New palladium–oxazoline complexes: Synthesis and evaluation of the optical properties and the catalytic power during the oxidation of textile dyes

• Rym Hassani,
• Mahjoub Jabli,
• Yakdhane Kacem,
• Jérôme Marrot,
• Damien Prim and
• Béchir Ben Hassine

Beilstein J. Org. Chem. 2015, 11, 1175–1186, doi:10.3762/bjoc.11.132

• versus temperature. Recycling experiments for Erio removal (C0 = 30 ppm, 20 mL) in the presence of catalyst 9 at pH 7 and T = 22 °C. Cyclopalladation reactions of (S)-4-isopropyl-2-(naphthalen-1-yl)oxazoline. Synthesis of cyclopalladated complex from bis-oxazoline. Synthesis of the bis(oxazoline

Chiroptical properties of 1,3-diphenylallene-anchored tetrathiafulvalene and its polymer synthesis

• Masashi Hasegawa,
• Junta Endo,
• Seiya Iwata,
• Toshiaki Shimasaki and
• Yasuhiro Mazaki

Beilstein J. Org. Chem. 2015, 11, 972–979, doi:10.3762/bjoc.11.109

• of the C=C=C unit at 1914 cm−1. Because new symmetrical allenes were subject to optical resolution, the separation of (rac)-3 was carried out by using a recycling HPLC method on a chiral stationary phase (DAICEL Chiralpak IA-3) with hexane/CHCl3/EtOH (v/v = 20:10:0.2) elution. Thus, equimolecular

Multivalent polyglycerol supported imidazolidin-4-one organocatalysts for enantioselective Friedel–Crafts alkylations

• Tommaso Pecchioli,
• Manoj Kumar Muthyala,
• Rainer Haag and
• Mathias Christmann

Beilstein J. Org. Chem. 2015, 11, 730–738, doi:10.3762/bjoc.11.83

• catalysts, finally, recycling of the polymer was studied. Heterogeneous catalysis allowed for simple separations of the immobilized species from the reaction media. Indeed, working under homogeneous conditions did not enable separation by simple filtration. On the other hand, the multivalent catalysts 4a

• elucidate the reason of the decreased reactivity and analysis of the recovered polymer by 1H NMR indicated the leakage of the imidazolidin-4-one moiety. Nevertheless, studies focussing on improved catalyst stability and recycling are in progress. Conclusion In summary, we have successfully employed a CuAAC

• offer opportunities for further studies. One of the advantages of the multivalent catalyst 4b was demonstrated to be its easy separability from the reaction media and its reuse for three consecutive times, whereas further investigations will be necessary on recycling of the polymeric support. Synthesis

Photovoltaic-driven organic electrosynthesis and efforts toward more sustainable oxidation reactions

• Bichlien H. Nguyen,
• Robert J. Perkins,
• Jake A. Smith and
• Kevin D. Moeller

Beilstein J. Org. Chem. 2015, 11, 280–287, doi:10.3762/bjoc.11.32

• cathode. For all of the oxidation reactions highlighted in this work, this reduction reaction leads to the formation of hydrogen gas. In addition to the direct oxidation of a substrate described in the preceding paragraph, indirect electrochemical methods also offer a powerful means of recycling chemical

• reason, the sunlight-driven oxidation reactions were extended to the recycling of chemical oxidants. Three examples are shown in Scheme 4 [12] where each was chosen for its unique feature related to the indirect electrochemical approach. In the first reaction (Scheme 4a), an asymmetric dihydroxylation

• with K2OsO2(OH)4 and hydroquinidine 1,4-phthalazinediyl diether ((DHQD)2PHAL) was performed in a catalytic fashion by recycling the ferricyanide cooxidant at the anode [19]. In this case, the use of the chemical oxidation strategy allows for incorporation of an asymmetry-inducing element into the

Synthetic strategies for the fluorescent labeling of epichlorohydrin-branched cyclodextrin polymers

• Milo Malanga,
• Mihály Bálint,
• István Puskás,
• Kata Tuza,
• Tamás Sohajda,
• László Jicsinszky,
• Lajos Szente and
• Éva Fenyvesi

Beilstein J. Org. Chem. 2014, 10, 3007–3018, doi:10.3762/bjoc.10.319

• that has contact with water, or when CD is to be used for the removal of specific component(s) of a water-based process. In addition, free CDs are more difficult to recover for commercial recycling. A solution to these challenges is encoded in polymeric cyclodextrin structures. The cyclodextrins fixed

An integrated photocatalytic/enzymatic system for the reduction of CO₂ to methanol in bioglycerol–water

• Michele Aresta,
• Angela Dibenedetto,
• Tomasz Baran,
• Antonella Angelini,
• Przemysław Łabuz and
• Wojciech Macyk

Beilstein J. Org. Chem. 2014, 10, 2556–2565, doi:10.3762/bjoc.10.267

• . Keywords: CO2 chemistry; electron transfer; enzymatic CO2 reduction; NADH regeneration; photochemistry; photosensitization; Introduction The reduction of CO2 to fuel is a technology that could contribute to the recycling of large quantities of carbon. Among the various routes, the enzymatic reduction of

• reduction of NAD+ using bioglycerol as a H-donor and a Rh(III)-complex as an e−–H+ transfer agent were found. It was shown that the photocatalyst, the electron mediator and the H-donor have suitable energy levels that can be combined together for an effective recycling of NAD+. The cofactor can be used

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

• ; counter electrode reaction; electrocarboxylation mechanism; reactor setup; Introduction Carbon dioxide recycling Implementing sustainable, resource-efficient chemical processes to meet the world’s growing demand for energy and chemicals is one of today’s major challenges. Depletion of fossil resources

Visible light photoredox-catalyzed deoxygenation of alcohols

• Daniel Rackl,
• Viktor Kais,
• Peter Kreitmeier and
• Oliver Reiser

Beilstein J. Org. Chem. 2014, 10, 2157–2165, doi:10.3762/bjoc.10.223

• triphenylphosphine to triphenylphospine oxide and iodine to iodide, are required, which appears to be problematic for establishing a sustainable protocol that allows the recycling and reuse of the reagents involved. Herein we report a redox economic deoxygenation method of alcohols in which formation of radicals is

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

• –MS was the butyl butyrate. Esterification reactions using other linear alcohols as substrate, such as pentanol and hexadecanol carried out in methanol, gave in both cases less than 10% yield of the corresponding esters (data not shown). The recycling of the catalyst was evaluated in order to better

• preliminary evaluation of catalyst recycling showed that Pd/C can be reused for the esterification of benzaldehyde after hydrogenation. Experimental General methods All commercially available reagents and solvents were used without further purification. Pd sources from Sigma-Aldrich included 10 wt % Pd/C (Cat

Rasta resin–triphenylphosphine oxides and their use as recyclable heterogeneous reagent precursors in halogenation reactions

• Xuanshu Xia and
• Patrick H. Toy

Beilstein J. Org. Chem. 2014, 10, 1397–1405, doi:10.3762/bjoc.10.143

• . Synthesis and applications of rasta resins 16 and 17a,b. Synthesis of bifuncitonal rasta resin 18. Appel reactions using 16.a Halogenation reactions of aldehydes using 16.a Halogenation reactions of aziridines using 16.a Recycling of 16 in the chlorination of 4H.a Recycling of 16 in the chlorination of 8B.a

• Halogenation reactions of epoxides using 18.a Recycling of 18 in the chlorination of 10c.a Supporting Information Supporting Information File 40: Additional experimental details and characterization data of synthesized compounds. Acknowledgements This research was supported financially by the University of

Amino acid motifs in natural products: synthesis of O-acylated derivatives of (2S,3S)-3-hydroxyleucine

• Oliver Ries,
• Martin Büschleb,
• Markus Granitzka,
• Dietmar Stalke and
• Christian Ducho

Beilstein J. Org. Chem. 2014, 10, 1135–1142, doi:10.3762/bjoc.10.113

• reaction would suppress the reformation of alcohol 3 as the competing Grignard reduction product, as it had been claimed by Zhu and co-workers in their initial report [32]. It was therefore decided to attempt the recycling of alcohol 3, which was obtained in varying amounts, for another round of oxidation

• of these results, we desisted from the use of this alcohol in a third oxidation–addition cycle. It was concluded that the recycling of the Grignard reduction product is in principle feasible, but that one should always check its enantiomeric purity prior to a repetition of the oxidation–addition

Preparation of phosphines through C–P bond formation

• Iris Wauters,
• Wouter Debrouwer and
• Christian V. Stevens

Beilstein J. Org. Chem. 2014, 10, 1064–1096, doi:10.3762/bjoc.10.106

• obtained was 45%. The same group has shown that imidazolium based ionic liquids can be used as a medium to perform the C–P cross-coupling reactions. This method allows an easy separation of the product from the catalyst and the recycling of the palladium catalyst [176]. Stelzer and co-workers have

The influence of intraannular templates on the liquid crystallinity of shape-persistent macrocycles

• Joscha Vollmeyer,
• Ute Baumeister and
• Sigurd Höger

Beilstein J. Org. Chem. 2014, 10, 910–920, doi:10.3762/bjoc.10.89

• only few oligomeric byproducts are formed (Figure 2). With the aid of recycling GPC (recGPC) these impurities could be removed and 1a is obtained in 49% yield. Following this synthetic route we synthesized the macrocycles 1a–c as well as the macrocycles 3a and 4a with different side chains (Figure 1

Clean and fast cross-coupling of aryl halides in one-pot

• Valerica Pandarus,
• Geneviève Gingras,
• François Béland,
• Rosaria Ciriminna and
• Mario Pagliaro

Beilstein J. Org. Chem. 2014, 10, 897–901, doi:10.3762/bjoc.10.87

• shown elsewhere [10], wherein the issue of catalyst recycling is also addressed in detail. Now we report a new method that establishes a direct route, in one-pot, to unsymmetrically coupled biaryls starting from two different aryl bromides and bis(pinacolato)diboron without the need to isolate the

Columnar/herringbone dual crystal packing of pyrenylsumanene and its photophysical properties

• Binod Babu Shrestha,
• Shuhei Higashibayashi and
• Hidehiro Sakurai

Beilstein J. Org. Chem. 2014, 10, 841–847, doi:10.3762/bjoc.10.80

• (1H NMR: CDCl3 7.24 ppm; 13C NMR: CDCl3 77.00 ppm). Elemental analyses were measured on a J-Science Micro corder JM10. Mass spectra were measured on a JEOL JMS-777V spectrometer using electron impact mode (EI). Gel-permeation chromatography (GPC) was performed on JAIGEL 1H and 2H using a JAI Recycling

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

• packed beds facilitates recycling of the catalyst, providing a further cost advantage. Interestingly, we have now found that no activation of the zirconia is needed (this is the same as for nitrile hydrations with manganese dioxide, but unlike the use of zirconia as a heterogeneous catalyst for Meerwein

Continuous flow nitration in miniaturized devices

• Amol A. Kulkarni

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

• . While the reaction occurs at high temperature (380–450 °C), the quenching was performed by hydrolysis as well as by rapid cooling of the diluted reaction mixture. The term per-pass conversion is used when the unreacted reactant is recycled back to the inlet. If no such recycling is carried out, the per

Practical synthesis of aryl-2-methyl-3-butyn-2-ols from aryl bromides via conventional and decarboxylative copper-free Sonogashira coupling reactions

• Andrea Caporale,
• Stefano Tartaggia,
• Andrea Castellin and
• Ottorino De Lucchi

Beilstein J. Org. Chem. 2014, 10, 384–393, doi:10.3762/bjoc.10.36

• complicates the recycling of the palladium catalyst since the two metals are difficult to separate. Sonogashira reactions can be used for the syntheses of terminal alkynes from aryl halides through the coupling with an alkyne source such as trimethylsilylacetylene (TMSA) or 2-methyl-3-butyn-2-ol (4) in

Secondary amine-initiated three-component synthesis of 3,4-dihydropyrimidinones and thiones involving alkynes, aldehydes and thiourea/urea

• Jie-Ping Wan,
• Yunfang Lin,
• Kaikai Hu and
• Yunyun Liu

Beilstein J. Org. Chem. 2014, 10, 287–292, doi:10.3762/bjoc.10.25

• of iminium ion 8. Finally, an intramolecular cyclization of 8 leads to the formation of 9 which subsequently undergoes deaminative elimination to result product 5 by releasing the amine catalyst for further recycling (Scheme 3). Conclusion In conclusion, we have established an unprecedented amine

Cyclic phosphonium ionic liquids

• Sharon I. Lall-Ramnarine,
• Joshua A. Mukhlall,
• James F. Wishart,
• Robert R. Engel,
• Alicia R. Romeo,
• Masao Gohdo,
• Sharon Ramati,
• Marc Berman and
• Sophia N. Suarez

Beilstein J. Org. Chem. 2014, 10, 271–275, doi:10.3762/bjoc.10.22

• would be exposed to extreme conditions, such as environmental exposure to high temperatures or exposure to extreme electromagnetic radiation (as in a dye-sensitized solar cell or ionizing radiation as in the recycling of spent nuclear fuel). ILs can play important roles in both of these latter areas [16

Biosynthesis of rare hexoses using microorganisms and related enzymes

• Zijie Li,
• Yahui Gao,
• Hideki Nakanishi,
• Xiaodong Gao and
• Li Cai

Beilstein J. Org. Chem. 2013, 9, 2434–2445, doi:10.3762/bjoc.9.281

• has the advantages of using cheaper catalysts without purification and the avoidance of cofactor recycling in vitro, while enzymatic conversion is more controllable and scalable. In addition, immobilized enzymes offer advantages over free and soluble enzymes in many aspects: 1) immobilized enzymes can

One-pot sequential synthesis of isocyanates and urea derivatives via a microwave-assisted Staudinger–aza-Wittig reaction

• Diego Carnaroglio,
• Katia Martina,
• Giovanni Palmisano,
• Andrea Penoni,
• Claudia Domini and
• Giancarlo Cravotto

Beilstein J. Org. Chem. 2013, 9, 2378–2386, doi:10.3762/bjoc.9.274

• -PPh2 has the advantage of a much easier reaction work-up [33][34][35][36][37][38]. A polymer regeneration procedure was described by Marsura et al. [35], however a quasi-stoichiometric amount makes the recycling step unneccessary. With the aim to overcome cost limitations we recently described the

Non-cross-linked polystyrene-supported 2-imidazolidinone chiral auxiliary: synthesis and application in asymmetric alkylation reactions

• Quynh Pham Bao Nguyen and
• Taek Hyeon Kim

Beilstein J. Org. Chem. 2013, 9, 2113–2119, doi:10.3762/bjoc.9.248

• -imidazolidinone chiral auxiliaries were successfully investigated with excellent diastereocontrol (>99% de). The recovery and the recycling of this soluble polymer-supported chiral auxiliary were achieved in order to produce highly optical pure carboxylic acids. Keywords: asymmetric alkylation; chiral

• auxiliaries; chiral carboxylic acids; 2-imidazolidinone; non-cross-linked polystyrene; Introduction Chiral auxiliaries have been proven as a powerful tool for the asymmetric synthesis of highly optical pure compounds used in pharmaceuticals or agrochemicals [1][2]. The recycling and reuse of expensive chiral

• for asymmetric synthesis, into the solid support [18][19]. As a part of our ongoing research, we herein report a novel NCPS-supported 2-imidazolidinone chiral auxiliary that exhibited excellent diastereocontrol. Its recycling and reuse for the synthesis of several chiral carboxylic acids are addressed

One-step synthesis of pyridines and dihydropyridines in a continuous flow microwave reactor

• Mark C. Bagley,
• Vincenzo Fusillo,
• Robert L. Jenkins,
• M. Caterina Lubinu and
• Christopher Mason

Beilstein J. Org. Chem. 2013, 9, 1957–1968, doi:10.3762/bjoc.9.232

• by Kappe, Kunz and Kirschning revealed that continuous flow processing gave better conversions and improved catalyst recycling, with no loss of activity [26]. A range of other applications have been explored, from a continuous flow isothermal narrow channel microreactor for process intensification of

The application of a monolithic triphenylphosphine reagent for conducting Ramirez gem-dibromoolefination reactions in flow

• Kimberley A. Roper,
• Malcolm B. Berry and
• Steven V. Ley

Beilstein J. Org. Chem. 2013, 9, 1781–1790, doi:10.3762/bjoc.9.207

• 0 °C, however the allyl alcohol (Table 3, entry 3) required recycling through the monolith to effect complete conversion. In batch, this reaction required low temperature conditions (−78 °C) and the presence of base to give an isolated yield of 78% [62], however this could be improved to 90% by