Olefin metathesis in air

• Lorenzo Piola,
• Fady Nahra and
• Steven P. Nolan

Beilstein J. Org. Chem. 2015, 11, 2038–2056, doi:10.3762/bjoc.11.221

• reaction with styrene, avoiding the use of hazardous diazo compound 7 [82]. Towards the end of 2013, a report by Olszewski, Skowerski and co-workers showed how a variety of commercially available catalysts (Figure 12) could be employed in air with nondegassed ACS grade green solvents. Their results were in

Hexacoordinate Ru-based olefin metathesis catalysts with pH-responsive N-heterocyclic carbene (NHC) and N-donor ligands for ROMP reactions in non-aqueous, aqueous and emulsion conditions

• Shawna L. Balof,
• K. Owen Nix,
• Matthew S. Olliff,
• Sarah E. Roessler,
• Arpita Saha,
• Kevin B. Müller,
• Ulrich Behrens,
• Edward J. Valente and
• Hans-Jörg Schanz

Beilstein J. Org. Chem. 2015, 11, 1960–1972, doi:10.3762/bjoc.11.212

• combination of a wide range of substrates and solvents [9][10][11][12]. Over the past decade, Ru–alkylidene based olefin metathesis in aqueous media has become increasingly important [13]. Benefits such as the non-hazardous, vastly abundant and commercially highly attractive of water coupled with a high heat

The synthesis of active pharmaceutical ingredients (APIs) using continuous flow chemistry

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2015, 11, 1194–1219, doi:10.3762/bjoc.11.134

• of such processes, but also enables the chemist to perform more potentially hazardous and otherwise forbidden transformations in a safer and more reliable fashion [16][17][18][19][20][21]. The main advantages cited for improved operational safety are principally the reduced inventories of reactive

• inventory of the reactive intermediate reduced the safety concerns associated with the use of the azide. The choice of flow when handling hazardous materials like azides is a very frequently encountered driver and several publications detailing the associated benefits have emerged over the years [88][89][90

Are D-manno-configured Amadori products ligands of the bacterial lectin FimH?

• Tobias-Elias Gloe,
• Insa Stamer,
• Cornelia Hojnik,
• Tanja M. Wrodnigg and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2015, 11, 1096–1104, doi:10.3762/bjoc.11.123

• yield of 85% from 6. This is a synthetic route to aldoheptoses 8a and 8b alternative to the one reported [2] with the advantage that the use of environmental hazardous as well as highly toxic HCN is not required. Amadori rearrangement of the diasteromeric mixture 8 with an amine of choice allows an

Radical-mediated dehydrative preparation of cyclic imides using (NH₄)₂S₂O₈–DMSO: application to the synthesis of vernakalant

• Dnyaneshwar N. Garad,
• Subhash D. Tanpure and
• Santosh B. Mhaske

Beilstein J. Org. Chem. 2015, 11, 1008–1016, doi:10.3762/bjoc.11.113

• distillation [46]. Imide synthesis methodologies starting from different types of starting materials also have been reported [47][48][49][50][51][52][53][54]. However, low yields, use of acidic conditions, lack of generality, use of expensive and toxic metal catalysts or reagents, formation of hazardous

3-Glucosylated 5-amino-1,2,4-oxadiazoles: synthesis and evaluation as glycogen phosphorylase inhibitors

• Marion Donnier-Maréchal,
• David Goyard,
• Vincent Folliard,
• Tibor Docsa,
• Pal Gergely,
• Jean-Pierre Praly and
• Sébastien Vidal

Beilstein J. Org. Chem. 2015, 11, 499–503, doi:10.3762/bjoc.11.56

• from carbonyl diimidazole was not successful [30], and since phosgene was not considered due to its hazardous reaction conditions, ureas 2b–d could be readily prepared from triphosgene 1 (as a phosgene precursor) and the corresponding amines (Scheme 1). While treatment of triphosgene with the

Chemoselective O-acylation of hydroxyamino acids and amino alcohols under acidic reaction conditions: History, scope and applications

• Tor E. Kristensen

Beilstein J. Org. Chem. 2015, 11, 446–468, doi:10.3762/bjoc.11.51

Electrochemical oxidation of cholesterol

• Jacek W. Morzycki and
• Andrzej Sobkowiak

Beilstein J. Org. Chem. 2015, 11, 392–402, doi:10.3762/bjoc.11.45

• –Takeya [33][34] groups. The oxidation of cholesteryl acetate with hydrogen peroxide or peracetic acid catalyzed by these complexes varied depending on the solvent used and the reaction conditions. To avoid the use of hazardous peroxy reagents, an electrochemical system was invented, which can be

Visible-light-induced bromoetherification of alkenols for the synthesis of β-bromotetrahydrofurans and -tetrahydropyrans

• Run Lin,
• Hongnan Sun,
• Chao Yang,
• Youdong Yang,
• Xinxin Zhao and
• Wujiong Xia

Beilstein J. Org. Chem. 2015, 11, 31–36, doi:10.3762/bjoc.11.5

• alkenes have received considerable attention from chemists, and various approaches have been made in this area. Initially, the classical synthetic pathway for bromocyclization proceeds utilizing bromine [10]. However, molecular bromine is hazardous and difficult to handle. Further research show that N

First chemoenzymatic stereodivergent synthesis of both enantiomers of promethazine and ethopropazine

• Paweł Borowiecki,
• Daniel Paprocki and
• Maciej Dranka

Beilstein J. Org. Chem. 2014, 10, 3038–3055, doi:10.3762/bjoc.10.322

• of the reaction [11][12][13]. In addition, the easy handling (not involving the use of a complex chemical apparatus), possibility of catalyst recovery, mild experimental (room temperature, atmospheric pressure, etc.) and non-hazardous environmental conditions as well as organic solvent-, moisture

Sequential decarboxylative azide–alkyne cycloaddition and dehydrogenative coupling reactions: one-pot synthesis of polycyclic fused triazoles

• Kuppusamy Bharathimohan,
• Thanasekaran Ponpandian,
• A. Jafar Ahamed and
• Nattamai Bhuvanesh

Beilstein J. Org. Chem. 2014, 10, 3031–3037, doi:10.3762/bjoc.10.321

• several advantages over the classical C–C bond formation method including the stability and preparation of the starting material and the non-hazardous byproducts. In 2011, Kolarovič et al. [6] first reported the copper-catalyzed decarboxylative [3 + 2] cycloaddition reaction of 2-alkynoic acid with

Recent advances in the electrochemical construction of heterocycles

• Robert Francke

Beilstein J. Org. Chem. 2014, 10, 2858–2873, doi:10.3762/bjoc.10.303

• the use of an expensive catalyst and/or toxic and hazardous reagents. In order to meet increasing environmental and economic constraints, further efforts should be directed towards the development of mild and reagent-free methods [17][18]. In this context, electroorganic synthesis can provide an

• interesting and practical alternative to conventional methods for heterocycle synthesis [19][20]. Since toxic and hazardous redox reagents are either replaced by electric current (direct electrolysis) or generated in situ from stable and non-hazardous precursors (indirect electrolysis), electrosynthesis is

Removal of volatile organic compounds using amphiphilic cyclodextrin-coated polypropylene

• Ludmilla Lumholdt,
• Sophie Fourmentin,
• Thorbjørn T. Nielsen and
• Kim L. Larsen

Beilstein J. Org. Chem. 2014, 10, 2743–2750, doi:10.3762/bjoc.10.290

• suspected to be hazardous to the aquatic environment and/or human health [2] thus the maximum concentration limit in wastewater was set in the ppb range [1]. In the literature, various alternative wastewater treatment methods, such as treatment with active carbon or ozone, have been investigated but none

Electrocarboxylation: towards sustainable and efficient synthesis of valuable carboxylic acids

• Roman Matthessen,
• Jan Fransaer,
• Koen Binnemans and
• Dirk E. De Vos

Beilstein J. Org. Chem. 2014, 10, 2484–2500, doi:10.3762/bjoc.10.260

• hazardous reducing agents by clean electrons. In this case, the high thermodynamic stability of CO2 is by-passed by a simple one-electron reduction at an electrode, leading to in situ generation of reactive intermediates. Often, room temperature conditions are sufficient, considering that the energy of the

• ]. The electrocarboxylation of organic halides can also be considered as an alternative dechlorination pathway for chlorobenzenes [122] and polychloromethanes [142]. While the synthesis of halogenated reagents is rather hazardous, the electrocarboxylation of organic halides is an interesting method to

• for the hazardous synthesis via alkali metal cyanides [137][145][146]. Derivatives of cyanoacetic acid are precious starting materials in pharmaceutical and agrochemical synthesis [137]. When the anodic reaction is the oxidation of a halide, lower current efficiencies can be attributed to a successive

Oxidative phenylamination of 5-substituted 1-hydroxynaphthalenes to N-phenyl-1,4-naphthoquinone monoimines by air and light “on water”

• Julio Benites,
• Juan Meléndez,
• Cynthia Estela,
• David Ríos,
• Luis Espinoza,
• Iván Brito and
• Jaime A. Valderrama

Beilstein J. Org. Chem. 2014, 10, 2448–2452, doi:10.3762/bjoc.10.255

• conventional oxidative phenylamination procedures, this novel synthetic method offers the advantage of aerobic conditions “on water” instead of hazardous oxidant reagents currently employed in aqueous alcoholic media. Keywords: 1,4-naphthoquinone monoimines; on water; oxidative coupling; rose bengal; solar

Synthesis of α-amino amidines through molecular iodine-catalyzed three-component coupling of isocyanides, aldehydes and amines

• Praveen Reddy Adiyala,
• D. Chandrasekhar,
• Jeevak Sopanrao Kapure,
• Chada Narsimha Reddy and
• Ram Awatar Maurya

Beilstein J. Org. Chem. 2014, 10, 2065–2070, doi:10.3762/bjoc.10.214

• ], ZnO nanoparticles [18] and BF3·OEt2 [19] were reported with varying degrees of success. All these reported methods for the preparation of α-amino amidines have their own limitations such as long reaction times, high catalyst loading and use of expensive and hazardous metal catalysts. Therefore, the

Supercritical carbon dioxide: a solvent like no other

• Jocelyn Peach and
• Julian Eastoe

Beilstein J. Org. Chem. 2014, 10, 1878–1895, doi:10.3762/bjoc.10.196

• on the philosophy of green chemistry, a concept encouraging the design of chemically efficient products and processes that reduce or eliminate the use or generation of hazardous substances [1]. This can, in theory, be achieved through the application of a set of ‘principles’, including reduced use

• chemical processing and as a solvent [3], thus replacing the volatile organic compounds (VOCs) that are currently commonly used [4]. These VOCs are environmentally hazardous and notoriously difficult to dispose of so a reduction in use would improve the sustainability of many chemical processes. As well as

Nonanebis(peroxoic acid): a stable peracid for oxidative bromination of aminoanthracene-9,10-dione

• Vilas Venunath Patil and
• Ganapati Subray Shankarling

Beilstein J. Org. Chem. 2014, 10, 921–928, doi:10.3762/bjoc.10.90

• ) [18][19][20][21]. In all processes, hazardous molecular bromine is used as a bromine source [11][12][13][14][15][16][17][18][19][20][21]. Ghaieni et. al. [22][23] have reported bromination of aminoanthracene-9,10-dione in a mixture of conc sulfuric acid with chlorobenzene, glacial acetic acid

Continuous flow nitration in miniaturized devices

• Amol A. Kulkarni

Beilstein J. Org. Chem. 2014, 10, 405–424, doi:10.3762/bjoc.10.38

• of a special stainless steel alloy (1.4361, X1CrNiSi18154). Electrical heaters and two integrated water coolers were used for heat transfer in different sections of the integrated reactor. The integration of these functions in one setup facilitates the handling of hazardous chemicals at higher

Flow microreactor synthesis in organo-fluorine chemistry

• Hideki Amii,
• Aiichiro Nagaki and
• Jun-ichi Yoshida

Beilstein J. Org. Chem. 2013, 9, 2793–2802, doi:10.3762/bjoc.9.314

• microreactor technology to overcome long-standing problems in synthetic organofluorine chemistry are showcased. Reactions using hazardous fluorinating reagents Direct fluorination employing elemental fluorine (F2) is one of the most straightforward methods to make fluorine-containing molecules with high atom

• ][40]. Direct fluorination of aromatics in microreactor system took place cleanly [36]. As another splendid example for safe handling of hazardous fluorinating reagents, the flow microreactor synthesis using diethylaminosulfur trifluoride (Et2NSF3, abbreviated as DAST) was demonstrated. DAST is a

Silica sulfuric acid: a reusable solid catalyst for one pot synthesis of densely substituted pyrrole-fused isocoumarins under solvent-free conditions

• Sudipta Pathak,
• Kamalesh Debnath and
• Animesh Pramanik

Beilstein J. Org. Chem. 2013, 9, 2344–2353, doi:10.3762/bjoc.9.269

• ]. Although these methods are useful for the synthesis of isocoumarin derivatives, the reactions involved in the synthesis still suffer from some serious limitations such as the use of expensive and hazardous reagents [12] and toxic metal catalysts [10][11][15][17]. Some of the reactions need laborious and

Bis(benzylamine) monomers: One-pot preparation and application in dendrimer scaffolds for removing pyrene from aqueous environments

• Olivia N. Monaco,
• Sarah C. Tomas,
• Meghan K. Kirrane and
• Amy M. Balija

Beilstein J. Org. Chem. 2013, 9, 2320–2327, doi:10.3762/bjoc.9.266

• carboxylic acid group must be masked, and the intermediates must be purified through column chromatography [16]. Furthermore, although many benzyl bromide compounds are commercially available, they are typically lachrymators and are considered hazardous as compared with their benzaldehyde counterparts

• . Therefore, the bisimine and bisamine synthesis disclosed in this paper are ideal for the generation of functionalized systems with a higher molecular weight without the use of hazardous reagents or generating large quantities of waste as compared with previously published systems. Bisimine 3a was stable to

Gold-catalyzed regioselective oxidation of propargylic carboxylates: a reliable access to α-carboxy-α,β-unsaturated ketones/aldehydes

• Kegong Ji,
• Jonathan Nelson and
• Liming Zhang

Beilstein J. Org. Chem. 2013, 9, 1925–1930, doi:10.3762/bjoc.9.227

• permits a safe and efficient access to α-oxo gold carbenes without resorting to the dediazotization strategy [3][4][5] using hazardous and potentially explosive diazo substrates (Scheme 1). Since then an array of versatile synthetic methods has been developed based on the general approach by us [2][6][7

Efficient continuous-flow synthesis of novel 1,2,3-triazole-substituted β-aminocyclohexanecarboxylic acid derivatives with gram-scale production

• Sándor B. Ötvös,
• Ádám Georgiádes,
• István M. Mándity,
• Lóránd Kiss and
• Ferenc Fülöp

Beilstein J. Org. Chem. 2013, 9, 1508–1516, doi:10.3762/bjoc.9.172

• , the scalability of CF procedures is a straightforward function of time and the flow rate, and the risks associated with the accumulation of hazardous species are minimized, because the solution of the reactants is eluting continuously from the active zone of the reactor [33][34][44][45][60]. The CF

Camera-enabled techniques for organic synthesis

• Steven V. Ley,
• Richard J. Ingham,
• Matthew O’Brien and
• Duncan L. Browne

Beilstein J. Org. Chem. 2013, 9, 1051–1072, doi:10.3762/bjoc.9.118

• hazardous gases are to be used. In this case, the reactor configuration was calibrated by a colourimetric calibration using another dye, bromocresol green (Supporting Information File 3 shows an acidic solution of bromocresol green changing colour under an ammonia atmosphere). The ammonia-enriched solvent