Copolymerization of epoxides with cyclic anhydrides catalyzed by dinuclear cobalt complexes

• Yo Hiranoi and
• Koji Nakano

Beilstein J. Org. Chem. 2018, 14, 2779–2788, doi:10.3762/bjoc.14.255

• synthetic method for polyesters as the polymers’ architectures and properties can be easily controlled depending on the combination of two monomers. Thus, a variety of catalyst designs has been reported to prepare the desired copolymers efficiently. We herein report dinuclear cobalt–salen complexes with a

Microfluidic light-driven synthesis of tetracyclic molecular architectures

• Javier Mateos,
• Nicholas Meneghini,
• Marcella Bonchio,
• Nadia Marino,
• Tommaso Carofiglio,
• Xavier Companyó and
• Luca Dell’Amico

Beilstein J. Org. Chem. 2018, 14, 2418–2424, doi:10.3762/bjoc.14.219

• synthetic method for the direct assembly of highly functionalized tetracyclic pharmacophoric cores. Coumarins and chromones undergo diastereoselective [4 + 2] cycloaddition reactions with light-generated photoenol intermediates. The reactions occur by aid of a microfluidic photoreactor (MFP) in high yield

• of harsh reaction conditions (e.g., 250 °C), leading to a mixture of regio- and diastereoisomers in moderate yields [10]. Hence, the development of an efficient synthetic method to access these privileged motifs still represents an open task in synthetic chemistry. The method presented herein is

Catalyst-free synthesis of 4-acyl-NH-1,2,3-triazoles by water-mediated cycloaddition reactions of enaminones and tosyl azide

• Lu Yang,
• Yuwei Wu,
• Yiming Yang,
• Chengping Wen and
• Jie-Ping Wan

Beilstein J. Org. Chem. 2018, 14, 2348–2353, doi:10.3762/bjoc.14.210

• , Figure 1). Moreover, it is notable that no N-sulfonyl-1,2,3-triazole was isolated from any of the above experiments, indicating the excellent chemoselectivity of the present synthetic method. In order to illustrate the potential application of this authentically green synthetic method, a gram scale

Glycosylation reactions mediated by hypervalent iodine: application to the synthesis of nucleosides and carbohydrates

• Yuichi Yoshimura,
• Hideaki Wakamatsu,
• Yoshihiro Natori,
• Yukako Saito and
• Noriaki Minakawa

Beilstein J. Org. Chem. 2018, 14, 1595–1618, doi:10.3762/bjoc.14.137

• viewpoint of the synthetic method, the reaction would be useful for dehomologation of aldoses and preparation of chiral synthons deriving from sugars. The reaction procedure involves the initial formation of an alkoxy anomeric radical by a hypervalent iodine reagent in the presence of iodine, which triggers

Synthesis of trifluoromethylated 2H-azirines through Togni reagent-mediated trifluoromethylation followed by PhIO-mediated azirination

• Jiyun Sun,
• Xiaohua Zhen,
• Huaibin Ge,
• Guangtao Zhang,
• Xuechan An and
• Yunfei Du

Beilstein J. Org. Chem. 2018, 14, 1452–1458, doi:10.3762/bjoc.14.123

• -dimethyl-1,2-benziodoxole (1’, Figure 2), are effective and efficient hypervalent iodine reagents for trifluoromethylation reactions of a variety of substrates [22][23]. These reagents have found wide applications in the area of organofluorine chemistry, synthetic method development as well as medicinal

An efficient and facile access to highly functionalized pyrrole derivatives

• Meng Gao,
• Wenting Zhao,
• Hongyi Zhao,
• Ziyun Lin,
• Dongfeng Zhang and
• Haihong Huang

Beilstein J. Org. Chem. 2018, 14, 884–890, doi:10.3762/bjoc.14.75

• methods have been reported till now to synthesize pyrroles and pyrrole containing analogs [6]. In the past decade, 1,3-dipolar cycloaddition has become a fundamental synthetic method for the construction of nitrogen-containing five-membered heterocycles including pyrroles. It is worth to note that

Methyl isocyanide as a convertible functional group for the synthesis of spirocyclic oxindole γ-lactams via post-Ugi-4CR/transamidation/cyclization in a one-pot, three-step sequence

• Amarendar Reddy Maddirala and
• Peter R. Andreana

Beilstein J. Org. Chem. 2018, 14, 875–883, doi:10.3762/bjoc.14.74

• synthetic method for these molecules that allows for structural diversity is also important but not necessarily trivial. For these and other reasons, we became interested in synthesizing spiro[indoline-3,2'-pyrrole]-2,5'(1'H)-dione and spiro[indoline-3,2'-pyrrolidine]-2,5'-dione scaffolds (a class of

Copper-catalyzed asymmetric methylation of fluoroalkylated pyruvates with dimethylzinc

• Kohsuke Aikawa,
• Kohei Yabuuchi,
• Kota Torii and
• Koichi Mikami

Beilstein J. Org. Chem. 2018, 14, 576–582, doi:10.3762/bjoc.14.44

• electrophile in the presence of a chiral Lewis acid complex [20][21][22][23][24][25][26][27]. However, the synthetic method for chiral α-trifluoromethylated tertiary alcohols via methylation of trifluoropyruvate is quite limited, although several drug candidates bearing this chiral trifluoromethylated moiety

Stimuli-responsive oligonucleotides in prodrug-based approaches for gene silencing

• Françoise Debart,
• Christelle Dupouy and
• Jean-Jacques Vasseur

Beilstein J. Org. Chem. 2018, 14, 436–469, doi:10.3762/bjoc.14.32

• ). These results suggest that 2’-O-MDTM siRNAs fulfill some features of typical prodrug-type siRNAs. Similarly, our group has developed a post-synthetic method on a solid support to introduce various disulfide bond-containing groups at the 2’-OH of RNAs [15]. Using this versatile method, one precursor, 2

• cells in the absence of any carriers remained to be demonstrated. The robust synthetic method developed in 2014 [49] made 2’-PivOM-modified siRNAs readily available. To improve their lipophilic features, one methyl of the tert-butyl moiety in the PivOM groups was replaced by one phenyl, resulting in the

• deprotected under photolysis restoring the activity of the native siRNA. As stated previously, the introduction of a photoreactive moiety into the phosphodiester backbone of an ON with diazo compounds is not specific. Xiang et al. developed a more efficient and specific post-synthetic method. It is based on

Diels–Alder cycloadditions of N-arylpyrroles via aryne intermediates using diaryliodonium salts

• Huangguan Chen,
• Jianwei Han and
• Limin Wang

Beilstein J. Org. Chem. 2018, 14, 354–363, doi:10.3762/bjoc.14.23

• be easily obtained in 63% yield with palladium on carbon catalyst under hydrogen atmosphere at room temperature (Scheme 3). Conclusion In summary, we have demonstrated a Diels–Alder cycloaddition of N-arylpyrroles by using diaryliodonium salts under mild conditions. The synthetic method was extended

Solvent-free copper-catalyzed click chemistry for the synthesis of N-heterocyclic hybrids based on quinoline and 1,2,3-triazole

• Martina Tireli,
• Silvija Maračić,
• Stipe Lukin,
• Marina Juribašić Kulcsár,
• Dijana Žilić,
• Mario Cetina,
• Ivan Halasz,
• Silvana Raić-Malić and
• Krunoslav Užarević

Beilstein J. Org. Chem. 2017, 13, 2352–2363, doi:10.3762/bjoc.13.232

• establish the benefits of each synthetic method. The structures of all products were determined by single-crystal X-ray diffraction, and the products were additionally characterized by NMR, Raman and FTIR–ATR spectroscopic methods. Results and Discussion Conventional solution-based click reactions for the

Homologated amino acids with three vicinal fluorines positioned along the backbone: development of a stereoselective synthesis

• Raju Cheerlavancha,
• Ahmed Ahmed,
• Yun Cheuk Leung,
• Aggie Lawer,
• Qing-Quan Liu,
• Marina Cagnes,
• Hee-Chan Jang,
• Xiang-Guo Hu and
• Luke Hunter

Beilstein J. Org. Chem. 2017, 13, 2316–2325, doi:10.3762/bjoc.13.228

• piperidine-2,5-dione scaffold might prove more tractable in the future, but this has not yet been investigated in our laboratories. Since the first two approaches to target 6 (Scheme 1 and Scheme 2) were unsuccessful, we reasoned that a better-precedented synthetic method was needed. O’Hagan and co-workers

Mechanochemical synthesis of thioureas, ureas and guanidines

• Vjekoslav Štrukil

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

• , 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

• structure in a one-pot two-step mechanochemical sequence. Another typical synthetic method for the preparation of thioureas, particularly if the desired isothiocyanate is not available, is the condensation of an amine with carbon disulfide [36]. This reaction proceeds through the formation of a

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

• relatively easy to prepare and can be obtained in different size and morphology by essentially controlling the synthetic method and experimental conditions. As a result of the excellent catalytic activity of NPs, they can be used under mild and, in some cases, in environmental sustainable conditions. In

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

• successfully developed a new synthetic method for 2,4,5-trisubstituted oxazoles comprising of carboxylic acids, amino acids, and boronic acids in a one-pot oxazole synthesis with following Ni-catalyzed Suzuki–Miyaura coupling. The combination of various starting materials, which are commercially available

An eco-compatible strategy for the diversity-oriented synthesis of macrocycles exploiting carbohydrate-derived building blocks

• Sushil K. Maurya and
• Rohit Rana

Beilstein J. Org. Chem. 2017, 13, 1106–1118, doi:10.3762/bjoc.13.110

• produce moderate yields. Thus, we have successfully demonstrated novel application of build-couple-pair (B/C/P) strategy in DOS and synthesized 13 new macrocycles (4a–m). This synthetic method represents a significant advantage over current routes for sugar embedded macrocycles where reactions are rapid

Nucleophilic and electrophilic cyclization of N-alkyne-substituted pyrrole derivatives: Synthesis of pyrrolopyrazinone, pyrrolotriazinone, and pyrrolooxazinone moieties

• Işıl Yenice,
• Sinan Basceken and
• Metin Balci

Beilstein J. Org. Chem. 2017, 13, 825–834, doi:10.3762/bjoc.13.83

• synthetic method for the construction of the pyrrolopyrazinone core structure as well as for its derivatives is not described in the literature [14]. Recently, we developed new synthetic methodologies for the synthesis of various pyrrole-fused new heterocycles using alkyne cyclization reactions [15][16][17

Fluorescent carbon dots from mono- and polysaccharides: synthesis, properties and applications

• Stephen Hill and
• M. Carmen Galan

Beilstein J. Org. Chem. 2017, 13, 675–693, doi:10.3762/bjoc.13.67

• crystallinity with blue-green emission. Most reported CD syntheses, regardless of the type of starting material or synthetic method, tend to produce CDs with blue-green fluorescence emission. Jana et al. reported a carbohydrate-based preparation to access yellow and red emissive CDs, demonstrating that fine

Fast and efficient synthesis of microporous polymer nanomembranes via light-induced click reaction

• Qi An,
• Youssef Hassan,
• Xiaotong Yan,
• Peter Krolla-Sidenstein,
• Tawheed Mohammed,
• Mathias Lang,
• Stefan Bräse and
• Manuel Tsotsalas

Beilstein J. Org. Chem. 2017, 13, 558–563, doi:10.3762/bjoc.13.54

• investigations. The thin films show high mechanical stability as evidenced by the possibility to create feestanding membranes across holes of about 3–5 µm diameter. The rapid and scalable synthetic method for CMP nanomembranes described in this article, along with the possibility to transfer the nanomembranes to

First DMAP-mediated direct conversion of Morita–Baylis–Hillman alcohols into γ-ketoallylphosphonates: Synthesis of γ-aminoallylphosphonates

• Marwa Ayadi,
• Haitham Elleuch,
• Emmanuel Vrancken and
• Farhat Rezgui

Beilstein J. Org. Chem. 2016, 12, 2906–2915, doi:10.3762/bjoc.12.290

• next investigated the scope and the limitations of this synthetic method. We have thus examined, the behavior of the acyclic MBH alcohol 3a [46][47] towards triethyl phosphite under the above conditions (1 equiv of DMAP, solvent-free conditions, 80 °C, Scheme 4). We were pleased to note that the

Versatile synthesis of end-reactive polyrotaxanes applicable to fabrication of supramolecular biomaterials

• Atsushi Tamura,
• Asato Tonegawa,
• Yoshinori Arisaka and
• Nobuhiko Yui

Beilstein J. Org. Chem. 2016, 12, 2883–2892, doi:10.3762/bjoc.12.287

• polyrotaxanes (PRXs) with reactive functional groups at the terminals of the axle polymers are attractive candidates for the design of supramolecular materials. Herein, we describe a novel and simple synthetic method for end-reactive PRXs using bis(2-amino-3-phenylpropyl) poly(ethylene glycol) (PEG-Ph-NH2) as

Selective and eco-friendly procedures for the synthesis of benzimidazole derivatives. The role of the Er(OTf)₃ catalyst in the reaction selectivity

• Natividad Herrera Cano,
• Jorge G. Uranga,
• Mónica Nardi,
• Antonio Procopio,
• Daniel A. Wunderlin and
• Ana N. Santiago

Beilstein J. Org. Chem. 2016, 12, 2410–2419, doi:10.3762/bjoc.12.235

• environmentally friendly synthetic method, to obtain different derivatives containing the benzimidazole core by a one-pot reaction. Additionally, Er(OTf)3 was selected as the catalyst to achieve the selective formation of products in order to avoid tedious work-up and product separation procedures. Moreover

Efficient mechanochemical synthesis of regioselective persubstituted cyclodextrins

• Laszlo Jicsinszky,
• Marina Caporaso,
• Katia Martina,
• Emanuela Calcio Gaudino and
• Giancarlo Cravotto

Beilstein J. Org. Chem. 2016, 12, 2364–2371, doi:10.3762/bjoc.12.230

• very strong complexes with not only the native but with the substituted CDs, too. Although a solvent-free synthetic method does not solve the problem of complexation but the reduced amount of reagents can simplify the purification. Heptakis(6-azido-6-deoxy)-β-CD is the precursor to per-6-amino-β-CD

• sometimes affected the reaction rate, a solvent-free synthetic method may simplify the purification of compounds 5 and 6. Conclusion Syntheses of per-6-substituted CD derivatives can be effectively carried out in a ball mill under solvent-free conditions. In many cases, ball mill preparations display a

The direct oxidative diene cyclization and related reactions in natural product synthesis

• Juliane Adrian,
• Leona J. Gross and
• Christian B. W. Stark

Beilstein J. Org. Chem. 2016, 12, 2104–2123, doi:10.3762/bjoc.12.200

• Juliane Adrian Leona J. Gross Christian B. W. Stark Fachbereich Chemie, Institut für Organische Chemie, Universität Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany 10.3762/bjoc.12.200 Abstract The direct oxidative cyclization of 1,5-dienes is a valuable synthetic method for the (dia

• -acetylperrhenate, a synthetic method first reported in 1995 [110][111]. Bis-homoallylic dienols 65 and 66 were synthesized from trans-ethyl heptadec-4-enoate (63) via diene 64. A Re(VII)-mediated type C oxidative cyclization furnished the bis-THF products 67 and 68 in 49% and 29% yield, respectively. Both THF

Microwave-assisted cyclizations promoted by polyphosphoric acid esters: a general method for 1-aryl-2-iminoazacycloalkanes

• Jimena E. Díaz,
• María C. Mollo and
• Liliana R. Orelli

Beilstein J. Org. Chem. 2016, 12, 2026–2031, doi:10.3762/bjoc.12.190

• case, PPA esters activate the amidic oxygen and, at the same time, react chemically with water. We hypothesized that applying similar reaction conditions to ω-arylaminonitriles could lead to 1-aryl-2-imino-1-azacycloalkanes (Scheme 1, reaction 2), providing a novel synthetic method for these