Versatile deprotonated NHC: C,N-bridged dinuclear iridium and rhodium complexes

• Albert Poater

Beilstein J. Org. Chem. 2016, 12, 117–124, doi:10.3762/bjoc.12.13

• thousands of papers have presented and described the NHC based catalysis, bearing a carbene–metal coordination [7], catalytically few efforts have been dedicated to other types of coordination of the NHC with the metal. Braunstein and collaborators have smartly faced the challenge to mix the reactivity of

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

• of remotely functionalised ligands within the metal coordination sphere. A very efficient covalent immobilisation through anionic ligands was reported by Buchmeiser et al., who synthesised a series of monolith-supported catalysts (such as 1) which gave metathesis products with extremely low residual

Star-shaped tetrathiafulvalene oligomers towards the construction of conducting supramolecular assembly

• Masahiko Iyoda and
• Masashi Hasegawa

Beilstein J. Org. Chem. 2015, 11, 1596–1613, doi:10.3762/bjoc.11.175

• bonding, metal coordination, CT interaction, π···π stacking, van der Waals interaction, etc.) play an important role in the formation of the three-dimensional (3D) crystal structures [5]. For the construction of nanostructured objects, π···π, S···S, and other weak intermolecular interactions first

Ruthenium indenylidene “1^st generation” olefin metathesis catalysts containing triisopropyl phosphite

• Stefano Guidone,
• Fady Nahra,
• Alexandra M. Z. Slawin and
• Catherine S. J. Cazin

Beilstein J. Org. Chem. 2015, 11, 1520–1527, doi:10.3762/bjoc.11.166

• general, the commonly used Ru(II)-based pre-catalysts have five ligands in the metal coordination sphere and adopt a distorted square pyramidal geometry (Figure 1). The basic components of this structure include two L-type ligands mutually trans (e.g., phosphines and N-heterocyclic carbene) and two

Synthesis and characterization of the cyanobenzene-ethylenedithio-TTF donor

• Sandrina Oliveira,
• Dulce Belo,
• Isabel C. Santos,
• Sandra Rabaça and
• Manuel Almeida

Beilstein J. Org. Chem. 2015, 11, 951–956, doi:10.3762/bjoc.11.106

• unit to prepare new charge transfer salts where both the dipolar moment and the possibility of metal coordination and other interactions mediated by the cyano group can be further explored to obtain compounds with interesting properties. Experimental Materials and methods Elemental analyses of the

Self-assembly of heteroleptic dinuclear metallosupramolecular kites from multivalent ligands via social self-sorting

• Christian Benkhäuser and
• Arne Lützen

Beilstein J. Org. Chem. 2015, 11, 693–700, doi:10.3762/bjoc.11.79

• concepts [13], (iii) metal coordination specifics as pioneered by J.-M. Lehn with metal centers that prefer five-fold coordination [14], or (iv) charge-separation effects as utilized by P. J. Stang [15]. As part of our ongoing efforts to develop general guidelines for the (diastereo)selective self-assembly

• alkyne 11 in 96% yield [28]. Finally, a two-fold Sonogashira reaction with 1,3-diiodobenzene afforded the desired bis(2,2’-bipyridine) ligand 2 in quantitative yield. Metal coordination After the successful synthesis we prepared a DMSO solution of copper(I) ions, added it to the ligands (rac)-1 and 2

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

Phosphinocyclodextrins as confining units for catalytic metal centres. Applications to carbon–carbon bond forming reactions

• Matthieu Jouffroy,
• Rafael Gramage-Doria,
• David Sémeril,
• Dominique Armspach,
• Dominique Matt,
• Werner Oberhauser and
• Loïc Toupet

Beilstein J. Org. Chem. 2014, 10, 2388–2405, doi:10.3762/bjoc.10.249

• Mizoroki–Heck and asymmetric hydroformylation reactions. The related trans-chelating diphosphine WIDEPHOS (Figure 1) was also tested for comparison purposes in the case of the Mizoroki–Heck coupling studies. Results and Discussion Metal coordination As shown previously, HUGPHOS-1 and HUGPHOS-2 are able to

Towards allosteric receptors – synthesis of β-cyclodextrin-functionalised 2,2’-bipyridines and their metal complexes

• Christopher Kremer,
• Gregor Schnakenburg and
• Arne Lützen

Beilstein J. Org. Chem. 2014, 10, 814–824, doi:10.3762/bjoc.10.77

• was found to proceed smoothly in dry dichloromethane at room temperature to furnish the desired bis(cyclodextrin)-functionalised 2,2’-bipyridines 1, 2, and 3 in very good yields of 92, 93, and 86% yield, respectively (Scheme 5). Metal coordination – effector binding With our three cyclodextrin

Self-assembly of metallosupramolecular rhombi from chiral concave 9,9’-spirobifluorene-derived bis(pyridine) ligands

• Rainer Hovorka,
• Sophie Hytteballe,
• Torsten Piehler,
• Georg Meyer-Eppler,
• Filip Topić,
• Kari Rissanen,
• Marianne Engeser and
• Arne Lützen

Beilstein J. Org. Chem. 2014, 10, 432–441, doi:10.3762/bjoc.10.40

• second bis(pyridine) ligand (S)-6 in a two-fold Suzuki reaction. Metal coordination After the successful synthesis we mixed solutions of ligands 3 and 6 and [(dppp)Pd(OTf)2] or [(dppp)Pt(OTf)2] and characterised the resulting complexes by 1H, 31P, 1H 2D-DOSY NMR, ESI-MS, and single crystal X-ray

Intermediates in monensin biosynthesis: A late step in biosynthesis of the polyether ionophore monensin is crucial for the integrity of cation binding

• Wolfgang Hüttel,
• Jonathan B. Spencer and
• Peter F. Leadlay

Beilstein J. Org. Chem. 2014, 10, 361–368, doi:10.3762/bjoc.10.34

• also engaged in hydrogen bonding to the secondary alcohol borne at C-25, while the other carboxylate atom is engaged in an H-bond to the NH group of the urethane, thus maintaining the stability of the pseudocyclic structure [39]. The very different metal coordination pattern seen in dehydroxymonensin A

Silica: An efficient catalyst for one-pot regioselective synthesis of dithioethers

• Samir Kundu,
• Babli Roy and
• Basudeb Basu

Beilstein J. Org. Chem. 2014, 10, 26–33, doi:10.3762/bjoc.10.5

• food-processing industry [4][5][6][7][8]. For example, organosulfur compounds in garlic are often used in food-processing industries as flavouring and preservative agents and are also used as herbal medicine [4]. Dithioethers are commonly employed as ligands in preparing metal-coordination complexes

Advancements in the mechanistic understanding of the copper-catalyzed azide–alkyne cycloaddition

• Regina Berg and
• Bernd F. Straub

Beilstein J. Org. Chem. 2013, 9, 2715–2750, doi:10.3762/bjoc.9.308

Spin state switching in iron coordination compounds

• Philipp Gütlich,
• Ana B. Gaspar and
• Yann Garcia

Beilstein J. Org. Chem. 2013, 9, 342–391, doi:10.3762/bjoc.9.39

Design and synthesis of quasi-diastereomeric molecules with unchanging central, regenerating axial and switchable helical chirality via cleavage and formation of Ni(II)–O and Ni(II)–N coordination bonds

• Vadim A. Soloshonok,
• José Luis Aceña,
• Hisanori Ueki and
• Jianlin Han

Beilstein J. Org. Chem. 2012, 8, 1920–1928, doi:10.3762/bjoc.8.223

• assumed that the pentadentate ligand 4 upon coordination with d8 metals will give rise to tetra-coordinated square-planar complexes 5 and 6. The presence of coordinated and noncoordinated groups A and E, positioned up or down relative to the metal coordination plane, will create an element of axial

Azobenzene dye-coupled quadruply hydrogen-bonding modules as colorimetric indicators for supramolecular interactions

• Yagang Zhang and
• Steven C. Zimmerman

Beilstein J. Org. Chem. 2012, 8, 486–495, doi:10.3762/bjoc.8.55

• ]. Noncovalent hydrogen bonding, electrostatic interactions, π–π stacking and metal coordination have been used alone and in concert to assemble a broad range of building blocks, from small molecules [4][5][6][7] to polymers [8][9] including dendrimers [10][11]. Among these noncovalent interactions, hydrogen

Self-assembly of Ru₄ and Ru₈ assemblies by coordination using organometallic Ru(II)₂ precursors: Synthesis, characterization and properties

• Sankarasekaran Shanmugaraju,
• Dipak Samanta and
• Partha Sarathi Mukherjee

Beilstein J. Org. Chem. 2012, 8, 313–322, doi:10.3762/bjoc.8.34

• energy region compared to those of the starting acceptors (1a, νCO = 1623.7 cm−1; 1b, νCO = 1605.0 cm−1) due to the ligand-to-metal coordination. The appearance of a single peak in the 19F NMR spectrum at −81.03 ppm (2a) or −79.8 ppm (2b) indicated the presence of triflate counter anions in the same

• δ 5.14–5.81 ppm. Notably, the 1H signals of the protons of L exhibited a significant downfield shift compared to the unbound linker due to the loss of electron density upon ligand-to-metal coordination (Figure 1 and Figure S2, Supporting Information File 1). The high solubility of the assemblies in

• common organic solvents and the symmetric nature of 1H NMR spectra primarily ruled out the formation of a polymer with extended coordination. Although the initial characterization of the self-assembled species by NMR spectroscopy intimated the ligand-to-metal coordination, it does not provide any

Fifty years of oxacalix[3]arenes: A review

• Kevin Cottet,
• Paula M. Marcos and
• Peter J. Cragg

Beilstein J. Org. Chem. 2012, 8, 201–226, doi:10.3762/bjoc.8.22

• + preferentially interacts with them across the ring. Introduction of heteroatoms, such as nitrogen, into the oxacalix[3]arene lower rims can also be achieved by O-alkylation. Pyridine is known to be a good ligand towards metals and is widely employed in transition-metal coordination chemistry; therefore, in an

Thermodynamic and kinetic stabilization of divanadate in the monovanadate/divanadate equilibrium using a Zn-cyclene derivative: Towards a simple ATP synthase model

• Hanno Sell,
• Anika Gehl,
• Frank D. Sönnichsen and
• Rainer Herges

Beilstein J. Org. Chem. 2012, 8, 81–89, doi:10.3762/bjoc.8.8

• . catalyzed the condensation of acetyl phosphate and phosphate to pyrophosphate using a protonated macrocyclic polyamine [17][18][19]. Results and Discussion Investigation of the thermodynamic effect To investigate the fundamental thermodynamic and kinetic effects of metal coordination in inorganic

• artificial system driving endergonic condensations (Figure 1), we draw the conclusion that only one of the binding sites should provide metal coordination to the vanadate (or phosphate) and the other binding site should associate the nucleophilic anion by neutral hydrogen bonds. Similar effects obviously

• given in Å. Metal coordination as well as H–bond formation are operative in binding the oxo-anion to the zinc cyclene unit. The schematic representation (right) is used to improve clarity. 51V NMR titration at pH 9.5 ([V]t = 1.5 mM, [1]t = 0 to 7.5 mM (0 to 5 equiv), 100 mM CHES). [V]t and [1]t are the

Redox-active tetrathiafulvalene and dithiolene compounds derived from allylic 1,4-diol rearrangement products of disubstituted 1,3-dithiole derivatives

• Filipe Vilela,
• Peter J. Skabara,
• Christopher R. Mason,
• Thomas D. J. Westgate,
• Asun Luquin,
• Simon J. Coles and
• Michael B. Hursthouse

Beilstein J. Org. Chem. 2010, 6, 1002–1014, doi:10.3762/bjoc.6.113

• route for the synthesis and functionalisation of sulfur rich compounds including redox active compounds of TTFs, and a Ni dithiolene. Keywords: aldehydes; metal-coordination; rearrangement; sulfur heterocycles; tetrathiafulvalene; Introduction The search for novel structures derived from TTF has led

• expand this family of compounds. For example, previous work has shown that the electron-donating ability of terthiophenes can be tailored by this approach [30][31]. Also, the metal-coordination properties of the dithiolate anion, as shown in compound 28, present a potentially rich avenue for further

The subtle balance of weak supramolecular interactions: The hierarchy of halogen and hydrogen bonds in haloanilinium and halopyridinium salts

• Kari Raatikainen,
• Massimo Cametti and
• Kari Rissanen

Beilstein J. Org. Chem. 2010, 6, No. 4, doi:10.3762/bjoc.6.4

• engineering; halogen bonding; hydrogen bonding; supramolecular chemistry; weak interactions; Introduction Non-covalent interaction, such as hydrogen bonding and metal coordination represent the basic set of tools for the construction of elaborate architectures in the supramolecular chemistry of organic or

An enantiomerically pure siderophore type ligand for the diastereoselective 1 : 1 complexation of lanthanide(III) ions

• Markus Albrecht,
• Olga Osetska,
• Thomas Abel,
• Gebhard Haberhauer and
• Eva Ziegler

Beilstein J. Org. Chem. 2009, 5, No. 78, doi:10.3762/bjoc.5.78

• as CD spectroscopic titrations in methanol together with NaOH as base (10−4 M; Figure 4). Upon coordination of the metal ions to the ligand the transitions at the aromatic unit are influenced leading to changes in the UV–vis spectrum. In addition, metal coordination restricts the conformation at the

Functional properties of metallomesogens modulated by molecular and supramolecular exotic arrangements

• Alessandra Crispini,
• Mauro Ghedini and
• Daniela Pucci

Beilstein J. Org. Chem. 2009, 5, No. 54, doi:10.3762/bjoc.5.54

• single molecule to supramolecular network, confirming that metal coordination provides a helpful tool for obtaining multifunctional soft materials. Keywords: coordination complexes; functionality; liquid crystals; metallomesogens; Introduction Recent interest in designing novel soft and functional