Catalytic asymmetric synthesis of biologically important 3-hydroxyoxindoles: an update

• Bin Yu,
• Hui Xing,
• De-Quan Yu and
• Hong-Min Liu

Beilstein J. Org. Chem. 2016, 12, 1000–1039, doi:10.3762/bjoc.12.98

• amino alcohol catalysts were generated in situ from the corresponding amino acids L-Leu or L-Val through the BH3-mediated reduction, making the multi-step synthesis more efficient and environmentally friendly. Diamine catalysts In 2013, Chimni and co-workers reported the diamine catalyst (cat. 10

Three new trixane glycosides obtained from the leaves of Jungia sellowii Less. using centrifugal partition chromatography

• Luíse Azevedo,
• Larissa Faqueti,
• Marina Kritsanida,
• Antonia Efstathiou,
• Despina Smirlis,
• Gilberto C. Franchi Jr,
• Grégory Genta-Jouve,
• Sylvie Michel,
• Louis P. Sandjo,
• Raphaël Grougnet and
• Maique W. Biavatti

Beilstein J. Org. Chem. 2016, 12, 674–683, doi:10.3762/bjoc.12.68

• antiprotozoal activity. Liquid–liquid partition and CPC turned to be a versatile technique of glycoside purification which is environmentally friendly and requires a limited amount of organic solvents. Keywords: CPC; guaiane; Jungia; trixanolide; Introduction Jungia (Asteraceae) comprises shrubs, lianas and

Elucidation of a masked repeating structure of the O-specific polysaccharide of the halotolerant soil bacteria Azospirillum halopraeferens Au4

• Elena N. Sigida,
• Yuliya P. Fedonenko,
• Alexander S. Shashkov,
• Nikolay P. Arbatsky,
• Evelina L. Zdorovenko,
• Svetlana A. Konnova,
• Vladimir V. Ignatov and
• Yuriy A. Knirel

Beilstein J. Org. Chem. 2016, 12, 636–642, doi:10.3762/bjoc.12.62

• environmental factors, among which soil salinity is one of the most stressful. As halotolerant plant-growth-promoting rhizobacteria are environmentally friendly and energy efficient, they attract attention as promising biotechnological agents for combating crop salinity stress [2]. These microorganisms mitigate

Enabling technologies and green processes in cyclodextrin chemistry

• Giancarlo Cravotto,
• Marina Caporaso,
• Laszlo Jicsinszky and
• Katia Martina

Beilstein J. Org. Chem. 2016, 12, 278–294, doi:10.3762/bjoc.12.30

• ferromagnetic materials by grinding under less-environmentally friendly conditions in this case. The components were prepared using classic methods and the final composite was obtained by ball milling of arc-melted MnBi particles and Fe-Co nanoparticles prepared with the aid of a β-CD/oleic acid complex. The

• highlight the huge advantages and potential scalability of these so-called enabling technologies that maximize heat and mass transfer. Although many advances have been made during the past decade, the most exciting results in this field are surely yet to come. Ultrasound US irradiation is an environmentally

• friendly technique that is well suited to the selective chemical modification of CDs from native α-, β- and γ-CD. The use of this method in heterogeneous phase reactions, such as reductions and “click reactions” [14], is well known, as is its use in full CD derivatization in combination with MW irradiation

New metathesis catalyst bearing chromanyl moieties at the N-heterocyclic carbene ligand

• Agnieszka Hryniewicka,
• Szymon Suchodolski,
• Agnieszka Wojtkielewicz,
• Jacek W. Morzycki and
• Stanisław Witkowski

Beilstein J. Org. Chem. 2015, 11, 2795–2804, doi:10.3762/bjoc.11.300

• modified stereoselective catalysts were described [5][6][7][8]. Over the last few years, considerable attention has also been paid to immobilisation and tagging of catalysts and especially on making them more environmentally friendly [9][10][11][12][13][14]. Alkene cross-metathesis (CM) is a convenient

Dicarboxylic esters: Useful tools for the biocatalyzed synthesis of hybrid compounds and polymers

• Ivan Bassanini,
• Karl Hult and
• Sergio Riva

Beilstein J. Org. Chem. 2015, 11, 1583–1595, doi:10.3762/bjoc.11.174

• for example Zang et al. [49], Kobayashi and Makino [50], Gross et al. [51]). Nowadays lipases are not only used to achieve simple polycondensation reactions, but are exploited due to their chemo-, stereo- and enantioselectivity. In addition, they are seen as environmentally friendly alternative to

Preparative semiconductor photoredox catalysis: An emerging theme in organic synthesis

• David W. Manley and
• John C. Walton

Beilstein J. Org. Chem. 2015, 11, 1570–1582, doi:10.3762/bjoc.11.173

• ; organic synthesis; photocatalysis; titania; Introduction Synthetic chemistry is the springboard into innovative new products and materials for improving the wellbeing of society. In this context discovering cleaner, greener, more environmentally friendly preparative chemical methods has grown to an

Properties of PTFE tape as a semipermeable membrane in fluorous reactions

• Brendon A. Parsons,
• Olivia Lin Smith,
• Myeong Chae and
• Veljko Dragojlovic

Beilstein J. Org. Chem. 2015, 11, 980–993, doi:10.3762/bjoc.11.110

• substrate through the PTFE tape the product also formed in the delivery tube. The PV-PTFE method is inexpensive, simple to use and more environmentally friendly. Furthermore, the delivery of the reagent can easily be stopped and the reaction products are easy to recover. PV-PTFE reactions have no

Eosin Y-catalyzed visible-light-mediated aerobic oxidative cyclization of N,N-dimethylanilines with maleimides

• Zhongwei Liang,
• Song Xu,
• Wenyan Tian and
• Ronghua Zhang

Beilstein J. Org. Chem. 2015, 11, 425–430, doi:10.3762/bjoc.11.48

• and not sustainable. Similar to the redox properties of these organometallic complexes, some metal-free organic dyes such as Eosin Y, Rose Bengal, Fluorescein, and Methylene Blue, have shown superiority of their applications as photocatalysts, which are easy to handle, environmentally friendly

• presented the same reaction using [Ru(bpy)3]3+ as photoredox catalyst under irradiation with visible light next year [44]. Herein, we show an environmentally friendly aerobic oxidative cyclization methodology that avoids the use of metal catalysts and makes full use of air as oxidant. Results and Discussion

Matsuda–Heck reaction with arenediazonium tosylates in water

• Ksenia V. Kutonova,
• Marina E. Trusova,
• Andrey V. Stankevich,
• Pavel S. Postnikov and
• Victor D. Filimonov

Beilstein J. Org. Chem. 2015, 11, 358–362, doi:10.3762/bjoc.11.41

• Chemistry of New Materials NAS Belarus, 220141, Minsk, Belarus Department of General and Inorganic Chemistry, National Research Tomsk Polytechnic University, 634050 Tomsk, Russia 10.3762/bjoc.11.41 Abstract An environmentally friendly Matsuda–Heck reaction with arenediazonium tosylates has been developed

• ]. In this work, we present a fast, environmentally friendly, low palladium loading method of the Matsuda–Heck arylation of the different alkenes with ADT in water under microwave irradiation. Results and Discussion Our preliminary study was dedicated to the optimization of the alkene arylation

The Shono-type electroorganic oxidation of unfunctionalised amides. Carbon–carbon bond formation via electrogenerated N-acyliminium ions

• Alan M. Jones and
• Craig E. Banks

Beilstein J. Org. Chem. 2014, 10, 3056–3072, doi:10.3762/bjoc.10.323

• having the nucleophile solid-supported [53]. The use of ionic liquids as a green electrolyte/solvent [54] and using solar power to provide the electrical current [55] are some of the recent additions to make electrosynthesis even more environmentally friendly. Further advances have been made using

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

• chiral drugs has emerged as an important factor in efficacy and safety of their application [1][2][3]. Thus, the development of an effective, inexpensive and environmentally friendly method for the formulation of single enantiomers still remains a challenging task for organic chemists. Nowadays

Come-back of phenanthridine and phenanthridinium derivatives in the 21st century

• Lidija-Marija Tumir,
• Marijana Radić Stojković and
• Ivo Piantanida

Beilstein J. Org. Chem. 2014, 10, 2930–2954, doi:10.3762/bjoc.10.312

• (52–99%, Scheme 5). Important advantages of the method are environmentally friendly and easily removable byproducts (CO2 and ethanol or phenol), and the negligible impact of the electronic nature of the substituent on the reaction [18]. The oxidative PhI(OAc)2-mediated cyclization of 2

• -substituted on the phenyl side-rings by a large variety of substituents, as well as stereo- and regioselectivity (particularly for the bulky groups). Nevertheless, due to the most common metal catalyst (palladium) this method is significantly more expensive and less environmentally friendly than radical-based

• methods. To address these disadvantages, in the last decade particular attention was given to the replacement of the expensive palladium catalyst, for instance by iron [37]. However, major impact was made by introduction of the cheap and environmentally friendly intramolecular homolytic aromatic

Recent advances in the electrochemical construction of heterocycles

• Robert Francke

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

• considered to be a safe and environmentally friendly methodology [21][22][23][24][25]. A further interesting feature is that electrochemical reactions are feasible under very mild conditions; since the reaction rate is determined by the electrode potential, reactions with high activation energies can be

A green approach to the synthesis of novel phytosphingolipidyl β-cyclodextrin designed to interact with membranes

• Yong Miao,
• Florence Djedaïni-Pilard and
• Véronique Bonnet

Beilstein J. Org. Chem. 2014, 10, 2654–2657, doi:10.3762/bjoc.10.278

• using a green methodology. Reactions using greener and safer catalysts with more environmentally friendly purification solvents were performed. Four unreported mono-substituted cyclodextrins bearing a phytosphingolipidyl chain and a fatty acid chain (C10, C12, C14 and C18) were successfully obtained

• time in cyclodextrin chemistry via solvent-free substitution of aminocyclodextrin followed by the use of a new, more environmentally friendly peptide coupling agent known as COMU (1-cyano-2-ethoxy-2-oxoethylidenaminooxy)dimethylaminomorpholinocarbenium hexafluorophosphate). Finally, by optimized

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

• promising technology for environmentally friendly chemical processes [26]. The electroreduction of CO2 can be applied for the synthesis of fuels like formic acid [27], methanol [28] or methane [29] via two-, six- and eight-electron reductions, respectively (Scheme 2). This way electric energy from periodic

• compounds that are valuable. This way a combined electrochemical yield, i.e., the fraction of supplied current going to the desired reaction, is achieved, reducing energy consumption and reaction time. This methodology is very environmentally friendly since there is no generation of toxic wastes, electrical

• [41][42]. Hydrogen formation can be limited by usage of cathode materials with high hydrogen overvoltage like lead and mercury, or more environmentally friendly tantalum and zinc [43]. In order to minimize other side reactions a cation exchange membrane (CEM) is necessary, allowing different

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

• radiation; Introduction The growing demand for the application of environmentally friendly technologies has led, in the last decades, to a great deal of research effort to develop low-impact alternative synthetic methods as well as to replace toxic and harmful solvents by more environmentally benign ones

Pd/C-catalyzed aerobic oxidative esterification of alcohols and aldehydes: a highly efficient microwave-assisted green protocol

• Marina Caporaso,
• Giancarlo Cravotto,
• Spyros Georgakopoulos,
• George Heropoulos,
• Katia Martina and
• Silvia Tagliapietra

Beilstein J. Org. Chem. 2014, 10, 1454–1461, doi:10.3762/bjoc.10.149

• on the catalytic performance of Au [21][22][23][24][25][26], Ru [27][28][29], Ir [30] and Pd [31][32][33][34][35]. Moreover, the search for new, less expensive and environmentally friendly catalysts has attracted a great deal of interest because of the limited availability and high price of noble

• interfaces and surfaces NIS, University of Turin, Via P. Giuria 7–9, 10125 Torino, Italy Institute of Biology, Medicinal Chemistry and Biotechnology, National Hellenic Research Foundation, 48. Vas. Constantinou Ave., 11635 Athens, Greece 10.3762/bjoc.10.149 Abstract We herein describe an environmentally

• friendly microwave-assisted oxidative esterification of alcohols and aldehydes in the presence of molecular oxygen and a heterogeneous catalysis (Pd/C, 5 mol %). This efficient and ligandless conversion procedure does not require the addition of an organic hydrogen acceptor. The reaction rate is strongly

Synthesis of chiral N-phosphoryl aziridines through enantioselective aziridination of alkenes with phosphoryl azide via Co(II)-based metalloradical catalysis

• Jingran Tao,
• Li-Mei Jin and
• X. Peter Zhang

Beilstein J. Org. Chem. 2014, 10, 1282–1289, doi:10.3762/bjoc.10.129

• -containing aziridines, producing nitrogen gas as the only and also environmentally friendly byproduct. Chiral phosphorylated aziridines and their derivatives have been demonstrated with pharmaceutical and other important synthetic applications. In addition to the fundamental and practical significance of the

Visible-light photoredox catalyzed synthesis of pyrroloisoquinolines via organocatalytic oxidation/[3 + 2] cycloaddition/oxidative aromatization reaction cascade with Rose Bengal

• Carlos Vila,
• Jonathan Lau and
• Magnus Rueping

Beilstein J. Org. Chem. 2014, 10, 1233–1238, doi:10.3762/bjoc.10.122

• have very important qualities such as being inexpensive, environmentally friendly and easy to handle. As a part of our ongoing research on photoredox catalysis [62][63][64][65][66][67][68][69][70][71][72], we herein present a synthesis of pyrrolo[2,1-a]isoquinolines through an oxidation/[3+2

Asymmetric total synthesis of a putative sex pheromone component from the parasitoid wasp Trichogramma turkestanica

• Danny Geerdink,
• Jeffrey Buter,
• Teris A. van Beek and
• Adriaan J. Minnaard

Beilstein J. Org. Chem. 2014, 10, 761–766, doi:10.3762/bjoc.10.71

• reason to study these tiny wasps is their possible application in an environmentally friendly way of crop protection [5]. After copulation, the female wasp deposits the fertilized eggs inside the eggs of a host insect, which is used as a food source for the hatched wasps. Biological studies have revealed

Integration of enabling methods for the automated flow preparation of piperazine-2-carboxamide

• Richard J. Ingham,
• Claudio Battilocchio,
• Joel M. Hawkins and
• Steven V. Ley

Beilstein J. Org. Chem. 2014, 10, 641–652, doi:10.3762/bjoc.10.56

• via a number of different approaches but the most environmentally friendly procedure is the hydration of nitriles [19]. Although this is generally considered to be a simple transformation, there are some inherent problems with the standard techniques of hydrolysis [20]. Further to our previous work

Visible-light photoredox catalysis enabled bromination of phenols and alkenes

• Yating Zhao,
• Zhe Li,
• Chao Yang,
• Run Lin and
• Wujiong Xia

Beilstein J. Org. Chem. 2014, 10, 622–627, doi:10.3762/bjoc.10.53

• several drawbacks such as toxic reagents, harsh conditions, low yields, and low chemo- and regioselectivity. Hence, the development of an environmentally friendly methodology for the bromination of phenols with high chemoselectivity under mild and operationally simple conditions is still appealing

Silica: An efficient catalyst for one-pot regioselective synthesis of dithioethers

• Samir Kundu,
• Babli Roy and
• Basudeb Basu

Beilstein J. Org. Chem. 2014, 10, 26–33, doi:10.3762/bjoc.10.5

• environmentally friendly and sustainable [32][33][34][35][36]. Mesoporous inorganic oxides, which often facilitate various organic reactions, are considered suitable to promote eco-friendly chemical processes [36]. Organic reactions with a high selectivity under eco-friendly and sustainable conditions are

Continuous-flow Heck synthesis of 4-methoxybiphenyl and methyl 4-methoxycinnamate in supercritical carbon dioxide expanded solvent solutions

• Phei Li Lau,
• Ray W. K. Allen and
• Peter Styring

Beilstein J. Org. Chem. 2013, 9, 2886–2897, doi:10.3762/bjoc.9.325

• biphasic mode using a mixture of solvents, such as ethylene glycol and toluene [8]. The drive to carry out reactions in environmentally benign media also led to studies being carried out in “green” (environmentally friendly) solvents, such as aqueous media, some supercritical fluids (SCFs), ionic liquids