Synthesis of chiral 3-substituted 3-amino-2-oxindoles through enantioselective catalytic nucleophilic additions to isatin imines

• Hélène Pellissier

Beilstein J. Org. Chem. 2018, 14, 1349–1369, doi:10.3762/bjoc.14.114

• ]. An extensively used two-component variant of this reaction consists in using a preformed imine. Among chiral metal complexes, a wide variety of organocatalysts [26][27][28][29][30][31][32][33][34] has been used to promote asymmetric Mannich reactions. Among them, cinchona alkaloid 1 was employed in

• either chiral organocatalysts or chiral metal complexes. Among the organocatalysts, chiral bifunctional guanidine 50 was applied by Feng et al. in 2015 to promote the reaction of nitromethane 51 with N-Boc-isatin imines 3 (Scheme 18) [71]. The reaction performed at −30 °C using 10 mol % of this catalyst

• trimethylsilyl ether. However, also metal complexes (Zn, Sn) derived from N,N’-dioxide and BINOL-derived ligands have been employed affording the products with enantioselectivities of up to 90–99% ee. Moreover, comparable enantioselectivities of up to 99% ee were reported in aza-Morita–Baylis–Hilman reactions

Selective carboxylation of reactive benzylic C–H bonds by a hypervalent iodine(III)/inorganic bromide oxidation system

• Toshifumi Dohi,
• Shohei Ueda,
• Kosuke Iwasaki,
• Yusuke Tsunoda,
• Koji Morimoto and
• Yasuyuki Kita

Beilstein J. Org. Chem. 2018, 14, 1087–1094, doi:10.3762/bjoc.14.94

• reaction systems have been further elaborated to include elegant C–H coupling methodologies. Several important researches that provide a new benzylic C–H coupling strategy have been reported over the past few years, involving the promising catalytic activities of metal complexes [13][14]. On the other hand

An overview of recent advances in duplex DNA recognition by small molecules

• Sayantan Bhaduri,
• Nihar Ranjan and
• Dev P. Arya

Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93

• exceptionally stable duplexes (ΔTm = +44.8 °C) and high selectivity [92]. Six novel 4-aminoantipyrine derived Schiff bases and their metal complexes with Cu(II), Ni(II), Zn(II) ions (conjugates 26–31) were synthesized and characterized and binding of these complexes with ct-DNA were analyzed by electronic

Phosphodiester models for cleavage of nucleic acids

• Satu Mikkola,
• Tuomas Lönnberg and
• Harri Lönnberg

Beilstein J. Org. Chem. 2018, 14, 803–837, doi:10.3762/bjoc.14.68

An uracil-linked hydroxyflavone probe for the recognition of ATP

• Márton Bojtár,
• Péter Zoltán Janzsó-Berend,
• Dávid Mester,
• Dóra Hessz,
• Mihály Kállay,
• Miklós Kubinyi and
• István Bitter

Beilstein J. Org. Chem. 2018, 14, 747–755, doi:10.3762/bjoc.14.63

• ], metal-complexes [21][22][23][24][25][26][27] and other direct sensing systems [28][29][30] have significant advantages over the classical, separation-based methods. The primary difficulties in the design of an ATP chemosensor are the structural similarity of ATP to other nucleotides (i.e., to guanosine

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• yield and output [23][24]. Indeed, such a strategy proved to be advantageous for performing reactions in water and minimizing both reaction waste and cost [25][26]. Attempts to support homogeneous metal complexes onto organic or inorganic surfaces to facilitate their removal/extraction from the reaction

AuBr₃-catalyzed azidation of per-O-acetylated and per-O-benzoylated sugars

• Jayashree Rajput,
• Srinivas Hotha and
• Madhuri Vangala

Beilstein J. Org. Chem. 2018, 14, 682–687, doi:10.3762/bjoc.14.56

• -benzoylated disaccharides needed 2–3 h of heating at 55 °C. Keywords: acylated sugars; azidation; gold(III) bromide; N-glycoside; oxophilicity; Introduction The past few decades had seen the enrichment of transition metal complexes in various glycosylation strategies [1]. In particular, gold complexes with

Recent advances on organic blue thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs)

• Thanh-Tuân Bui,
• Fabrice Goubard,
• Malika Ibrahim-Ouali,
• Didier Gigmes and
• Frédéric Dumur

Beilstein J. Org. Chem. 2018, 14, 282–308, doi:10.3762/bjoc.14.18

• % for phosphorescent OLEDs [5]. As drawback, triplet emitters are transition-metal complexes mostly based on iridium, platinum and osmium and the scarcity of these metals on Earth, their toxicity and high cost make these materials unsuitable candidates for a mass-production of OLEDs [6]. However

• and triplet excitons for radiative transition, excepted that the emission occurs from the singlet state and not from the triplet state (as observed for metal complexes) and that the triplet–triplet annihilation commonly observed with phosphorescent OLEDs [10] can be drastically reduced (see Figure 1

Synthesis and spectroscopic properties of β-meso directly linked porphyrin–corrole hybrid compounds

• Baris Temelli and
• Hilal Kalkan

Beilstein J. Org. Chem. 2018, 14, 187–193, doi:10.3762/bjoc.14.13

• used to obtain this product. In order to expand the scope of the reaction, metal complexes of formylated porphyrins were subjected to the reaction. While Zn-porphyrin containing hybrid compound 4f was isolated in 21%, the Cu(II) complex of β-formylated porphyrin underwent the reaction to produce the

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