New bio-nanocomposites based on iron oxides and polysaccharides applied to oxidation and alkylation reactions

• Daily Rodríguez-Padrón,
• Alina M. Balu,
• Antonio A. Romero and
• Rafael Luque

Beilstein J. Org. Chem. 2017, 13, 1982–1993, doi:10.3762/bjoc.13.194

• potential from an environmental point-of-view since it is able to reduce solvent issues in chemical syntheses. The catalytic activity of the obtained nanocatalysts was investigated in both the oxidation of benzyl alcohol to benzaldehyde and in the alkylation of toluene with benzyl chloride. The microwave

• -assisted oxidation of benzyl alcohol reached 45% conversion after 10 min. The conversion of the alkylation of toluene in both microwave-assisted and conventional heating methods was higher than 99% after 3 min and 30 min, respectively. The transformation of benzyl alcohol and toluene into valuable product

• in both the oxidation and alkylation reaction reveals a potential method for the valorization of lignocellulosic biomass. Keywords: alkylation; benzyl alcohol; benzyl chloride; iron oxide; mechanochemistry; microwave-assisted oxidation; polysaccharide; toluene; Introduction Heterogeneous catalysis

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

• ][75][76]. In view of this, chemists have introduced alternative energy sources like, microwave, sonication, mechanomilling, etc. [12][27][77]. Su and co-workers reported a copper-catalyzed arylation of anilines using arylboronic acid under high speed ball-milling conditions. Using 1.0 equiv of Cu(OAc

• reaction medium, solvent-free synthesis, microwave synthesis, use of different Lewis acids FeCl3, NiCl2, BiCl3, InBr3, use of Brønsted acids PTSA, etc. are also reported [129][130]. Recently, Mal and co-workers reported a mechanochemical Biginelli reaction by a subcomponent synthesis approach [131][132

A novel application of 2-silylated 1,3-dithiolanes for the synthesis of aryl/hetaryl-substituted ethenes and dibenzofulvenes

• Grzegorz Mlostoń,
• Paulina Pipiak,
• Róża Hamera-Fałdyga and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 1900–1906, doi:10.3762/bjoc.13.185

• with a FTIR NEXUS spectrometer (as film or KBr pellets). High resolution MS measurements were performed with a GCT Premier Waters instrument. Melting points were determined in capillaries with a Stuart SMP30 apparatus with automatic temperature monitoring. Microwave-supported syntheses of thioketones 1

• were performed using the CEM-focused Microwave-type Discover SPD reactor. Starting materials: Trimethylsilyldiazomethane (TMS-CHN2) was a commercial reagent which was used in all reactions as 1 M THF solution without further purification. Thiobenzophenone (1a), thiodibenzosuberenone (1h), and

Mechanochemical synthesis of thioureas, ureas and guanidines

• Vjekoslav Štrukil

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

• -methoxyphenyl isothiocyanate, which required 45 minutes of manual grinding and 15 or 45 minutes of milling, due to its diminished electrophilicity. In the context of these results, it is reasonable to assume that the solvent-free microwave synthesis of diarylthioureas described by Li et al. actually proceeded

• in the solid-state before having been exposed to microwave irradiation for 1.5–4.5 minutes. In their paper, the authors state: "Aryl isothiocyanate (1 mmol) and aromatic primary amine (1 mmol) were mixed thoroughly in an agate mortar" [33]. Considering the established reactivity pattern of electron

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

• the environment could be achieved by the minimization of waste produced in the process, the employment of the more efficient reagents and catalysts and by the application of microwave [2], photochemical [3] or high pressure conditions [4], thus reducing reaction time and energy consumption. In recent

• considered for LAG in mechanosynthesis. A comparison of results with literature values demonstrates the benefits of mechanosynthesis. For instance, alkylation of theobromine (14) [34] in a microwave reactor in solution gives two side-products, an O-alkylated and a uracil ring-opened product (induced by base

An efficient Pd–NHC catalyst system in situ generated from Na₂PdCl₄ and PEG-functionalized imidazolium salts for Mizoroki–Heck reactions in water

• Nan Sun,
• Meng Chen,
• Liqun Jin,
• Wei Zhao,
• Baoxiang Hu,
• Zhenlu Shen and
• Xinquan Hu

Beilstein J. Org. Chem. 2017, 13, 1735–1744, doi:10.3762/bjoc.13.168

• media became more and more attractive [11]. Despite there are several strategies for palladium-catalyzed cross-coupling reactions in water, such as microwave heating [12], ultrasonic irradiation [13][14] and ligand-free methodology [15][16], the more efficient and preferable one is the use of water

An effective Pd nanocatalyst in aqueous media: stilbene synthesis by Mizoroki–Heck coupling reaction under microwave irradiation

• Carolina S. García,
• Paula M. Uberman and
• Sandra E. Martín

Beilstein J. Org. Chem. 2017, 13, 1717–1727, doi:10.3762/bjoc.13.166

• Mizoroki–Heck coupling reactions under microwave irradiation (MW) were carried out with a colloidal Pd nanocatalyst stabilized with poly(N-vinylpyrrolidone) (PVP). Many stilbenes and novel heterostilbenes were achieved in good to excellent yields starting from aryl bromides and different olefins. The

• particular, Pd NPs have been well-established as catalysts in the Mizoroki–Heck coupling reaction, obtaining the desired products in good to high yields, finding some examples in aqueous solution and under microwave (MW) irradiation [26][27][28][29][30][31][32][33][34][35][36]. Besides these studies, there

• QP 5050 spectrometer equipped with a VF-5 ms, 30 m × 0.25 mm × 0.25 μm column. Melting points were determined with an electrical instrument. MW-induced reactions were performed in a CEM Focused Microwave TM Synthesis System, Model Discover single mode instrument. Transmission electron microscopy was

Block copolymers from ionic liquids for the preparation of thin carbonaceous shells

• Sadaf Hanif,
• Bernd Oschmann,
• Dmitri Spetter,
• Muhammad Nawaz Tahir,
• Wolfgang Tremel and
• Rudolf Zentel

Beilstein J. Org. Chem. 2017, 13, 1693–1701, doi:10.3762/bjoc.13.163

• are applied as catalytic membranes, thermotropic liquid crystals [12], polymer electrolytes, ionic conductive materials, CO2 absorbing materials, microwave absorbing materials and porous materials [4]. Most of these polymers were synthesized by free radical polymerization. There are just few reports

Oxidative dehydrogenation of C–C and C–N bonds: A convenient approach to access diverse (dihydro)heteroaromatic compounds

• Santanu Hati,
• Ulrike Holzgrabe and
• Subhabrata Sen

Beilstein J. Org. Chem. 2017, 13, 1670–1692, doi:10.3762/bjoc.13.162

• facilitate the conversion [52][53][54][55]. Unfortunately most of these methods suffer from the disadvantages of prolonged reaction time, poor yield and competing oxidative dealkylation of 4-benzyl and sec-alkyl-substituted DHP substrates. Alternative strategies involving transition metals and microwave

• heating, ultrasonication and solvent-free conditions alleviated the drawbacks to a major extent [56][57][58][59][60][61]. One such useful strategy include manganese dioxide (MnO2)-mediated oxidative aromatization of 1,4-DHP 45 to afford substituted pyridine derivatives 46 under microwave conditions

• K-10 and Pd/C as catalysts. The microwave-assisted synthesis of β-carboline 96 from tetrahydro-β-carboline 95 using catalytic Pd/C and lithium carbonate at high temperature is also reported [96]. This high yielding procedure gets completed within a few minutes (Scheme 36). Although the reaction

The chemistry and biology of mycolactones

• Matthias Gehringer and
• Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

Synthesis and metal binding properties of N-alkylcarboxyspiropyrans

• Alexis Perry and
• Christina J. Kousseff

Beilstein J. Org. Chem. 2017, 13, 1542–1550, doi:10.3762/bjoc.13.154

• , robust conditions. Reported protocols have employed chloroform [3], acetonitrile [19], acetone [20], nitromethane [21], 1,2-dichlorobenzene [22], toluene [23], reaction in the absence of solvent [24] or use of microwave irradiation [25]. We found that refluxing acetonitrile was relatively effective, if

Development of a method for the synthesis of 2,4,5-trisubstituted oxazoles composed of carboxylic acid, amino acid, and boronic acid

• Kohei Yamada,
• Naoto Kamimura and
• Munetaka Kunishima

Beilstein J. Org. Chem. 2017, 13, 1478–1485, doi:10.3762/bjoc.13.146

• temperature to 80 °C or increasing to 160 °C by microwave irradiation were not effective for improving the reaction (Table 2, entries 16 and 17). Consequently, we found that the reaction shown in entry 4 afforded the optimal result (see Table S1 in Supporting Information File 1 for further manipulation of the

Syntheses of 3,4- and 1,4-dihydroquinazolines from 2-aminobenzylamine

• Jimena E. Díaz,
• Silvia Ranieri,
• Nadia Gruber and
• Liliana R. Orelli

Beilstein J. Org. Chem. 2017, 13, 1470–1477, doi:10.3762/bjoc.13.145

• required functionalization of both amino groups present in 2-ABA was achieved by different routes involving selective N-acylation and cesium carbonate-mediated N-alkylation reactions, avoiding protection/deprotection steps. The heterocycles were efficiently synthesized in short reaction times by microwave

• transformations like conversion of amides into nitriles [52][53] or the Beckmann rearrangement [52][54]. They have also been widely employed in heterocyclic synthesis, including microwave-assisted reactions. The recognized wide functional group tolerance, stability and low environmental impact are additional

• advantages of these reagents. Cyclocondensation is a fundamental tool in heterocycles synthesis, and microwave (MW) heating has found interesting applications in this area [55][56], overcoming limitations arising from low reactivity and side reactions typical of conventional heating [57]. We had previously

1-Imidoalkylphosphonium salts with modulated C_α–P⁺ bond strength: synthesis and application as new active α-imidoalkylating agents

• Jakub Adamek,
• Roman Mazurkiewicz,
• Anna Węgrzyk and
• Karol Erfurt

Beilstein J. Org. Chem. 2017, 13, 1446–1455, doi:10.3762/bjoc.13.142

• arenes can be markedly facilitated using 1-imidoalkylphosphonium salts derived from triarylphosphines with electron-withdrawing substituents such as tris(m-chorophenyl)phosphine, tris(p-chlorophenyl)phosphine and tris[p-(trifluoromethyl)phenyl]phosphine. Microwave irradiation also considerably

• phosphonium salts (Table 3). The reaction of 1-phthalimidoethyltriphenylphosphonium tetrafluoroborate (5b) with anisole required a relatively high temperature (180 °C; Table 3, entry 1). The reaction temperature could be reduced considerably to 150 °C together with a reduced reaction time using microwave

• -phthalimidoethyltriphenylphosphonium salt 5b (cf Table 3, entries 1 against 12 and 16 against 21). As expected, the reaction of anisole with 1-phthalimido-1-phenylmethyltriphenylphosphonium salt 5f, which generates a more stable benzyl-type carbenium cation, started at a lower temperature (150 °C; Table 3, entry 8). Under microwave

A speedy route to sterically encumbered, benzene-fused derivatives of privileged, naturally occurring hexahydropyrrolo[1,2-b]isoquinoline

• Olga Bakulina,
• Alexander Ivanov,
• Vitalii Suslonov,
• Dmitry Dar’in and
• Mikhail Krasavin

Beilstein J. Org. Chem. 2017, 13, 1413–1424, doi:10.3762/bjoc.13.138

• with HPA either at rt or at reflux temperature in acetonitrile or toluene. Attempts to trigger the reaction with these substrates by excluding solvent altogether [34] or applying microwave irradiation (up to 2 h at 200 °C in MeCN) were also unsuccessful. Any appreciable conversion led to predominant

Detection of therapeutic radiation in three-dimensions

• John A. Adamovics

Beilstein J. Org. Chem. 2017, 13, 1325–1331, doi:10.3762/bjoc.13.129

• equivalent of aryl aldehyde is reacted with 2 equivalents of an electron-rich aromatic compound such as N,N-dimethylaniline [19] (Scheme 2). This reaction is usually carried out in the presence of various acids [16][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. Microwave radiation

BODIPY-based fluorescent liposomes with sesquiterpene lactone trilobolide

• Ludmila Škorpilová,
• Silvie Rimpelová,
• Michal Jurášek,
• Miloš Buděšínský,
• Jana Lokajová,
• Roman Effenberg,
• Petr Slepička,
• Tomáš Ruml,
• Eva Kmoníčková,
• Pavel B. Drašar and
• Zdeněk Wimmer

Beilstein J. Org. Chem. 2017, 13, 1316–1324, doi:10.3762/bjoc.13.128

• compound is shown in Scheme 1, part B. Propargyl-ChL [35] was introduced into Huisgen copper-catalyzed 1,3-dipolar cycloaddition [36] (CuAAC) with BODIPY 3. This microwave-assisted reaction catalyzed by CuSO4·5H2O, sodium ascorbate and a catalytic amount of TBTA (tris[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl

Synthesis of novel 13α-estrone derivatives by Sonogashira coupling as potential 17β-HSD1 inhibitors

• Ildikó Bacsa,
• Rebeka Jójárt,
• János Wölfling,
• Gyula Schneider,
• Bianka Edina Herman,
• Mihály Szécsi and
• Erzsébet Mernyák

Beilstein J. Org. Chem. 2017, 13, 1303–1309, doi:10.3762/bjoc.13.126

• 10.3762/bjoc.13.126 Abstract Novel 13α-estrone derivatives were synthesized by Sonogashira coupling. Transformations of 2- or 4-iodo regioisomers of 13α-estrone and its 3-methyl ether were carried out under different conditions in a microwave reactor. The 2-iodo isomers were reacted with para-substituted

• microwave reactor. 4-Phenylalkynyl regioisomers (10a, 11a) were obtained in high yields using 0.05 equiv of Pd(PPh3)2Cl2 and CuI in CH3CN or DMF, in the presence of Et3N as a base at 80 °C for 20 min in a microwave reactor. After establishing the most favorable reaction conditions, the Sonogashira reactions

• the modified procedure of Li et al. using Pd(OAc)2 or Pd(PPh3)2Cl2 as a catalyst, and DMF/KOH as a hydrogen source, in a microwave reactor. The cis-alkene 13 and the trans-alkene 15 were formed chemo- and stereoselectively under the applied conditions. The different stereochemical outcome of the

Strategies toward protecting group-free glycosylation through selective activation of the anomeric center

• A. Michael Downey and
• Michal Hocek

Beilstein J. Org. Chem. 2017, 13, 1239–1279, doi:10.3762/bjoc.13.123

• -glucose in the presence of HCl to provide the methyl glycoside (pathway a, Scheme 6). The reaction proceeds chemoselective at the anomeric position. More recent examples typically use Lewis acids [29][30][31][32][33][34] or microwave irradiation [35][36] to accelerate the reaction. However, shortcomings

Synthesis of alkynyl-substituted camphor derivatives and their use in the preparation of paclitaxel-related compounds

• M. Fernanda N. N. Carvalho,
• Rudolf Herrmann and
• Gabriele Wagner

Beilstein J. Org. Chem. 2017, 13, 1230–1238, doi:10.3762/bjoc.13.122

• applied, but CDCl3 was used as solvent. Within 10 hours, compound 21a converts cleanly into product 22a without the observation of intermediates or side products. Under microwave irradiation, the reaction is complete within 30 min at 80 °C, without impairing the selectivity. The structure of 22a is

• , RECI/QEQ-QIN/0189/2012) for financial support. The BAYER AG (Leverkusen/Germany) is acknowledged for a generous gift of 1-ethynyladamantane, and Anton Paar for the provision of a Monowave 400 microwave reactor. We are particularly grateful for the experimental assistance given by Adrian Mahamoodally

Kinetic analysis of mechanoradical formation during the mechanolysis of dextran and glycogen

• Naoki Doi,
• Yasushi Sasai,
• Yukinori Yamauchi,
• Tetsuo Adachi,
• Masayuki Kuzuya and
• Shin-ichi Kondo

Beilstein J. Org. Chem. 2017, 13, 1174–1183, doi:10.3762/bjoc.13.116

• saturation occurred and that the line shape was not distorted by excessive modulation amplitude. The square root of the microwave power versus the signal peak height was plotted, so that a microwave power level of 0.04 mW was chosen. The ESR spectral intensity was determined by double integration. The

New tricks of well-known aminoazoles in isocyanide-based multicomponent reactions and antibacterial activity of the compounds synthesized

• Maryna V. Murlykina,
• Maryna N. Kornet,
• Sergey M. Desenko,
• Svetlana V. Shishkina,
• Oleg V. Shishkin,
• Aleksander A. Brazhko,
• Vladimir I. Musatov,
• Erik V. Van der Eycken and
• Valentin A. Chebanov

Beilstein J. Org. Chem. 2017, 13, 1050–1063, doi:10.3762/bjoc.13.104

• National Academy of Sciences of Ukraine, Nauky Ave., 60, 61001, Kharkiv, Ukraine Laboratory for Organic & Microwave-Assisted Chemistry (LOMAC), KU Leuven, Celestijnenlaan 200F, B-3001, Leuven, Belgium Laboratory of Biotechnology of Physiologically Active Substances, Zaporizhzhya National University

Automating multistep flow synthesis: approach and challenges in integrating chemistry, machines and logic

• Chinmay A. Shukla and
• Amol A. Kulkarni

Beilstein J. Org. Chem. 2017, 13, 960–987, doi:10.3762/bjoc.13.97

• , electrochemical reaction, photochemical reaction, microwave, etc. On the other hand, it is also possible and in many times necessary to classify the reactions on the basis of the number of phases (gas G, liquid L, and solid S) involved in the reaction (viz. single-phase or homogeneous reaction and multiphase

Synthesis of tetrasubstituted pyrazoles containing pyridinyl substituents

• Josef Jansa,
• Ramona Schmidt,
• Ashenafi Damtew Mamuye,
• Laura Castoldi,
• Alexander Roller,
• Vittorio Pace and
• Wolfgang Holzer

Beilstein J. Org. Chem. 2017, 13, 895–902, doi:10.3762/bjoc.13.90

• accompanied by some biphenyl (Scheme 4). As well, realizing the reaction under microwave assistance (150 °C, 800 W) led to the same result. Employing the corresponding iodo derivative 3a as the starting material again resulted mainly in the formation of 2a (4 equiv Na2CO3/EtOH–H2O 4:1/Pd(dppf)Cl2 5 mol %, 24

Metal-free hydroarylation of the side chain carbon–carbon double bond of 5-(2-arylethenyl)-3-aryl-1,2,4-oxadiazoles in triflic acid

• Anna S. Zalivatskaya,
• Dmitry S. Ryabukhin,
• Marina V. Tarasenko,
• Alexander Yu. Ivanov,
• Irina A. Boyarskaya,
• Elena V. Grinenko,
• Ludmila V. Osetrova,
• Eugeniy R. Kofanov and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2017, 13, 883–894, doi:10.3762/bjoc.13.89

• ), both under thermal and microwave conditions, leads to 5-(2,2-diarylethyl)-3-aryl-1,2,4-oxadiazoles. The products are formed through the regioselective hydroarylation of the side chain carbon–carbon double bond of the starting oxadiazoles in yields up to 97%. According to NMR data and DFT calculations

• action of TfOH at elevated temperature (60 °C) or for prolonged reaction times (12 or 24 h) at room temperature. See reviews [58][59] on the dealkylation of ethers by various Brønsted and Lewis acids. Additionally, the reactions were carried out under microwave (MW) irradiation (Table 3) analogously to

• and no destruction was noticed. Conclusion We have developed an efficient method for the hydroarylation of the C=C double bond of 5-(2-arylethenyl)-3-aryl-1,2,4-oxadiazoles based on their TfOH-promoted reaction with arenes under thermal or microwave activation to form 5-(2,2-diarylethyl)-3-aryl-1,2,4