Modular synthesis of the pyrimidine core of the manzacidins by divergent Tsuji–Trost coupling

• Sebastian Bretzke,
• Stephan Scheeff,
• Felicitas Vollmeyer,
• Friederike Eberhagen,
• Frank Rominger and
• Dirk Menche

Beilstein J. Org. Chem. 2016, 12, 1111–1121, doi:10.3762/bjoc.12.107

• ) [45]. Unfortunately, this route was found to be less effective in terms of isolated yields and scalability. Thus, the iron-catalyzed procedure was applied and multigram quantities of 12 were readily obtained. As shown in Scheme 3, we next focused on the further derivatization of amine 12 towards

Cationic Pd(II)-catalyzed C–H activation/cross-coupling reactions at room temperature: synthetic and mechanistic studies

• Takashi Nishikata,
• Alexander R. Abela,
• Shenlin Huang and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2016, 12, 1040–1064, doi:10.3762/bjoc.12.99

• [211][212][213]. Many of these syntheses require large excesses of iron or other stoichiometric metals to obtain high yields (Scheme 6). As shown in Scheme 7, a synthesis that proceeds via a C–H activation strategy, however, might provide a highly efficient, alternative route originating from just

Enantioselective carbenoid insertion into C(sp³)–H bonds

• J. V. Santiago and
• A. H. L. Machado

Beilstein J. Org. Chem. 2016, 12, 882–902, doi:10.3762/bjoc.12.87

• promote the formation of a specific enantiomer. The search for the best balance of these properties of the carbenoid intermediates was also sought through the use of different metals such as copper [3], rhodium [4], iron [5], ruthenium [6], iridium [7], osmium [8], and others. From these, copper and

Syntheses of dibenzo[d,d']benzo[2,1-b:3,4-b']difuran derivatives and their application to organic field-effect transistors

• Minh Anh Truong and
• Koji Nakano

Beilstein J. Org. Chem. 2016, 12, 805–812, doi:10.3762/bjoc.12.79

• are described in Scheme 1 and Scheme 2. 3-Decylanisole was first synthesized from commercially available 3-bromoanisole via iron-catalyzed cross-coupling reaction with decylmagnesium bromide in 71% yield [47]. Lithiation of the obtained 3-decylanisole with s-BuLi and the following treatment with 2

Creating molecular macrocycles for anion recognition

• Amar H. Flood

Beilstein J. Org. Chem. 2016, 12, 611–627, doi:10.3762/bjoc.12.60

• indicated that triazoles are sterically small. In the iron complex, we saw the ferrous ion’s preference for triazole change to a water molecule when oxidized up to the harder ferric ion. This process did not occur with the terpyridine control complex. Thus, we reasoned water could easily slip past the

Antibiotics from predatory bacteria

• Juliane Korp,
• María S. Vela Gurovic and
• Markus Nett

Beilstein J. Org. Chem. 2016, 12, 594–607, doi:10.3762/bjoc.12.58

• thoroughly explored [62][67], the biological function of these cyclic depsipeptides is still not clear. In contrast, the myxochelins primarily serve as siderophores for M. xanthus DK1622, as evidenced by their iron-responsive production and complexing properties [58][59]. Recent studies also unveiled

• specific enzymatic targets for these natural products [60][68], which are not due to their iron affinity [69]. Myxalamids [70][71][72][73] and myxovirescins [74][75][76][77][78][79] are distinguished by their potent antimicrobial activities. The former are inhibitors of electron transport in the

Self and directed assembly: people and molecules

• Tony D. James

Beilstein J. Org. Chem. 2016, 12, 391–405, doi:10.3762/bjoc.12.42

• about. The project involved evaluation of the alkylation reaction of trimethylsilyl cyanide with tricarbonyl(η5-cyclohexadienyl)iron(1+) salts (Scheme 1). The reaction was shown to involve the isocyanide isomer, produced in rate-limiting pre-equilibration. The rate of reaction was proportional to the

• )iron(1+) salts. Reproduced with permission from [3]. Copyright 1987 Royal Society of Chemistry. Polymeric boronic acid receptor units developed by Wulff. Reproduced from [16]. Copyright 1982 International Union of Pure and Applied Chemistry. Acknowledgements This is a personal account describing

Highly stable and reusable immobilized formate dehydrogenases: Promising biocatalysts for in situ regeneration of NADH

• Barış Binay,
• Dilek Alagöz,
• Deniz Yildirim,
• Ayhan Çelik and
• S. Seyhan Tükel

Beilstein J. Org. Chem. 2016, 12, 271–277, doi:10.3762/bjoc.12.29

• ] reported the optimal pH values were 7.0 for both free FDH and immobilized FDH onto polydopamine-coated iron oxide nanoparticles (PD-IONPs). The optimum pH values of the both free Pseudomonas sp. 101 FDH and its immobilized form onto glyoxylagarose were reported as 7.0 [16]. The temperature–activity

Regioselective palladium-catalyzed ring-opening reactions of C1-substituted oxabicyclo[2,2,1]hepta-2,5-diene-2,3-dicarboxylates

• Michael Edmunds,
• Mohammed Abdul Raheem,
• Rebecca Boutin,
• Katrina Tait and
• William Tam

Beilstein J. Org. Chem. 2016, 12, 239–244, doi:10.3762/bjoc.12.25

• % respectively (Table 1, entries 9 and 4). The Lewis acid additives gave a large range of yields (Table 1, entries 10–14). Iron and aluminium chlorides gave low yields (22%, Table 1, entry 10 and 29%, entry 11), zirconium chloride and zinc iodide gave moderate yields (47%, Table 1, entry 12 and 48%, entry 13

My maize and blue brick road to physical organic chemistry in materials

• Anne J. McNeil

Beilstein J. Org. Chem. 2016, 12, 229–238, doi:10.3762/bjoc.12.24

• within each field. Learning that light emitted from stars comes from hydrogen fusing to form helium, or that a pond’s carbonate concentration affects buffering capacity and health, or that traces of iron in quartz lead to the purple color of amethyst, was all fascinating to me. It is cliché, but I

Base metal-catalyzed benzylic oxidation of (aryl)(heteroaryl)methanes with molecular oxygen

• Hans Sterckx,
• Johan De Houwer,
• Carl Mensch,
• Wouter Herrebout,
• Kourosch Abbaspour Tehrani and
• Bert U. W. Maes

Beilstein J. Org. Chem. 2016, 12, 144–153, doi:10.3762/bjoc.12.16

• , benzyldiazines and benzyl(iso)quinolines was successfully oxidized to the corresponding benzylic ketones using a copper or iron catalyst and molecular oxygen as the stoichiometric oxidant. Application of the protocol in API synthesis is exemplified by the alternative synthesis of a precursor to the antimalarial

• Liu and Bi [24]. This useful transformation makes use of CuI/O2 in DMSO to convert methyl ketones into aldehydes in a sustainable manner. Recently our group reported a synthetic protocol for the copper- and iron-catalyzed aerobic oxidation of the methylene group of aryl(di)azinylmethanes using acetic

• the limit of 250 ppm. Iron contents were slightly higher ranging from 29 to 57 ppm but again still well below the regulatory maximum value (see Supporting Information File 1, Figure S1). It should be noted that these values pertain to the purified compounds after column chromatography. The influence

Supramolecular polymer assembly in aqueous solution arising from cyclodextrin host–guest complexation

• Jie Wang,
• Zhiqiang Qiu,
• Yiming Wang,
• Li Li,
• Xuhong Guo,
• Duc-Truc Pham,
• Stephen F. Lincoln and
• Robert K. Prud’homme

Beilstein J. Org. Chem. 2016, 12, 50–72, doi:10.3762/bjoc.12.7

• with (a). 5.4 Redox-responsive materials Redox-responsive hydrogel systems have potential applications as environmentally benign electro-functional materials. Such systems require a redox couple as a central component. One such system is that in which the oxidation states of iron are 0 and I in

• -CD·FCA has a much lower K ≤ 20 M−1. Thus, the oxidation state of iron determines the relative stabilities of β-CD·FCA− and β-CD·FCA. Conjointly, these complexes may potentially be used as an electrochemical switch in a supramolecular system. In 2006, Harada et al. realized this potential in a redox

• ferrocene iron(0) is oxidized to ferrocene iron(I). With iron in oxidation state I, the ferrocene substituents assume uni-positive charges and consequently aggregate weakly with a corresponding decrease in solution viscosity. 5.5 Self-healing systems Because of their ability to form host–guest complexes in

Copper-catalyzed intermolecular oxyamination of olefins using carboxylic acids and O-benzoylhydroxylamines

• Brett N. Hemric and
• Qiu Wang

Beilstein J. Org. Chem. 2016, 12, 22–28, doi:10.3762/bjoc.12.4

• Liu reported a palladium-catalyzed introduction of phthalimide (HNPhth) and acetate functionalities to terminal allylic and homoallylic ethers in the presence of an iodine oxidant (Scheme 1B) [13]. The Yoon lab also developed copper- and iron-catalyzed olefin difunctionalization reactions with

• oxaziridine derivatives to create 1,3-oxazolidines, which were readily converted to the 1,2-oxyamino functionality (Scheme 1C) [14][15]. Recently, the Xu lab developed another iron-catalyzed intermolecular olefin-oxyamination reaction with O-alkylhydroxylamides to construct either 1,2-oxyamino or 2

Effective immobilisation of a metathesis catalyst bearing an ammonium-tagged NHC ligand on various solid supports

• Krzysztof Skowerski,
• Jacek Białecki,
• Stefan J. Czarnocki,
• Karolina Żukowska and
• Karol Grela

Beilstein J. Org. Chem. 2016, 12, 5–15, doi:10.3762/bjoc.12.2

• , University of Warsaw, Żwirki i Wigury 101, 02-089 Warsaw, Poland 10.3762/bjoc.12.2 Abstract An ammonium-tagged ruthenium complex, 8, was deposited on several widely available commercial solid materials such as silica gel, alumina, cotton, filter paper, iron powder or palladium on carbon. The resulting

• is important to note that in this study we focused on establishing the scope of this heterogenisation method, i.e., by testing a wide number of potential supports, such as silica, alumina, charcoal, iron powder, as well as biocompatible wool and paper, and by examining different catalyst removal

• endeavour aimed at getting a broader perspective. Immobilisation of 8 on iron powder First, we attempted to prepare a model for a magnetically separable catalyst [55]. This idea has been explored previously by attaching tagged Ru complexes to specially designed magnetically active nanoparticles. We wondered

Recent advances in metathesis-derived polymers containing transition metals in the side chain

• Ileana Dragutan,
• Valerian Dragutan,
• Bogdan C. Simionescu,
• Albert Demonceau and
• Helmut Fischer

Beilstein J. Org. Chem. 2015, 11, 2747–2762, doi:10.3762/bjoc.11.296

• electrochemistry, sensing, catalysis, nanomaterials, etc. [37][38][39][40]. Not surprisingly, therefore, attention of researchers has turned first on metallopolymers containing ferrocene [33][34][41][42][43]. Review Iron-containing polymers Following the first successful application of Mo–alkylidene catalysts by

• Schrock and coworkers [42] in ROMP to ferrocene-appended monomers as well as the rapid expansion of Grubbs Ru metathesis catalysts [28][29][30], a vast number of iron-containing polymers have been synthesized by ROMP up to now [33][34][42][43]. In a compelling work, Astruc et al. [44] reported a

Iron complexes of tetramine ligands catalyse allylic hydroxyamination via a nitroso–ene mechanism

• David Porter,
• Belinda M.-L. Poon and
• Peter J. Rutledge

Beilstein J. Org. Chem. 2015, 11, 2549–2556, doi:10.3762/bjoc.11.275

• David Porter Belinda M.-L. Poon Peter J. Rutledge School of Chemistry F11, The University of Sydney, NSW 2006, Australia 10.3762/bjoc.11.275 Abstract Iron(II) complexes of the tetradentate amines tris(2-pyridylmethyl)amine (TPA) and N,N′-bis(2-pyridylmethyl)-N,N′-dimethylethane-1,2-diamine (BPMEN

• -nitroso intermediate. Asymmetric induction is not observed using the chiral tetramine ligand (+)-(2R,2′R)-1,1′-bis(2-pyridylmethyl)-2,2′-bipyrrolidine ((R,R′)-PDP). Keywords: CH activation; hydroxyamination; iron catalysis; nitroso-ene; Introduction The selective functionalization of C–H bonds is an

• ], manganese- [19][20][21], iron- [23][24], copper- [22][31], rhenium- [26], and rhodium- [27] based reagents. The recent resurgence of interest in the nitroso–ene reaction builds on earlier work by Sharpless, Nicolas, Jørgensen and others. Sharpless reported allylic amination of 2-methyl-2-hexene with N-(p

2-Hetaryl-1,3-tropolones based on five-membered nitrogen heterocycles: synthesis, structure and properties

• Yury A. Sayapin,
• Inna O. Tupaeva,
• Alexandra A. Kolodina,
• Eugeny A. Gusakov,
• Vitaly N. Komissarov,
• Igor V. Dorogan,
• Nadezhda I. Makarova,
• Anatoly V. Metelitsa,
• Valery V. Tkachev,
• Sergey M. Aldoshin and
• Vladimir I. Minkin

Beilstein J. Org. Chem. 2015, 11, 2179–2188, doi:10.3762/bjoc.11.236

• NMR spectroscopy has been corrected and attributed to a derivative of 1,3-tropolone system 2 [17]. Later on this conclusion has been corroborated by the preparation of a series of 2-benzoyl-3-hydroxy-5,6,7-trichlorotropones 3 by the iron trichloride-catalyzed reaction of o-chloranil with acetophenones

A new approach to ferrocene derived alkenes via copper-catalyzed olefination

• Vasily M. Muzalevskiy,
• Aleksei V. Shastin,
• Alexandra D. Demidovich,
• Namiq G. Shikhaliev,
• Abel M. Magerramov,
• Victor N. Khrustalev,
• Rustem D. Rakhimov,
• Sergey Z. Vatsadze and
• Valentine G. Nenajdenko

Beilstein J. Org. Chem. 2015, 11, 2072–2078, doi:10.3762/bjoc.11.223

• was found only in the case of bis(halovinyl)ferrocenes. Our results clearly indicate that the anodic and cathodic electrochemical processes proceed on different parts of the molecules. While in the anodic region the changes are localized on the iron atom, the electron transfer from the cathode occurs

• current values of oxidation at the iron atom. These findings allow us to state that the synthesized molecules are promising starting materials for the electrochemical synthesis of ferrocene-containing conjugated polymers. Conclusion In conclusion, a novel stereoselective route to ferrocenyl haloalkenes

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• the pyridine derivative 220 with an excess amount of the 5-hexenylmagnesium bromide in the presence of a catalytic amount of iron complex 18 as the precatalyst provides the dialkylation product 221 (75%). The treatment of the hydrochloride solution of 221 with Ru catalyst 17 in a dilute CH2Cl2

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

• cutting apart a laboratory stirring bar and removing the iron magnet. After cutting stirring bars open, we found that some of the iron bars were corroded (Figure 17). While we cannot exclude a possibility that the manufacturer used corroded bars, a more likely explanation is that they underwent corrosion

• hypothesis, we carried out a reaction of bromine with benzene. In the absence of a catalyst there is only a very slow reaction. However, in the presence of a Lewis acid catalyst there is a fast bromination reaction. Since iron reacts with bromine to produce iron(III) bromide, a stirring bar may conceivably

• after 8 days. For a comparison, a reaction was carried out with a cut stirring bar, so that its iron core was exposed, resulted in a very fast reaction and the formation of bromobenzene in a high yield (Figure 20b). Magnetic stirring bars have been in use for a rather long time and, had they had any

Adsorption mechanism and valency of catechol-functionalized hyperbranched polyglycerols

• Stefanie Krysiak,
• Qiang Wei,
• Klaus Rischka,
• Andreas Hartwig,
• Rainer Haag and
• Thorsten Hugel

Beilstein J. Org. Chem. 2015, 11, 828–836, doi:10.3762/bjoc.11.92

• reduced state [5][9]. The byssal plaque also shows strong cohesion through crosslinks. The cysteins can crosslink with DOPA and the oxidized DOPA (semiquinones) can crosslink via radical addition. Furthermore, crosslinking by iron chelate complexes of DOPA improves cohesion [10]. The adhesion of a single

Synthesis of tripodal catecholates and their immobilization on zinc oxide nanoparticles

• Franziska Klitsche,
• Julian Ramcke,
• Julia Migenda,
• Andreas Hensel,
• Tobias Vossmeyer,
• Horst Weller,
• Silvia Gross and
• Wolfgang Maison

Beilstein J. Org. Chem. 2015, 11, 678–686, doi:10.3762/bjoc.11.77

• ], carboxylates [5] and phosphates [6] as well as phosphonates [7] for metal and metal oxide surfaces. In addition, bifunctional catechols like dopamine or DOPA (L-3,4-dihydroxyphenylalanine, Figure 1B), have received considerable interest as anchor groups for important metal surfaces such as titanium oxide, iron

Electrochemical oxidation of cholesterol

• Jacek W. Morzycki and
• Andrzej Sobkowiak

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

• of an iron cluster, was described in the 1980s by Barton et al. [23]. The system (Gif system) showed an unusual regioselectivity – the secondary positions were preferentially oxidized. An identical selectivity was also observed in an electrochemical version of the reaction (Gif–Orsay system), in

• ]. In Gif systems pyridine is not only used as a solvent but it also acts as a ligand on the iron complex [28]. Different Fe(II) or Fe(III) picolinate (PA) and dipicolinate (DPA) complexes as catalysts of oxygenation reactions have been studied by the Sawyer [29][30][31], Barton [31][32], and Kotani

• %), along with the 7-oxo product 9a (15–19%). In addition to these products, epoxide 10a (1.5–3%) was also formed under constant current conditions (Scheme 3). Irrespective of the iron complex used, the reactions afforded the 7α-hydroxylated product 7a in a large excess. The authors postulated the formation

Cross-dehydrogenative coupling for the intermolecular C–O bond formation

• Igor B. Krylov,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2015, 11, 92–146, doi:10.3762/bjoc.11.13

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

• (Scheme 1) [9], Bischler–Napieralski reactions [10], reduction of phenanthridones [11][12], free radical methodology, palladium/rhodium/iron-catalysed reactions, etc. One of the approaches to the large variety of 6-arylphenanthridine derivatives was the synthesis starting from benzotriazole derivatives of

• rather expensive; therefore efforts were made to replace them with cheaper analogues. One successful approach included iron(III) acetylacetonate in acetic acid as catalytic agent (Scheme 16) [37], whereby O-acetyl oximes obtained from 2′-arylacetophenones underwent N–O bond cleavage and intramolecular N

• 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