Graphitic carbon nitride prepared from urea as a photocatalyst for visible-light carbon dioxide reduction with the aid of a mononuclear ruthenium(II) complex

• Kazuhiko Maeda,
• Daehyeon An,
• Ryo Kuriki,
• Daling Lu and
• Osamu Ishitani

Beilstein J. Org. Chem. 2018, 14, 1806–1812, doi:10.3762/bjoc.14.153

• using cobalt-based metal complexes as reduction cocatalysts [17][18][19][20]. In these systems, structural properties of g-C3N4 such as specific surface area and porosity have a strong impact on activity, because they strongly affect the efficiency of electron/hole utilization to the surface chemical

• reactions [21][22]. Apart from mpg-C3N4 that is usually prepared by a hard-template method with multistep procedures [9][23], g-C3N4 having a relatively higher surface area can be readily prepared by heating urea, which is an inexpensive and readily available precursor, in air [14][24]. In fact, the urea

One hundred years of benzotropone chemistry

• Arif Dastan,
• Haydar Kilic and
• Nurullah Saracoglu

Beilstein J. Org. Chem. 2018, 14, 1120–1180, doi:10.3762/bjoc.14.98

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

• worm-like micelles, form when 1/3 ≤ p ≤ 1/2. A typical micelle acquires a hydrophobic core that is able to accommodate hydrophobic catalysts, providing thermodynamic and kinetic control over chemical reactions [31]. Moreover, carrying out reactions in such a hydrophobic core leads to a concentration

Synthesis and stability of strongly acidic benzamide derivatives

• Frederik Diness,
• Niels J. Bjerrum and
• Mikael Begtrup

Beilstein J. Org. Chem. 2018, 14, 523–530, doi:10.3762/bjoc.14.38

• stability under acidic and basic conditions are also reported. Keywords: benzoic acid; cross-coupling; hydrolysis; SNAr; trifluoromethanesulfonamide; Introduction Very strong organic acids are interesting as catalysts for chemical reactions [1][2] and for facilitation of proton conduction [3]. In order to

• p-toluenesulfonic acid (5) which is commonly used as a soluble organic acid catalyst in chemical reactions. Remarkably, neither the N-triflylbenzamides nor the N,N’-bis(triflyl)benzimidamides have been studied as Brønsted acid catalysts. Their chemical stability including compatibility with

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

• allow the access to elevated temperatures and pressures accredited to superheating of organic solvents in a controlled and safe fashion [6][14][15][16][17]. The accurate tuning of residence time can further broaden the versatility of CF processes by governing the outcome of chemical reactions

Fluorogenic PNA probes

• Tirayut Vilaivan

Beilstein J. Org. Chem. 2018, 14, 253–281, doi:10.3762/bjoc.14.17

• the unmasking of quenched or caged fluorophores by chemical reactions, such as the Staudinger reaction [98][99][100][101], hydrolysis [102] and group transfer mediated by nucleophilic substitution [103][104]. Optimizing the conditions requires a good balance between the affinity of the probe to the

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF₃SO₂Na

• Hélène Guyon,
• Hélène Chachignon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

• acetanilides or anilines were obtained as sole products [59]. To meet high expectations of environmentally low impact chemical reactions, Lipshutz and co-workers carried out the trifluoromethylation of heterocycles using aqueous micellar conditions based on the surfactant TPGS−750−M in water at room

Exploring mechanochemistry to turn organic bio-relevant molecules into metal-organic frameworks: a short review

• Vânia André,
• Sílvia Quaresma,
• João Luís Ferreira da Silva and
• M. Teresa Duarte

Beilstein J. Org. Chem. 2017, 13, 2416–2427, doi:10.3762/bjoc.13.239

• and Jean-Marie Lehn [52][53][54][55]. The energetics involved in supramolecular chemical reactions are not very severe, making mechanochemistry an excellent technique to be used in these processes. In this short review, we particularly focused on the application of mechanochemistry to the synthesis of

Mechanochemistry

• José G. Hernández

Beilstein J. Org. Chem. 2017, 13, 2372–2373, doi:10.3762/bjoc.13.234

• otherwise impossible chemical reactivity in many cases. From a green chemistry perspective, mechanochemical activation conducted by milling, shearing, pulling or ultrasonic irradiation allows for the possibility to drastically reduce the amount of solvent needed during chemical reactions, even to the point

Synthesis and application of trifluoroethoxy-substituted phthalocyanines and subphthalocyanines

• Satoru Mori and
• Norio Shibata

Beilstein J. Org. Chem. 2017, 13, 2273–2296, doi:10.3762/bjoc.13.224

• the targeted position in the four units using chemical reactions [64][65]. This is because the selective reaction of phthalocyanine is unexplored and removal of byproducts after the reaction is difficult due to its aggregation properties. On the other hand, TFEO-Pcs have high solubility, and chemical

The effect of milling frequency on a mechanochemical organic reaction monitored by in situ Raman spectroscopy

• Patrick A. Julien,
• Ivani Malvestiti and
• Tomislav Friščić

Beilstein J. Org. Chem. 2017, 13, 2160–2168, doi:10.3762/bjoc.13.216

• , have emerged as a highly versatile and general route to conduct chemical reactions in the absence of bulk solvents [2]. Indeed, the demonstrated versatility in organic [5][6][7][8], organometallic [9][10], pharmaceutical [11][12], supramolecular [13], metal-organic [14][15], and materials synthesis [16

• effect of milling frequency on the reaction rate. The systematic studies were conducted by measuring Raman spectra for chemical reactions that were, to the best of our ability, identical in all respects except the choice of milling frequency, i.e., the choice of milling media, the jar volume and material

Main group mechanochemistry

• Agota A. Gečiauskaitė and
• Felipe García

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

• metal leaching [28], rates of wearing [25], and/or promoting chemical reactions [9][29][30][31][32][33] must also be taken into account when selecting appropriate milling media. In addition to variable mechanical and milling media parameters, an alternative approach to controlling the mechanochemical

One-pot multistep mechanochemical synthesis of fluorinated pyrazolones

• Joseph L. Howard,
• William Nicholson,
• Yerbol Sagatov and
• Duncan L. Browne

Beilstein J. Org. Chem. 2017, 13, 1950–1956, doi:10.3762/bjoc.13.189

• chemical reactions in such a manner is desirable as reactions are consequently less wasteful and more environmentally benign than the analogous solution-based approaches, especially if the work-up and purification processes can also be made solventless or solvent minimised [1][2]. As such, there is now a

Mechanochemical synthesis of small organic molecules

• Tapas Kumar Achar,
• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

• /energy, etc. Non-conventional energy sources for chemical reactions such as microwave, mechanical mixing, visible-light and ultrasound are becoming surge of interest to the chemist as alternative energy sources in laboratories [7]. By imposing these techniques innumerable chemical transformations have

• methods for the mechano-chemical generation of reactive sites, usually macroradicals, in polymer chains that undergo mechano-chemical reactions’ [15]. The mechanistic understanding of mechanochemical reactions is still unclear [16]. A single idea could not be conceived because of the diversified nature of

Solvent-free sonochemistry: Sonochemical organic synthesis in the absence of a liquid medium

• Deborah E. Crawford

Beilstein J. Org. Chem. 2017, 13, 1850–1856, doi:10.3762/bjoc.13.179

• . Keywords: mechanochemistry; organic; solvent-free; sonochemistry; synthesis; Introduction Mechanochemistry is typically regarded as the grinding of solid reagents in a ball mill (or mortar and pestle), to instigate and accelerate chemical reactions [1]. In recent years, mechanochemistry has evolved to

• studying a larger scope of chemical reactions and the mechanism behind which the liquid/solvent-free reactions occur. It also provides a means of applying a gentler form of mechanical energy to a system which may increase the range of organic and inorganic mechanochemical transformations that can be

Mechanochemical synthesis of thioureas, ureas and guanidines

• Vjekoslav Štrukil

Beilstein J. Org. Chem. 2017, 13, 1828–1849, doi:10.3762/bjoc.13.178

• -based organocatalysts are shown. Green Chemistry, which aims at turning chemical reactions into more effective and sustainable processes with high conversions of the starting materials and no byproduct formation, has emerged as a mainstream paradigm in chemical research in the past 25 years. Anastas and

• , plastic) and even milling atmosphere allows reproducible solid state syntheses in such instruments. The progress made over the past 15 years has transformed grinding or milling from a purely physical tool for mechanical processing into a synthetic method of choice when one wishes to conduct chemical

• reactions in an environmentally-friendly fashion [17][18]. In this respect, there have been several turning points in the development of solid-state mechanochemistry. The first key discovery was made by Jones et al. who discovered the rate-accelerating effect of adding small catalytic quantities of a liquid

Selective enzymatic esterification of lignin model compounds in the ball mill

• Ulla Weißbach,
• Saumya Dabral,
• Laure Konnert,
• Carsten Bolm and
• José G. Hernández

Beilstein J. Org. Chem. 2017, 13, 1788–1795, doi:10.3762/bjoc.13.173

• ), showed the highest selectivity and could also be recycled by centrifugation and reused with little loss in stereoselectivity after four consecutive cycles [10]. Besides the above stated, one additional advantage of mechanochemistry includes the possibility to overcome solubility restrictions in chemical

• reactions involving reactants of poor solubility. This characteristic feature of mechanochemistry has proven fundamental while dealing with chemically induced cleavage of biomaterials such as lignin [11][12], cellulose [13][14][15] or chitin [16]. In regard to lignin chemistry, solution-based lignin

Mechanochemical N-alkylation of imides

• Anamarija Briš,
• Mateja Đud and
• Davor Margetić

Beilstein J. Org. Chem. 2017, 13, 1745–1752, doi:10.3762/bjoc.13.169

• synthesis of amines by their reaction with 1,2-diaminoethane. Keywords: ball milling; Gabriel reaction; imides; mechanochemistry; N-alkylation; Introduction The development of environmentally friendly organic reactions is a growing area of interest [1]. The reduction of the impact of chemical reactions on

Chemical systems, chemical contiguity and the emergence of life

• Terrence P. Kee and
• Pierre-Alain Monnard

Beilstein J. Org. Chem. 2017, 13, 1551–1563, doi:10.3762/bjoc.13.155

• plausible conditions. These chemicals were then considered indispensable for the emergence and evolution of cellular life, and were extensively studied using simple chemical reactions or selection schemes to evolve them and enable novel functions. Many insights were gained and have allowed for a better

Grip on complexity in chemical reaction networks

• Albert S. Y. Wong and
• Wilhelm T. S. Huck

Beilstein J. Org. Chem. 2017, 13, 1486–1497, doi:10.3762/bjoc.13.147

• systems within a synthetic chemical framework. Living systems rely on complex networks of chemical reactions to control the concentration of molecules in space and time. Despite the enormous complexity in biological networks, it is possible to identify network motifs that lead to functional outputs such

• the behavior that emerges from complex networks of chemical reactions [16]. Vast metabolic and genetic networks of chemical reactions allow living cells to sense their environment, react to stimuli, and use nutrients for cell growth and division. In the past decades, complexity science has made

• the design principles of biological systems into a practical “programming language” and learn how to create functionality using chemical reactions. Early work has resulted in numerous exciting examples, ranging from functional out-of-equilibrium systems that can perform logic operations, to

Mechanochemical borylation of aryldiazonium salts; merging light and ball milling

• José G. Hernández

Beilstein J. Org. Chem. 2017, 13, 1463–1469, doi:10.3762/bjoc.13.144

• aforementioned context makes one wonder about the potential for conducting chemical reactions under simultaneous photo- and mechanical activation. To test this idea, the photocatalyzed borylation of aryldiazonium salts, first reported in solution by Yan and co-workers was selected as a model reaction [18]. In

Nitration of 5,11-dihydroindolo[3,2-b]carbazoles and synthetic applications of their nitro-substituted derivatives

• Roman A. Irgashev,
• Nikita A. Kazin,
• Gennady L. Rusinov and
• Valery N. Charushin

Beilstein J. Org. Chem. 2017, 13, 1396–1406, doi:10.3762/bjoc.13.136

• anthraquinones. Anyway, the discussed transformation is the case of unusual reduction of nitroaromatic compounds. In general, the chemical reactions, leading to direct displacement of the nitro group in nitroarenes with a hydrogen atom, are rare phenomena. For instance, we can mention the reaction of

Framing major prebiotic transitions as stages of protocell development: three challenges for origins-of-life research

• Ben Shirt-Ediss,
• Sara Murillo-Sánchez and
• Kepa Ruiz-Mirazo

Beilstein J. Org. Chem. 2017, 13, 1388–1395, doi:10.3762/bjoc.13.135

• -life simplifications that do not completely erase this aspect at the beginning. The combination of diverse chemical reactions with self-organization and self-assembly processes in heterogeneous, multi-phase conditions could actually be crucial at those first stages: this is the main assumption that

• move the field of origins of life forward would be to couple simple chemistry to prebiotic vesicle dynamics: chemical reactions provide the power for endogenous synthesis and vesicles the adequate scaffolding for the functional integration of what is synthesized. We will proceed briefly with the issue

Mechanochemistry-assisted synthesis of hierarchical porous carbons applied as supercapacitors

• Desirée Leistenschneider,
• Nicolas Jäckel,
• Felix Hippauf,
• Volker Presser and
• Lars Borchardt

Beilstein J. Org. Chem. 2017, 13, 1332–1341, doi:10.3762/bjoc.13.130

• of synthesis steps and to minimize waste accumulation, at best by avoiding any solvents [7][31]. Lately, mechanochemistry has gained momentum in organic chemistry [32][33][34]. The initiation of chemical reactions by mechanical forces enables organic and inorganic syntheses without the use of any

Biomimetic molecular design tools that learn, evolve, and adapt

• David A Winkler

Beilstein J. Org. Chem. 2017, 13, 1288–1302, doi:10.3762/bjoc.13.125

• biological sciences. For example, they have recently been applied to predicting the feasibility of chemical reactions by learning relationships between the molecular properties of the reaction partners and the outcomes of the reactions in a large database [15]. Another recent example is the robot scientists