalysts [18][19][20][21][22]. In this context, well-defined cyclopentadienyl-derived cobalt(III) complexes have proven instrumental for enabling a wealth of C–H transformations [23

• alternative for facilitating sustainable organic syntheses [106]. Thus, we were delighted to observe that the mechanochemical C–H nitrogenations proved likewise viable by thiocarbonyl assistance in an effective manner (Scheme 7). Conclusion In conclusion, we have reported on the unprecedented cobalt-catalyzed

Mild and selective reduction of aldehydes utilising sodium dithionite under flow conditions

• Nicole C. Neyt and
• Darren L. Riley

Beilstein J. Org. Chem. 2018, 14, 1529–1536, doi:10.3762/bjoc.14.129

• chemicals increasing lab safety and direct scalability. These are all beneficial in moving towards more efficient and sustainable techniques in chemical processing [3][4][6][7]. The reduction of carbonyl groups are a standard type of transformation in organic synthesis, however, to date under flow

Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis

• Gwendal Grelier,
• Benjamin Darses and
• Philippe Dauban

Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128

• starting materials. Accordingly, any transformation relying on stoichiometric amounts of these reagents will inevitably produce the same quantity of iodoarene derivatives, which can be considered as a waste in the context of sustainable chemistry. Various strategies, thus, have been described to address

Cobalt–metalloid alloys for electrochemical oxidation of 5-hydroxymethylfurfural as an alternative anode reaction in lieu of oxygen evolution during water splitting

• Jonas Weidner,
• Stefan Barwe,
• Kirill Sliozberg,
• Stefan Piontek,
• Justus Masa,
• Ulf-Peter Apfel and
• Wolfgang Schuhmann

Beilstein J. Org. Chem. 2018, 14, 1436–1445, doi:10.3762/bjoc.14.121

• hence leads to an overall improved energy efficiency for H2 production. In addition, contrary to the “waste product O2”, FDCA can be further utilized, e.g., for production of polyethylene 2,5-furandicarboxylate (PEF), a sustainable polymer analog to polyethylene terephthalate (PET) and thus represents a

Recent applications of chiral calixarenes in asymmetric catalysis

• Mustafa Durmaz,
• Erkan Halay and
• Selahattin Bozkurt

Beilstein J. Org. Chem. 2018, 14, 1389–1412, doi:10.3762/bjoc.14.117

• catalytic supports. Surface modification of MNPs with chiral organocatalysts for asymmetric catalysis provides sustainable materials which could perform chiral transformations robustly and readily [62][63]. In this context, the use of chiral calixarenes is very limited. For the first time, a chiral

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

• towards a sustainable replacement of transition metals. The application of chiral hypervalent iodine reagents is expected to pave the way for new reactions and reagent design in the field of asymmetric synthesis and catalysis. An overview of different chiral iodine reagents or precursors thereof

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• /bjoc.14.61 Abstract Sustainable and environmentally benign production are key drivers for developments in the chemical industrial sector, as protecting our planet has become a significant element that should be considered for every industrial breakthrough or technological advancement. As a result, the

• ; nanoreactors; micelles; polymersomes; Introduction It is widely acknowledged that “the best solvent is no solvent”; however, running a reaction under neat conditions is very challenging from the points of view of mass transfer and temperature gradients [1][2]. Therefore, sustainable chemical technologies are

• switching procedures can be prevented. Although this requires still much development, it is to be expected that in the near future nanoreactors will be key to a more sustainable production of fine chemicals. Assembly of catalyst-functionalized amphiphilic block copolymers into polymer micelles and vesicles

Investigating radical cation chain processes in the electrocatalytic Diels–Alder reaction

• Yasushi Imada,
• Yohei Okada and
• Kazuhiro Chiba

Beilstein J. Org. Chem. 2018, 14, 642–647, doi:10.3762/bjoc.14.51

• highly scalable as well as sustainable. The longer chain length, also referred to as a higher “current efficiency” in this context, would enhance such advantages of the electrochemical synthesis. It should also be noted that the mechanism of electrochemical reactions can easily be studied since the

Electrochemical Corey–Winter reaction. Reduction of thiocarbonates in aqueous methanol media and application to the synthesis of a naturally occurring α-pyrone

• Ernesto Emmanuel López-López,
• José Alvano Pérez-Bautista,
• Fernando Sartillo-Piscil and
• Bernardo A. Frontana-Uribe

Beilstein J. Org. Chem. 2018, 14, 547–552, doi:10.3762/bjoc.14.41

• dangerous conventional redox reagents by sustainable and inexpensive electrical current [16][17][18][19], the ease with which umpolung reactivity is achieved [20][21][22], the access to unstable intermediates of great utility in organic synthesis [23][24][25], and in most of the cases, the use of mild

Latest development in the synthesis of ursodeoxycholic acid (UDCA): a critical review

• Fabio Tonin and
• Isabel W. C. E. Arends

Beilstein J. Org. Chem. 2018, 14, 470–483, doi:10.3762/bjoc.14.33

• transformations [16][17][18][19] or chemoenzymatic procedures [20][21] employing CA, CDCA or lithocholic acid (LCA) as starting material have been studied. This minireview summarises different aspects to be addressed and hurdles to be taken in the development of a selective and sustainable process for the

• processing For an economically and environmentally sustainable process volumetric productivities have to be considered. In other words substrate loadings cannot be too low. While it does not represent a problem in chemical synthesis (UDCA, CDCA and CA are pretty soluble in alcohols like methanol and ethanol

• mM). Therefore, there is much room for improvement and further studies are needed to design a truly sustainable integrated process for the production of UDCA. Abbreviations CA, cholic acid; CDCA, chenodeoxycholic acid; DCA, deoxycholic acid; DHCA, dehydrocholic acid; LCA, lithocholic acid; UCA

Continuous-flow retro-Diels–Alder reaction: an efficient method for the preparation of pyrimidinone derivatives

• Imane Nekkaa,
• Márta Palkó,
• István M. Mándity and
• Ferenc Fülöp

Beilstein J. Org. Chem. 2018, 14, 318–324, doi:10.3762/bjoc.14.20

• addition, they are present in several natural frameworks [42][43][44]. We wanted to exploit the benefits of flow processing for reaction optimization and synthesis and develop novel sustainable synthetic methodologies with possible useful applications for the pharmaceutical industry. Our results show that

Nucleophilic fluoroalkylation/cyclization route to fluorinated phthalides

• Masanori Inaba,
• Tatsuya Sakai,
• Shun Shinada,
• Tsuyuka Sugiishi,
• Yuta Nishina,
• Norio Shibata and
• Hideki Amii

Beilstein J. Org. Chem. 2018, 14, 182–186, doi:10.3762/bjoc.14.12

• Sustainable Manufacturing at Low Energy, Low Environmental Load) is acknowledged. We would like to thank Prof. Hiroshi Sano (Gunma University) for his useful suggestions.

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation and chlorination. Part 2: Use of CF₃SO₂Cl

• Hélène Chachignon,
• Hélène Guyon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2800–2818, doi:10.3762/bjoc.13.273

• pharmaceutical and agrochemical industries in which new opportunities for economical and sustainable development are eagerly sought after. Numerous applications and novel reactions are expected to appear, thus contributing to enrich the bright future of trifluoromethanesulfonyl chloride. Trifluoromethylation of

Synthesis and photophysical properties of novel benzophospholo[3,2-b]indole derivatives

• Mio Matsumura,
• Mizuki Yamada,
• Atsuya Muranaka,
• Misae Kanai,
• Naoki Kakusawa,
• Daisuke Hashizume,
• Masanobu Uchiyama and
• Shuji Yasuike

Beilstein J. Org. Chem. 2017, 13, 2304–2309, doi:10.3762/bjoc.13.226

• Chemistry Research Team, RIKEN Center for Sustainable Resource Science (CSRS), Wako 351-0198, Japan Faculty of Pharmaceutical Sciences, Hokuriku University, Ho-3 Kanagawa-machi, Kanazawa 920-1181, Japan Materials Characterization Support Unit, RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198

Peptide synthesis: ball-milling, in solution, or on solid support, what is the best strategy?

• Ophélie Maurin,
• Pascal Verdié,
• Gilles Subra,
• Frédéric Lamaty,
• Jean Martinez and
• Thomas-Xavier Métro

Beilstein J. Org. Chem. 2017, 13, 2087–2093, doi:10.3762/bjoc.13.206

• build more efficient and sustainable peptide syntheses in the near future. Keywords: ball-mill; green chemistry; mechanochemistry; peptide synthesis; SPPS; Introduction Peptides play a central role both in biological mechanisms and in therapeutic solutions of the future [1][2]. Pharmaceutical

Main group mechanochemistry

• Agota A. Gečiauskaitė and
• Felipe García

Beilstein J. Org. Chem. 2017, 13, 2068–2077, doi:10.3762/bjoc.13.204

• sustainable alternatives to conventional solvent-based synthetic routes. Mechanochemistry has already been successfully applied to the synthesis of active pharmaceutical ingredients (APIs), organic compounds, metal oxides, coordination compounds and organometallic complexes. In the main group arena, examples

• group compounds and frameworks. Keywords: ball milling; main group; mechanochemical synthesis; mechanochemistry; Introduction The original mainspring for the current expansion of solid state methodologies is the need for cleaner, safer and sustainable chemical transformations – particularly since raw

• ], and recent advances continue to propel the importance of this field in the 21st century [71]. For instance, developments in fundamental main group chemistry are pivotal in providing the necessary knowledge and tools for the more sustainable chemical processes, from “blue-skies” to applied research and