Photocatalytic formation of carbon–sulfur bonds

• Alexander Wimmer and
• Burkhard König

Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4

• . Photoredox-active metal complexes or organic dyes are used to initiate photo-induced single-electron transfer (SET) processes upon excitation with visible-light. Such photooxidations or photoreductions yield reactive organic radicals, which can undergo unique bond forming reactions, under very mild

Comparative profiling of well-defined copper reagents and precursors for the trifluoromethylation of aryl iodides

• Peter T. Kaplan,
• Jessica A. Lloyd,
• Mason T. Chin and
• David A. Vicic

Beilstein J. Org. Chem. 2017, 13, 2297–2303, doi:10.3762/bjoc.13.225

• induction period, whereas the induction period for A2 was short. Conclusion In summary, we have determined that in DMF the best trifluoromethylating agent was generated in situ using the [Cu(O-t-Bu)]4/Me3SiCF3/phen combination. However, when optimized solvents were employed, other metal complexes and

Curcuminoid–BF₂ complexes: Synthesis, fluorescence and optimization of BF₂ group cleavage

• Henning Weiss,
• Jeannine Reichel,
• Helmar Görls,
• Kilian Rolf Anton Schneider,
• Mathias Micheel,
• Michael Pröhl,
• Michael Gottschaldt,
• Benjamin Dietzek and
• Wolfgang Weigand

Beilstein J. Org. Chem. 2017, 13, 2264–2272, doi:10.3762/bjoc.13.223

• ongoing research to increase the selectivity of antitumor active metal complexes [17][18][19][20][21][22], our focus was on the synthesis of curcuminoids that could serve as building blocks to attach sugars like D-fructose or D-glucose [23]. Due to the easy accessibility to azido sugars [24][25] we

Main group mechanochemistry

• Agota A. Gečiauskaitė and
• Felipe García

Beilstein J. Org. Chem. 2017, 13, 2068–2077, doi:10.3762/bjoc.13.204

• completion. A rare example of a one-pot multistep ball milling reaction is the case of an electron-rich aniline derivative that produced 4 in good yield without the need for ligand isolation. Previously reported examples typically employ “preformed” ligands and metal complexes [68][86], raising the

• orthogonality of multistep mechanochemical synthesis and widening its applicability. A significant example of the transformative potential of mechanochemistry is its ability to produce metal complexes directly from bulk metal or metal oxides [66]. Within this context, the LAG synthesis of germanes (GeR4

Pd(OAc)₂/Ph₃P-catalyzed dimerization of isoprene and synthesis of monoterpenic heterocycles

• Dominik Kellner,
• Maximilian Weger,
• Andrea Gini and
• Olga García Mancheño

Beilstein J. Org. Chem. 2017, 13, 1807–1815, doi:10.3762/bjoc.13.175

• formed: tail-to-tail, head-to-tail, tail-to-head and head-to-head (Figure 1). In addition to the linear dimeric products, cyclic monoterpenes such as limonene can also be formed as byproducts. A number of transition metal complexes can be used as catalysts in the dimerization of isoprene. In one hand

Chiral phase-transfer catalysis in the asymmetric α-heterofunctionalization of prochiral nucleophiles

• Johannes Schörgenhumer,
• Maximilian Tiffner and
• Mario Waser

Beilstein J. Org. Chem. 2017, 13, 1753–1769, doi:10.3762/bjoc.13.170

• use of chiral metal complexes, or chiral organocatalysts have been reported, and the use of chiral PTCs became a powerful strategy herein too [44][56][57][73][74][75][76][77][78][79]. The seminal report on asymmetric phase-transfer-catalysed electrophilic α-fluorinations of prochiral carbonyl

Chemical systems, chemical contiguity and the emergence of life

• Terrence P. Kee and
• Pierre-Alain Monnard

Beilstein J. Org. Chem. 2017, 13, 1551–1563, doi:10.3762/bjoc.13.155

• processes pertaining to its synthesis/formation: information polymer, functional catalysts or self-assembly/stability of the compartment. (B) A higher degree of complexity can be attained by using chemicals that by themselves already link to two component functions: for instance, metal complexes that can

Mechanochemical borylation of aryldiazonium salts; merging light and ball milling

• José G. Hernández

Beilstein J. Org. Chem. 2017, 13, 1463–1469, doi:10.3762/bjoc.13.144

• the photodimerizations of olefins by manual grinding of the reactants followed by long UV-light exposure [10], or by vortex grinding [11]. However, until now, studies of photocatalyzed mechanochemical reactions involving, for example, metal complexes [12] or organic photocatalysts (PC) [13] has been

Synthesis of oligonucleotides on a soluble support

• Harri Lönnberg

Beilstein J. Org. Chem. 2017, 13, 1368–1387, doi:10.3762/bjoc.13.134

• needed. Spectroscopic studies on structure, dynamics and recognition of ONs by other biopolymers, small molecules or metal complexes, for example, may consume ONs in amounts that cannot be conveniently reached by lab-scale solid-phase synthesizers. In addition to synthesis on a soluble support

Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

• Carmen Moreno-Marrodan,
• Francesca Liguori and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73

• ], in the presence of 2.5–30% amine additives. A variety of other single alkyne substrates have been hydrogenated under continuous-flow conditions using packed catalysts consisting of immobilized metal complexes. We refer the readers to the specific literature for these systems [178][179]. Substrate

Synthesis of 1-indanones with a broad range of biological activity

• Marika Turek,
• Dorota Szczęsna,
• Marek Koprowski and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

• diesters: In 1951, Gilmore has demonstrated that use of esters, rather than free arylpropionic acids in phosphoric acid, in the presence of phosphorus pentoxide also led to 1-indanones in equally good or even better yields [32]. Transition metal complexes have been used by Negishi et al. as catalysts in

• using lithium, nickel and palladium catalysts (Scheme 15). A general mechanism illustrating the role of transition metal complexes and CO in this reaction is shown in Scheme 15. Cyclic esters were also used in the syntheses of 1-indanones. Thus, by adding β-propiolactone to aluminum chloride in benzene

The reductive decyanation reaction: an overview and recent developments

• Jean-Marc R. Mattalia

Beilstein J. Org. Chem. 2017, 13, 267–284, doi:10.3762/bjoc.13.30

• removal of a beneficial functional group. The electron-withdrawing properties of the nitrile functional group appear beneficial in a variety of reactions [1][2]. This group coordinates metal complexes and can be used as a directing group for C–H bond activation reactions catalyzed by transition metals [3

The synthesis of α-aryl-α-aminophosphonates and α-aryl-α-aminophosphine oxides by the microwave-assisted Pudovik reaction

• Erika Bálint,
• Ádám Tajti,
• Anna Ádám,
• István Csontos,
• Konstantin Karaghiosoff,
• Mátyás Czugler,
• Péter Ábrányi-Balogh and
• György Keglevich

Beilstein J. Org. Chem. 2017, 13, 76–86, doi:10.3762/bjoc.13.10

• use of many types of catalysts, such as acids (HCOOH) [15] or bases (NaOH [16], 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) [17], tetramethylguanidine (TMG) [18][19]), p-toluenesulfonyl chloride [20], metal salts (MgSO4) [21], CdI2 [22]), metal complexes (BF3·EtO2 [23][24], t-PcAlCl [15]), and phase

Extrusion – back to the future: Using an established technique to reform automated chemical synthesis

• Deborah E. Crawford

Beilstein J. Org. Chem. 2017, 13, 65–75, doi:10.3762/bjoc.13.9

• interactions upon mixing, but these did not involve the formation of a covalent bond. However, James et al. report on the formation of covalent bonds in metal-organic frameworks (MOFs) and discrete metal complexes by TSE, under solvent-free conditions or in the presence of stoichiometric amounts of MeOH [2

• prepared in batch. PXRD analysis also indicated that highly crystalline materials were produced from the extrusion process, prior to any post process purification [2]. Two discrete metal complexes have been synthesised by extrusion, involving the reaction between salenH2 and nickel acetate dihydrate as

Protonated paramagnetic redox forms of di-o-quinone bridged with p-phenylene-extended TTF: A EPR spectroscopy study

• Nikolay O. Chalkov,
• Vladimir K. Cherkasov,
• Gleb A. Abakumov,
• Andrey G. Starikov and
• Viacheslav A. Kuropatov

Beilstein J. Org. Chem. 2016, 12, 2450–2456, doi:10.3762/bjoc.12.238

• in trianion radical metal complexes. The character of the spin-density distribution in this species is similar as it was observed for its monoprotonated analogue (1·)H. The EPR spectrum is centered at giso = 2.0060 and it was also interpreted as a triplet of triplets (both 1:2:1) of doublets (Figure

Organometallic chemistry

• Bernd F. Straub,
• Rolf Gleiter,
• Claudia Meier and
• Lutz H. Gade

Beilstein J. Org. Chem. 2016, 12, 2216–2221, doi:10.3762/bjoc.12.213

• studied the electronic structure of organo-transition metal complexes by extended Hückel model calculations [14][17][20][28][39][49][50][54][57]. In 1978, he completed his habilitation in Erlangen, mentored by Paul von Ragué Schleyer, and was promoted to professor in 1980. Following a three-month visiting

• the very few chemists with a history of research and teaching in theoretical, organic and inorganic chemistry. His research interests combined all three fields, with a focus on homogeneous catalysis with transition metal complexes. Bidentate donor ligands with a small bite angle such as bis(di-tert

Synthesis and characterization of fluorinated azadipyrromethene complexes as acceptors for organic photovoltaics

• Forrest S. Etheridge,
• Roshan J. Fernando,
• Sandra Pejić,
• Matthias Zeller and
• Geneviève Sauvé

Beilstein J. Org. Chem. 2016, 12, 1925–1938, doi:10.3762/bjoc.12.182

• reduction potentials (more positive), allowed for air-stable fabrication of organic field effect transistors (OFETs), and showed promise in solar cells [13][32]. Some homoleptic metal complexes, such as Ir(III) phenylpyridine-based complexes, are favored for their use in light-emitting devices and the

Experimental and theoretical investigations on the high-electron donor character of pyrido-annelated N-heterocyclic carbenes

• Michael Nonnenmacher,
• Dominik M. Buck and
• Doris Kunz

Beilstein J. Org. Chem. 2016, 12, 1884–1896, doi:10.3762/bjoc.12.178

• to stabilize low coordinated metal fragments in higher oxidation states, for example intermediates of catalytic reactions. Experimental General information. All reactions were carried out under an inert argon atmosphere in dried and degassed solvents using standard Schlenk techniques. All metal

• complexes were handled in an MBraun glovebox with a nitrogen atmosphere. Solvents were dried according to standard procedures. [Rh(dipiy)Cl(cod)] (1a), [Rh(dipiytBu)Cl(cod)] (1b) [56] and the dipyridoimidazolium salt dipiytBu*HBF4 [41] were prepared according to literature procedures. NMR spectra were

TMSBr-mediated solvent- and work-up-free synthesis of α-2-deoxyglycosides from glycals

• Mei-Yuan Hsu,
• Yi-Pei Liu,
• Sarah Lam,
• Su-Ching Lin and
• Cheng-Chung Wang

Beilstein J. Org. Chem. 2016, 12, 1758–1764, doi:10.3762/bjoc.12.164

• -unsatuated glycosides. This constitutes the major competitive reaction pathway in acid-catalysed 2-deoxyglycosylation of glycals [52][57][59]. Besides, unfavourable conditions involving the use of expensive or toxic metal complexes, high temperatures, and long reaction times are usually required in most of

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

• . Finally, the decomposition of 62 gives esters 59a–f. A number of other modern oxidizing systems are based on transition metal-peroxo complexes. The use of transition metal complexes were also used as catalysts for the Baeyer–Villiger reaction and the first example was documented in 1978 [196][214]. For

• example, Mo(VI) peroxo complexes 64 and 65 were employed as the catalysts and 90% H2O2 served as the oxidizer (Table 5). The results obtained from the reactions using molybdenum systems have stimulated the search for new catalysts based on transition metal complexes. The usage of the platimum complex

• [(dppb}Pt(µ-OH)]22+, where dppb is butane-1,4-diylbis(diphenylphosphane) (Scheme 19) [208]. The oxidation mechanism of ketones 67 is displayed in Scheme 20. The use of variable-valence metal complexes opened up a new field of application of the Baeyer–Villiger oxidation and there are now dozens of

Ring-whizzing in polyene-PtL₂ complexes revisited

• Oluwakemi A. Oloba-Whenu,
• Thomas A. Albright and
• Chirine Soubra-Ghaoui

Beilstein J. Org. Chem. 2016, 12, 1410–1420, doi:10.3762/bjoc.12.135

• , octafluorooctatetraene, 6-radialene, pentalene, phenalenium+, naphthalene and octafluoronaphthalene. The HOMO of a d10 ML2 group (with b2 symmetry) interacting with the LUMO of the polyene was used as a model to explain the occurrence of minima and maxima on the potential energy surface. Keywords: d10 metal complexes

• ; density functional theory (DFT); hapototropic rearrangements; HOMO–LUMO interactions; polyene-ML2 complexes; ring-whizzing; Introduction Polyene–transition metal complexes were found to undergo fluxional rearrangements as early as 1956 with the preparation of Cp2Fe(CO)2 [1]. The migration of an MLn unit

• from 35, as well as, η1, 36, and η3, 37. Unfortunately none of these produced new stationary points. We will return to this Ni versus Pt issue later. C. Polycyclic examples Pentalene metal complexes have been the subject of a number of investigations [61], as well as, theoretical explorations of

On the mechanism of imine elimination from Fischer tungsten carbene complexes

• Philipp Veit,
• Christoph Förster and
• Katja Heinze

Beilstein J. Org. Chem. 2016, 12, 1322–1333, doi:10.3762/bjoc.12.125

• spectrum of W(CO)5(E-2) (Supporting Information File 1) is similar to that of Cr(CO)5(E-2) [27] and to those of carbene(pentacarbonyl)metal complexes (Cr, W) [60][61]. Thermolysis of W(CO)5(E-2) in refluxing toluene gives imine E-3 [43] after ca. 24 h in almost quantitative yield, as monitored by 1H NMR

Artificial Diels–Alderase based on the transmembrane protein FhuA

• Hassan Osseili,
• Daniel F. Sauer,
• Klaus Beckerle,
• Marcus Arlt,
• Tomoki Himiyama,
• Tino Polen,
• Akira Onoda,
• Ulrich Schwaneberg,
• Takashi Hayashi and
• Jun Okuda

Beilstein J. Org. Chem. 2016, 12, 1314–1321, doi:10.3762/bjoc.12.124

• metal complexes As the protein host, the FhuA ΔCVFtev variant of the Ferric hydroxamate uptake protein component A (FhuA) was chosen [31]. This protein was shown to be suitable to harbor Grubbs–Hoveyda type catalysts for olefin metathesis [17][18]. To anchor Cu(I) in the protein FhuA ΔCVFtev that

Synthesis, fluorescence properties and the promising cytotoxicity of pyrene–derived aminophosphonates

• Jarosław Lewkowski,
• Maria Rodriguez Moya,
• Anna Wrona-Piotrowicz,
• Janusz Zakrzewski,
• Renata Kontek and
• Gabriela Gajek

Beilstein J. Org. Chem. 2016, 12, 1229–1235, doi:10.3762/bjoc.12.117

• preliminary form [9], fluorescence emission of their azomethine precursors was reported for pyrene-1-carboxaldehyde thiosemicarbazone and Schiff bases as well as their metal complexes [16][17][18][19][20][21]. Such properties were described for, e.g., ruthenium(II) complexes of (5-chloropyridin-2-yl)-(pyren-1

Chiral cyclopentadienylruthenium sulfoxide catalysts for asymmetric redox bicycloisomerization

• Barry M. Trost,
• Michael C. Ryan and
• Meera Rao

Beilstein J. Org. Chem. 2016, 12, 1136–1152, doi:10.3762/bjoc.12.110

• relative to substrate. Diastereomeric metal complexes formed after alcohol coordination. Divergent behavior of the palladium and ruthenium-catalyzed Alder–ene reaction. Some asymmetric enyne cycloisomerization reactions. Synthesis of p-anisyl catalyst 1. Using norephedrine-based oxathiazolidine-2-oxide 7