Synthesis of non-racemic 4-nitro-2-sulfonylbutan-1-ones via Ni(II)-catalyzed asymmetric Michael reaction of β-ketosulfones

• Alexander N. Reznikov,
• Anastasiya E. Sibiryakova,
• Marat R. Baimuratov,
• Eugene V. Golovin,
• Victor B. Rybakov and
• Yuri N. Klimochkin

Beilstein J. Org. Chem. 2019, 15, 1289–1297, doi:10.3762/bjoc.15.127

• transition metal complexes. The preparation of hydroxy sulfones from β-ketosulfones in the presence of Ru [19][20], Ir [21] and Rh [22] complexes was described. Chiral sulfones were also obtained by hydrogenation of the C=C bond with α,β-unsaturated sulfones in the presence of Ir(I) complexes with P,N

• ketosulfones with nitroalkenes in the presence of organocatalysts shows high enantioselectivity, however, leads to a mixture of diastereomers. For the catalytic activation of β-ketosulfones by metal complexes chiral Lewis acids may be considered as an alternative way to carry out the asymmetric Michael

• the absolute configuration as compared to the analogous adamantyl derivative, which will be discussed below. It should be noted that low diastereoselectivity was previously observed in the asymmetric addition of various Michael donors to nitroalkenes in the presence of both metal complexes [47] and

Design of a double-decker coordination cage revisited to make new cages and exemplify ligand isomerism

• Sagarika Samantray,
• Sreenivasulu Bandi and
• Dillip K. Chand

Beilstein J. Org. Chem. 2019, 15, 1129–1140, doi:10.3762/bjoc.15.109

• positional isomer or regioisomer of L2) in order to exemplify ligand isomerism. Ligand isomerism includes metal complexes (at least two) having the same molecular formula but are composed of different positional isomers (regioisomers) of the ligand. Positional isomers (regioisomers) of a non-chelating ligand

• complexes of L1 versus L2: ligand isomerism phenomenon As discussed in the introduction section “The definition of ligand isomerism includes metal complexes (at least two) having the same molecular formula but are composed of different structural isomers of the ligand.” The complexes prepared in this work

Precious metal-free molecular machines for solar thermal energy storage

• Meglena I. Kandinska,
• Snejana M. Kitova,
• Vladimira S. Videva,
• Stanimir S. Stoyanov,
• Stanislava B. Yordanova,
• Stanislav B. Baluschev,
• Silvia E. Angelova and
• Aleksey A. Vasilev

Beilstein J. Org. Chem. 2019, 15, 1096–1106, doi:10.3762/bjoc.15.106

• constants of metal complexes were determined and are in good agreement with the literature data for reference dyes. The temporal evolution of trans-to-cis isomerization was observed in a real-time regime. The dyes demonstrated a low intrinsic fluorescence of their Ba2+ complexes and high yield of E/Z

Mechanochemistry of supramolecules

• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2019, 15, 881–900, doi:10.3762/bjoc.15.86

• ]. Subsequently, compound 2 underwent substitution with α,α’-dibromo-o-xylene to create the nickel(II) complex 3 [54]. In 2014, James and co-workers reported a one-pot two-step mechanochemical synthesis of metal complexes 7 (Figure 3). First, the salen-type ligand 6 was synthesized from o-hydroxybenzaldehyde (4

Coordination chemistry and photoswitching of dinuclear macrocyclic cadmium-, nickel-, and zinc complexes containing azobenzene carboxylato co-ligands

• Jennifer Klose,
• Tobias Severin,
• Peter Hahn,
• Alexander Jeremies,
• Jens Bergmann,
• Daniel Fuhrmann,
• Jan Griebel,
• Bernd Abel and
• Berthold Kersting

Beilstein J. Org. Chem. 2019, 15, 840–851, doi:10.3762/bjoc.15.81

• , SQUID magnetometry and X-ray crystallography is reported herein. Preliminary results concerning the photoisomerization of compound 1 are reported as well. Results and Discussion Synthesis of ligands and metal complexes Scheme 1 shows the synthetic procedures. The yellow-orange colored zinc complexes (3

• of metal complexes”) is gratefully acknowledged.

Synthesis of polydicyclopentadiene using the Cp₂TiCl₂/Et₂AlCl catalytic system and thin-layer oxidation of the polymer in air

• Zhargolma B. Bazarova,
• Ludmila S. Soroka,
• Alex A. Lyapkov,
• Мekhman S. Yusubov and
• Francis Verpoort

Beilstein J. Org. Chem. 2019, 15, 733–745, doi:10.3762/bjoc.15.69

• interaction of organometallic transition metal complexes with organic aluminum compounds. The formation of such unstable bis(cyclopentadienyl)titanium dichloride complexes with a Ti=CHR fragment is possible as well in this case. The obtained complex is polarized in such a way that the metal has a positive

Selective benzylic C–H monooxygenation mediated by iodine oxides

• Kelsey B. LaMartina,
• Haley K. Kuck,
• Linda S. Oglesbee,
• Asma Al-Odaini and
• Nicholas C. Boaz

Beilstein J. Org. Chem. 2019, 15, 602–609, doi:10.3762/bjoc.15.55

• dyes and transition metal complexes, hypohalous acids, and persulfate anions [12][34][35][36][37][38][39][40]. An important class of catalyzed benzylic C–H to C–O transformations are those catalyzed by N-oxyl radicals. Specifically, N-oxyl radical catalysts based upon the N-hydroxyphthalimide (NHPI

Microwave-assisted synthesis of N,N-bis(phosphinoylmethyl)amines and N,N,N-tris(phosphinoylmethyl)amines bearing different substituents on the phosphorus atoms

• Erika Bálint,
• Anna Tripolszky,
• László Hegedűs and
• György Keglevich

Beilstein J. Org. Chem. 2019, 15, 469–473, doi:10.3762/bjoc.15.40

• )amines; Introduction α-Aminophosphine oxides are of considerable importance as potential precursors of α-aminophosphine ligands [1]. α-Aminophosphines play an important role in the synthesis of P(III)-transition metal complexes [2], which are often applied catalysts in homogeneous catalytic reactions [2

Aqueous olefin metathesis: recent developments and applications

• Valerio Sabatino and
• Thomas R. Ward

Beilstein J. Org. Chem. 2019, 15, 445–468, doi:10.3762/bjoc.15.39

• multiple tedious steps, primarily because metal complexes’ impurities in the final product may cause isomerization or decomposition of the products and may be toxic. The latter is a very critical issue for the pharmaceutical industry, as the amount of ruthenium in APIs (active pharmaceutical ingredients

Reusable and highly enantioselective water-soluble Ru(II)-Amm-Pheox catalyst for intramolecular cyclopropanation of diazo compounds

• Hamada S. A. Mandour,
• Yoko Nakagawa,
• Masaya Tone,
• Hayato Inoue,
• Nansalmaa Otog,
• Ikuhide Fujisawa,
• Soda Chanthamath and
• Seiji Iwasa

Beilstein J. Org. Chem. 2019, 15, 357–363, doi:10.3762/bjoc.15.31

• diazoamide; Ru(II)-Pheox; water-soluble catalyst; Weinreb amide; Introduction Water-soluble transition metal complexes have been attracting increasing interest for catalytic applications because of their many advantages such as simple product separation, low cost, safety, and environmentally friendly

Gold-catalyzed ethylene cyclopropanation

• Silvia G. Rull,
• Andrea Olmos and
• Pedro J. Pérez

Beilstein J. Org. Chem. 2019, 15, 67–71, doi:10.3762/bjoc.15.7

• = tetrakis(3,5-bis(trifluoromethyl)phenyl)borate) catalyzes the ethylene cyclopropanation with ethyl diazoacetate as the carbene precursor, under mild conditions, with moderate yields (ca. 70%, EDA-based). Results and Discussion Diazo compounds N2=CRR’ usually react with metal complexes of groups 8–11 with

Organometallic vs organic photoredox catalysts for photocuring reactions in the visible region

• Aude-Héloise Bonardi,
• Frédéric Dumur,
• Guillaume Noirbent,
• Jacques Lalevée and
• Didier Gigmes

Beilstein J. Org. Chem. 2018, 14, 3025–3046, doi:10.3762/bjoc.14.282

• Figure 3. Absorption band observable are very intense. 1.3.5 Metal to ligand charge transfer (MLCT): The MLCT transition is a second type of charge transfer observed with metal complexes. More particularly, it is observed for complexes whose ligands have relatively high-energy lone pairs or in case of

• photoredox catalysts The first photoredox catalysts to emerge were the metal-based complexes. Indeed, metal complexes, also named coordination compounds, have been recognized in the photochemistry field since the second half of the last century [33][34][35]. However, these compounds are still the subject of

• of the ligand is essential for good properties. 2.1.3 The latest generation of metal-based catalysts: Emergence of the TADF complexes: Metal complexes are still at the origin of numerous researches as photoredox catalysts, these researches being notably motivated by their remarkable long-lived

Reactions of 3-(p-substituted-phenyl)-5-chloromethyl-1,2,4-oxadiazoles with KCN leading to acetonitriles and alkanes via a non-reductive decyanation pathway

• Akın Sağırlı and
• Yaşar Dürüst

Beilstein J. Org. Chem. 2018, 14, 3011–3017, doi:10.3762/bjoc.14.280

• ], transition metal complexes [25], and alkali metals in a variety of solvents [26]. Generally, they require mostly an inert atmosphere as well as harsh reaction conditions. These facts constitute challenges to the development of mild reaction conditions in the reduction of nitrilated compounds. In the light of

The influence of the cationic carbenes on the initiation kinetics of ruthenium-based metathesis catalysts; a DFT study

• Magdalena Jawiczuk,
• Angelika Janaszkiewicz and
• Bartosz Trzaskowski

Beilstein J. Org. Chem. 2018, 14, 2872–2880, doi:10.3762/bjoc.14.266

• either anionic or cationic carbenes [15][16][17][18]. Cationic ligands with a positive charge close to the coordinating atom are relatively rare, as their coordination ability of transition metals, bearing also a formal positive charge, is weakened. Nevertheless, stable metal complexes with cationic

• recently and examples of their transition metal complexes are scarce. In 2013 Ganter described a cationic NHC with a fused pyridinium moiety and the formal +1 charge just one bond away from the imidazole core [27]. In 2017 César synthesized a cationic imidazolylidene NHC with an ammonium tag attached

• interesting phenomenon, despite its very limited impact on their propensity to form transition metal complexes (Scheme 2) [50]. Many works have been devoted to the study of carbene dimerization and present evidence that mechanism of monomer–dimer equilibrium depends on the balance between the electronic and

Olefin metathesis catalysts embedded in β-barrel proteins: creating artificial metalloproteins for olefin metathesis

• Daniel F. Sauer,
• Johannes Schiffels,
• Takashi Hayashi,
• Ulrich Schwaneberg and
• Jun Okuda

Beilstein J. Org. Chem. 2018, 14, 2861–2871, doi:10.3762/bjoc.14.265

• [50]. Further mutations within the cavity of NB provide a hydrophobic cavity. Several studies reported on the utilization of NB as scaffold for incorporated metal complexes, including the work of Hayashi et al. capitalizing on the polymerization of phenylacetylene [50][51], the Diels–Alder reaction

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

• developed based on well-defined metal complexes such as metalloporphyrins and metal–salen complexes [15][16][17][18][19][20][21]. In parallel to the development of catalysts, new polyester materials also were prepared by employing unprecedented monomers or by the combination with other polymerization

• -workers reported that the dinuclear chromium–salan complex showed a much higher catalytic activity than the corresponding mononuclear chromium–salan complex in the copolymerization of epoxides with maleic anhydride (MA) [31]. Following this report, some dinuclear metal complexes have been reported to

• catalytic activity than the corresponding mononuclear cobalt–salen complex. These results indicate that the design based on di- or multinuclear metal complexes is a promising strategy for the development of highly active catalysts. Our future studies will focus on the optimization of linker structures as

DABCO- and DBU-promoted one-pot reaction of N-sulfonyl ketimines with Morita–Baylis–Hillman carbonates: a sequential approach to (2-hydroxyaryl)nicotinate derivatives

• Soumitra Guin,
• Raman Gupta,
• Debashis Majee and
• Sampak Samanta

Beilstein J. Org. Chem. 2018, 14, 2771–2778, doi:10.3762/bjoc.14.254

• products [4], medicines [5], chelating agents in transition metal complexes [6][7], and material science [8][9]. Pyridine derivatives such as vitamins B6, B3 (niacin), and nicotinamide adenine dinucleotide (NAD) play a significant role in the metabolism process of living organisms. Consequently, many

Transition metal-free oxidative and deoxygenative C–H/C–Li cross-couplings of 2H-imidazole 1-oxides with carboranyl lithium as an efficient synthetic approach to azaheterocyclic carboranes

• Lidia A. Smyshliaeva,
• Mikhail V. Varaksin,
• Pavel A. Slepukhin,
• Oleg N. Chupakhin and
• Valery N. Charushin

Beilstein J. Org. Chem. 2018, 14, 2618–2626, doi:10.3762/bjoc.14.240

• capture therapy (BNCT) of cancer [8][9][10][11][12], as well as agonists and antagonists of biological receptors [13][14][15][16][17], etc. In addition, azaheterocyclic carboranes are actively used as ligands in the synthesis of metal complexes of various architectures, possessing catalytic activity [18

Efficient catalytic alkyne metathesis with a fluoroalkoxy-supported ditungsten(III) complex

• Henrike Ehrhorn,
• Janin Schlösser,
• Dirk Bockfeld and
• Matthias Tamm

Beilstein J. Org. Chem. 2018, 14, 2425–2434, doi:10.3762/bjoc.14.220

• cleaving the W≡W bond in W2F3 with 1-phenyl-1-propyne. The catalytic alkyne metathesis activity of these metal complexes was determined in the self-metathesis, ring-closing alkyne metathesis and cross-metathesis of internal and terminal alkynes, revealing an almost equally high metathesis activity for the

Non-metal-templated approaches to bis(borane) derivatives of macrocyclic dibridgehead diphosphines via alkene metathesis

• Tobias Fiedler,
• Michał Barbasiewicz,
• Michael Stollenz and
• John A. Gladysz

Beilstein J. Org. Chem. 2018, 14, 2354–2365, doi:10.3762/bjoc.14.211

• ; crystal structures; homeomorphic isomerization; hydrogenation; in/out isomers; metathesis; phosphine boranes; Introduction We have found that a variety of metal complexes with trans-phosphine ligands of the formula P((CH2)mCH=CH2)3 (1; m = 4–14) undergo threefold interligand ring closing alkene

• metatheses to give, after hydrogenations, metal complexes of in,in isomers of macrocyclic dibridgehead diphosphines [1][2][3][4][5][6][7][8][9][10][11][12][13]. Representative examples with square planar complexes are shown in Scheme 1. Analogous sequences with trigonal bipyramidal substrates proceed in

• an isomer below. A white powder was obtained next. The 13C{1H} NMR spectrum exhibited fourteen signals, half of which were approximately twice as intense as the others. Two signals of each set exhibited phosphorus coupling. The overall pattern was quite similar to those shown by metal complexes with

D-Fructose-based spiro-fused PHOX ligands: synthesis and application in enantioselective allylic alkylation

• Michael R. Imrich,
• Jochen Kraft,
• Cäcilia Maichle-Mössmer and
• Thomas Ziegler

Beilstein J. Org. Chem. 2018, 14, 2082–2089, doi:10.3762/bjoc.14.182

• -fused PHOX ligands. The described ligands can be prepared from literature-known carbohydrate derivatives in two steps. Preliminary tests of the spiro-fused PHOX ligands in Tsuji–Trost reaction showed promising results. Different metal complexes as well as further application of the ligands in asymmetric

Graphitic carbon nitride prepared from urea as a photocatalyst for visible-light carbon dioxide reduction with the aid of a mononuclear ruthenium(II) complex

• Kazuhiko Maeda,
• Daehyeon An,
• Ryo Kuriki,
• Daling Lu and
• Osamu Ishitani

Beilstein J. Org. Chem. 2018, 14, 1806–1812, doi:10.3762/bjoc.14.153

• phase. Keywords: artificial photosynthesis; heterogeneous photocatalysis; hybrid material; metal complexes; solar fuels; Introduction Carbon nitride is one of the oldest synthetic polymers [1], and has several allotropes. Among them, graphitic carbon nitride (g-C3N4) is the most stable form and is an

• reduction systems using g-C3N4-based materials, in combination with functional metal complexes [8][9][10][11][12][13][14][15][16]. For example, mesoporous g-C3N4 (mpg-C3N4) modified with a mononuclear Ru(II) complex, such as trans-(Cl)-Ru{(PO3H2)2bpy(CO)2Cl2} (bpy: 2,2’-bipyridine), abbreviated as RuP, is

• using cobalt-based metal complexes as reduction cocatalysts [17][18][19][20]. In these systems, structural properties of g-C3N4 such as specific surface area and porosity have a strong impact on activity, because they strongly affect the efficiency of electron/hole utilization to the surface chemical

DFT calculations on the mechanism of copper-catalysed tandem arylation–cyclisation reactions of alkynes and diaryliodonium salts

• Tamás Károly Stenczel,
• Ádám Sinai,
• Zoltán Novák and
• András Stirling

Beilstein J. Org. Chem. 2018, 14, 1743–1749, doi:10.3762/bjoc.14.148

• route often observed for the 16 electron metal complexes. We could locate a crucial structure (Ic) where the incoming reactant and the leaving solvent molecule occupy the equatorial position of the trigonal bipyramid formed by the five ligands of the Cu(III) ion. We decided to characterise this step by

Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis

• Gwendal Grelier,
• Benjamin Darses and
• Philippe Dauban

Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128

• for the 1,2-benzoyloxy-azidation reaction. Based on a preliminary observation made during their study on catalytic trifluoromethylation of enamides [49], the group of Gillaizeau has reported the catalytic conversion of enamides with various ABX derivatives 44 [50]. A screening of various metal

• complexes has led the authors to demonstrate the superior ability of cheap FeCl2 to mediate the 1,2-addition thereby allowing the formation of the trans-products 43 with complete regio- and diastereocontrol (Scheme 14). The group of Hamashima has reported that various 1,2-difunctionalizations of alkenes can

Recent advances in phosphorescent platinum complexes for organic light-emitting diodes

• Cristina Cebrián and
• Matteo Mauro

Beilstein J. Org. Chem. 2018, 14, 1459–1481, doi:10.3762/bjoc.14.124

• organometallic compounds based on heavy transition metal complexes (TMCs) are an appealing research topic of enormous current interest. Amongst all different fields in which they found valuable application, development of emitting materials based on TMCs have become crucial for electroluminescent devices such as