Amino- and polyaminophthalazin-1(2H)-ones: synthesis, coordination properties, and biological activity

• Zbigniew Malinowski,
• Emilia Fornal,
• Agata Sumara,
• Renata Kontek,
• Karol Bukowski,
• Beata Pasternak,
• Dariusz Sroczyński,
• Joachim Kusz,
• Magdalena Małecka and
• Monika Nowak

Beilstein J. Org. Chem. 2021, 17, 558–568, doi:10.3762/bjoc.17.50

• the coordination of the amine takes place after the oxidative addition of the organic halide to the palladium–ligand complex. Based on the analysis of our results we have concluded that in the case of systems 3, the order of reagent addition could have a significant impact on a proper course of the

• 77% yield. Moreover, it turned out that this amination reaction also proceeded with a reduced amount of Pd2(dba)3 from 15 mol % to 2 mol % without loss of the product yield. These results showed that the coordination of the amine to the (BINAP)Pd complex probably leads to the formation of a (BINAP)Pd

• behavior of aminophthalazinones with Cu(II) ions To conclude the synthetic research, we looked at the potential of aminophthalazinones as polydentate ligands for the synthesis of complexes with metal ions. Examples of the use of phthalazinone and its derivatives in the synthesis of coordination compounds

Metal-free visible-light-enabled vicinal trifluoromethyl dithiolation of unactivated alkenes

• Xiaojuan Li,
• Qiang Zhang,
• Weigang Zhang,
• Jinzhu Ma,
• Yi Wang and
• Yi Pan

Beilstein J. Org. Chem. 2021, 17, 551–557, doi:10.3762/bjoc.17.49

• Xiaojuan Li Qiang Zhang Weigang Zhang Jinzhu Ma Yi Wang Yi Pan State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, and Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University

Annulation of a 1,3-dithiole ring to a sterically hindered o-quinone core. Novel ditopic redox-active ligands

• Sergey V. Norkov,
• Anton V. Cherkasov,
• Andrey S. Shavyrin,
• Maxim V. Arsenyev,
• Viacheslav A. Kuropatov and
• Vladimir K. Cherkasov

Beilstein J. Org. Chem. 2021, 17, 273–282, doi:10.3762/bjoc.17.26

• State University, 23 Gagarin Ave, 603950, Nizhny Novgorod, Russia 10.3762/bjoc.17.26 Abstract The fused 1,3-dithiole spacer seems to be very suitable for the functionalization of sterically hindered o-quinones with additional groups capable of coordination of metal ions and/or possessing a redox

• ligand; 1,3-dithiole; ditopic ligand; o-quinone; thiete; Introduction There are a number of methods which may be used for the synthesis of new o-quinones in order to vary their redox properties and coordination abilities. The key features of o-quinones are redox activity as well as chelating

• coordination ability. The redox state of o-quinone (semiquinone or catechol) could be changed both as free species or when it is coordinated to a metal ion as a ligand. Thus, the redox isomerism phenomenon was reported for o-quinone complexes with both transition and non-transition metals [1][2][3]. The

Au(III) complexes with tetradentate-cyclam-based ligands

• Ann Christin Reiersølmoen,
• Thomas N. Solvi and
• Anne Fiksdahl

Beilstein J. Org. Chem. 2021, 17, 186–192, doi:10.3762/bjoc.17.18

• -membered chelate rings. The testing of the catalytic ability of the cyclam-based N,N,N,N-Au(III) complexes demonstrated high catalytic activity of some complexes in selected test reactions (full conversion in 1–24 h, 62–97% product yields). Keywords: Au(III); carboalkoxylation; coordination studies

• ]. In contrast, gold(III) catalysis was for a long time mostly based on inorganic salts, such as AuCl3, AuBr3, or pyridine–AuCl3 and Pic–AuCl2. However, Au(III) complexes with various coordinated ligands are about to become more explored. Different from the linear coordination mode of gold(I), gold(III

• ) forms square planar complexes. This allows for greater steric control around the reaction center by using polydentate ligands. An interesting group of ligands which may coordinate to all the four coordination sites of gold(III), are represented by polyamine ligands, such as cyclam (1,4,8,11

Insight into functionalized-macrocycles-guided supramolecular photocatalysis

• Minzan Zuo,
• Krishnasamy Velmurugan,
• Kaiya Wang,
• Xueqi Tian and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2021, 17, 139–155, doi:10.3762/bjoc.17.15

• different Ti–S coordination modes between H4TC4A–Ti4 and H4TC4A–Ti6 result in different photocatalytic activities. The H2 evolution of H4TC4A–Ti4 was almost 5 times that of H4TC4A–Ti6 (73.56 μmol⋅g−1⋅h−1 vs 15.16 μmol⋅g−1⋅h−1). This work emphasized the importance of structure–efficiency relationships of

Molecular basis for protein–protein interactions

• Brandon Charles Seychell and
• Tobias Beck

Beilstein J. Org. Chem. 2021, 17, 1–10, doi:10.3762/bjoc.17.1

• containers in vitro. These highly charged variants were then used to form a binary three-dimensional assembly analogous to inorganic salts. The structure of this assembly was determined to have a 1:1 stoichiometry, with a coordination number of 12. The advantage of such systems was discussed to be that each

Pentannulation of N-heterocycles by a tandem gold-catalyzed [3,3]-rearrangement/Nazarov reaction of propargyl ester derivatives: a computational study on the crucial role of the nitrogen atom

• Giovanna Zanella,
• Martina Petrović,
• Dina Scarpi,
• Ernesto G. Occhiato and
• Enrique Gómez-Bengoa

Beilstein J. Org. Chem. 2020, 16, 3059–3068, doi:10.3762/bjoc.16.255

• minima. Ph3P was chosen as the ligand in analogy to the previous calculations on compound 1 [16]. Computational discussion In analogy to similar processes [11][21][22][40][41], the reaction is initiated by a two-step [3,3]-acetate rearrangement [42], triggered by the coordination of the cationic gold

All-carbon [3 + 2] cycloaddition in natural product synthesis

• Zhuo Wang and
• Junyang Liu

Beilstein J. Org. Chem. 2020, 16, 3015–3031, doi:10.3762/bjoc.16.251

• % yield, which possesses three contiguous stereocenters with vicinal all-carbon quaternary centers. (Scheme 11A). According to the proposed mechanism, coordination of the triple bond of 142 to the electrophilic platinum complex A followed by intramolecular nucleophilic attack by the methoxy group gives

A novel and robust heterogeneous Cu catalyst using modified lignosulfonate as support for the synthesis of nitrogen-containing heterocycles

• Bingbing Lai,
• Meng Ye,
• Ping Liu,
• Minghao Li,
• Rongxian Bai and
• Yanlong Gu

Beilstein J. Org. Chem. 2020, 16, 2888–2902, doi:10.3762/bjoc.16.238

• to the −SO3 and O−S−O stretching of the −SO3Na (or −SO3H) group [18][19]. Grafting of the FAS moiety changed the peak pattern of –SO3Na in LS-FAS material, and the immobilization of the Cu complex shifted the corresponding peaks to a higher wavenumber position, implying the successful coordination of

Using multiple self-sorting for switching functions in discrete multicomponent systems

• Amit Ghosh and
• Michael Schmittel

Beilstein J. Org. Chem. 2020, 16, 2831–2853, doi:10.3762/bjoc.16.233

• undemanding building blocks. The plethora of self-sorting systems depends on either the geometric fit of their global shapes and/or matching of their local interactions. Various noncovalent interactions, such as H‐bonding [8][9], metal–ligand coordination [10][11][12][13], electrostatic interactions [14], π

• units as the metal-coordination units (Figure 9a). When the ligand 20 was mixed with Fe2+ or Zn2+ ions, the tetrahedral cage complexes [M4(20)12]8+ were formed quantitatively. The flexibility through a methylene linker in 20 allowed the formation of the S4-symmetric cages [Fe4(20)12]8+ or [Zn4(20)12]8

A heterobimetallic tetrahedron from a linear platinum(II)-bis(acetylide) metalloligand

• Matthias Hardy,
• Marianne Engeser and
• Arne Lützen

Beilstein J. Org. Chem. 2020, 16, 2701–2708, doi:10.3762/bjoc.16.220

• these two design concepts – the subcomponent self-assembly strategy and the complex-as-a-ligand approach – ensured a fast and easy synthesis of large heterobimetallic coordination cages of tetrahedral shape with a diameter of more than 3 nm as a mixture of all three possible T-, S4- and C3-symmetric

• platinum(II) ions to be especially suitable to prepare a linear metalloligand due to their highly predictable square-planar coordination environment that can easily be employed to access tetravalent planar or divalent V-shaped cis- or linear trans-configurated complexes [43][44][45]. In this context

Optical detection of di- and triphosphate anions with mixed monolayer-protected gold nanoparticles containing zinc(II)–dipicolylamine complexes

• Lena Reinke,
• Julia Bartl,
• Marcus Koch and
• Stefan Kubik

Beilstein J. Org. Chem. 2020, 16, 2687–2700, doi:10.3762/bjoc.16.219

• involve the binding of an anion to two identical functional groups. A prominent example is the coordination of diphosphate ions to zinc(II)–dipicolylamine complexes, which is most efficient if the anion binds to two metal centers (Figure 1) [22][23][24][25]. This mode of binding is strong even in aqueous

• obtained in a similar fashion by using (R)-lipoic acid in the coupling reaction. The ligand 2 contained a peripheral 2,2'-dipicolylamine residue for zinc(II) coordination. This group was separated from the lipoic acid anchor group by a C12 chain to ensure that it had a sufficient distance from the

Synthesis of 4-substituted azopyridine-functionalized Ni(II)-porphyrins as molecular spin switches

• Jannis Ludwig,
• Tobias Moje,
• Fynn Röhricht and
• Rainer Herges

Beilstein J. Org. Chem. 2020, 16, 2589–2597, doi:10.3762/bjoc.16.210

• azopyridines as covalently attached photoswitchable ligands. The molecules are designed in such a way that the azopyridines coordinate to the Ni ion if the azo unit is in cis configuration. For steric reasons no intramolecular coordination is possible if the azopyridine unit adopts the trans configuration

• . Photoisomerization of the azo unit between cis and trans is achieved upon irradiation with 505 nm (trans→cis) and 435 nm (cis→trans). Concurrently with the isomerization and coordination/decoordination, the spin state of the Ni ion switches between singlet (low-spin) and triplet (high-spin). Previous studies have

• ) nitrogen (“needle”) is placed onto the Ni ion. The coordination number of the Ni2+ ion changes from 4 (square planar) to 5 (square pyramidal) and concomitantly, the spin state changes from low-spin (singlet, diamagnetic) to high-spin (triplet, paramagnetic). Previous studies have shown that all three

Thermodynamic and electrochemical study of tailor-made crown ethers for redox-switchable (pseudo)rotaxanes

• Henrik Hupatz,
• Marius Gaedke,
• Hendrik V. Schröder,
• Julia Beerhues,
• Arto Valkonen,
• Fabian Klautzsch,
• Sebastian Müller,
• Felix Witte,
• Kari Rissanen,
• Biprajit Sarkar and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2020, 16, 2576–2588, doi:10.3762/bjoc.16.209

• strong electrostatic interactions to ammonium ions and act as strong, competitive hydrogen-bond acceptors [57]. The high anodic shifts indicate strong attractive interactions between the wheels and axles, which compete with the coordination of the crown ether moiety. Thus, the secondary ammonium axles

Palladium nanoparticles supported on chitin-based nanomaterials as heterogeneous catalysts for the Heck coupling reaction

• Tony Jin,
• Malickah Hicks,
• Davis Kurdyla,
• Sabahudin Hrapovic,
• Edmond Lam and
• Audrey Moores

Beilstein J. Org. Chem. 2020, 16, 2477–2483, doi:10.3762/bjoc.16.201

• NPs. A one-pot synthesis method was used to both deposit Pd salts and reduce them into NPs onto the support material. First, PdCl2 was mixed for 15 min with either ChNC or ChsNC in an acidic aqueous medium to form a dark yellow mixture. This step facilitated coordination of Pd salts onto the support

• afford much stronger coordination to Pd(II) than OH typically present in CNC, and potentially prevent its full reduction. Through FTIR (Supporting Information File 1, Figure S2) and XRD (Supporting Information File 1, Figure S3) analysis, there is little to no structural changes occurring in either the

Recent developments in enantioselective photocatalysis

• Callum Prentice,
• James Morrisson,
• Andrew D. Smith and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2020, 16, 2363–2441, doi:10.3762/bjoc.16.197

• desired products 267 or 268 in moderate yields and enantioselectivities (3 examples, up to 75:25 er for 267 and 2 examples, up to 68:32 er for 268). Lewis acid catalysis Lewis acids have been known for decades to activate carbonyl compounds through the formation of coordination complexes that increases

• scandium Lewis acid (ET = 1.43 eV), is significantly lower relative to the unbound substrate (ET = 2.34 eV). They propose that Lewis acid coordination permits discrimination between bound and unbound substrate as it allows for selective triplet sensitisation of the bound substrate by the excited state

• -chloro ketone 301 is used with α-aminocarboxylic acids 302 (Scheme 50) [122]. In this reaction, 301 now forms coordination complex 303, which upon excitation is

Hierarchically assembled helicates as reaction platform – from stoichiometric Diels–Alder reactions to enamine catalysis

• David Van Craen,
• Jenny Begall,
• Johannes Großkurth,
• Leonard Himmel,
• Oliver Linnenberg,
• Elisabeth Isaak and
• Markus Albrecht

Beilstein J. Org. Chem. 2020, 16, 2338–2345, doi:10.3762/bjoc.16.195

• “Werner-type” triscatecholate titanium(IV) complex. Two of these monomers dimerized in a consecutive step to obtain a non-covalently linked helicate (Scheme 1). The dimerization took place via the coordination of three lithium cations acting as bridges between two monomeric complex units [13][14][15][16

• processes based on the principle to use self-assembled coordination platforms (or as in the present case mixtures thereof) to control stereoselective C–C bond-forming reactions. Stereoinduction usually relies on spatial proximity of the prochiral carbon atoms and a chiral information of, e.g., a chiral

Synthetic approaches to bowl-shaped π-conjugated sumanene and its congeners

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 2212–2259, doi:10.3762/bjoc.16.186

• /H2O solution, but they received unsuccessful results may be due to its unstable behavior. Pleasingly, they got the fruitful result by converting 120 into phenylboronate ester 121 as can be noted from an inspection of Scheme 29. 2.3 Complexation of sumanene and its derivatives Since coordination is one

• of the vital modes in metal binding and a range of π-conjugated planar systems having ηn-binding to metals have been reported. In contrast, buckybowls have multiple coordination sites for instance the positions available in the polycyclic architecture and also because of the presence of concave or

• convex faces. Therefore, in recent years, the coordination of bowl-shaped molecules with the transition metals is of fundamental interest in the area of π-bowls chemistry since the first details of the metal complex of C60. In this context, Hirao’s group has reported the first example of Fe(η6-sumanene

Azo-dimethylaminopyridine-functionalized Ni(II)-porphyrin as a photoswitchable nucleophilic catalyst

• Jannis Ludwig,
• Julian Helberg,
• Hendrik Zipse and
• Rainer Herges

Beilstein J. Org. Chem. 2020, 16, 2119–2126, doi:10.3762/bjoc.16.179

• + ion. Light of 435 nm (violet) isomerizes the ligand back to the trans configuration, which decoordinates for steric reasons. This so-called record player design has been used previously to switch the spin state of Ni2+ between singlet and triplet. We now use the coordination/decoordination process to

• switch the catalytic activity of the dimethylaminopyridine (DMAP) unit. DMAP is a known catalyst in the nitroaldol (Henry) reaction. Upon coordination to the Ni2+ ion, the basicity of the pyridine lone pair is attenuated and hence the catalytic activity is reduced. Decoordination restores the catalytic

• -epoxypropane to propylene carbonate using an aluminum porphyrin and a photoresponsive ligand. The catalytic activity of the metal porphyrin depended on the axial coordination of an azostilbene and coordination of the latter ligand was controlled by photoisomerization of the stilbene unit [9]. Hecht et al

Efficient [(NHC)Au(NTf₂)]-catalyzed hydrohydrazidation of terminal and internal alkynes

• Maximillian Heidrich and
• Herbert Plenio

Beilstein J. Org. Chem. 2020, 16, 2080–2086, doi:10.3762/bjoc.16.175

• oxygen and nitrogen-containing molecules, which tend to be more difficult for catalytic transformations utilizing other transition metals [32][33][34][35][36]. The [LAu(NTf2)]-catalyzed reaction can be described by a general mechanism (Scheme 1), in which the coordination of LAu+ by the alkyne [37][38

Isolation and structure determination of a tetrameric sulfonyl dilithio methandiide in solution based on crystal structure analysis and ⁶Li/¹³C NMR spectroscopic data

• Jürgen Vollhardt,
• Hans Jörg Lindner and
• Hans-Joachim Gais

Beilstein J. Org. Chem. 2020, 16, 2057–2063, doi:10.3762/bjoc.16.172

• dianionic carbon atom, including its electronic structure and coordination geometry, together with the possibility of a coordination by two lithium atoms. The sulfonyl dilithio methandiides 2, carrying various substituents R1 and R2, have attracted particular attention [1][2][3][4][5][6]. Reactivity studies

• and dynamics in solution [1][2][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43]. The main obstacles at characterizing dilithio methandiides in terms of aggregate size, C–Li connectivity, Li coordination of the dianionic C atoms, and

• coordination chemistry in general, and of the dianionic C atom in particular. During the structural investigation of 2a it was observed that the Li2O-free methandiide is in contrast to (2a)6·Li2O·(THF)6 readily soluble in THF. 6Li and 13C NMR spectroscopy of 2a had led to the detection of an aggregate, a

Synergy between supported ionic liquid-like phases and immobilized palladium N-heterocyclic carbene–phosphine complexes for the Negishi reaction under flow conditions

• Edgar Peris,
• Raúl Porcar,
• María Macia,
• Jesús Alcázar,
• Eduardo García-Verdugo and
• Santiago V. Luis

Beilstein J. Org. Chem. 2020, 16, 1924–1935, doi:10.3762/bjoc.16.159

• cross-coupling; NHC complex; palladium; supported ionic liquid; Introduction N-heterocyclic carbenes (NHCs) are known as efficient coordination ligands for different types of metals. The main feature of NHC complexes is their structural tunability [1]. Thus, their catalytic efficiency can be easily

On the hydrolysis of diethyl 2-(perfluorophenyl)malonate

• Ilya V. Taydakov and
• Mikhail A. Kiskin

Beilstein J. Org. Chem. 2020, 16, 1863–1868, doi:10.3762/bjoc.16.153

• ., pharmacologically active substances [1][2][3][4][5], in asymmetric synthesis and catalysis [6][7][8], as precursors of heterocyclic compounds [9][10][11], as ligands in coordination chemistry [12][13][14][15][16] and for other applications [17][18]. Incorporation of fluorine atoms into an organic molecule is known

• range by fluorination (directly or indirectly) of initial organic molecules. In the ongoing project, we are interested in synthesizing 2-(perfluorophenyl)malonic acid (2, Figure 1) as a new ligand for the preparation of 3d and 4f heterometallic coordination compounds. Results and Discussion To our

When metal-catalyzed C–H functionalization meets visible-light photocatalysis

• Lucas Guillemard and
• Joanna Wencel-Delord

Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147

• metal catalyst X2M into an aromatic C–H bond of a substrate (generally facilitated by the presence of a directing group (DG)), delivers a metal–aryl complex. Coordination and subsequent insertion of an alkene into the M–aryl bond then provides the desired coupling product after β-hydride elimination

• undergoes cyclometalation via a concerted metalation–deprotonation (CMD) process furnishing a cyclometalated intermediate. Thereafter, coordination and subsequent insertion of the alkyne into the Co–C bond delivers a seven-membered cobaltacycle. The desired coupling product is then liberated by reductive

• single electron-transfer process (Figure 36). In the first place, a bidentate chelated species is formed by the coordination of 1-naphthylamine derivatives with copper salt. The subsequent oxidation of this intermediate with potassium persulfate produces a Cu(III) species, furnishing a radical cation on

Pauson–Khand reaction of fluorinated compounds

• Jorge Escorihuela,
• Daniel M. Sedgwick,
• Alberto Llobat,
• Mercedes Medio-Simón,
• Pablo Barrio and
• Santos Fustero

Beilstein J. Org. Chem. 2020, 16, 1662–1682, doi:10.3762/bjoc.16.138

• still valid nowadays [33], although only the first intermediate (I) has been isolated and characterized [34]. However, contributions by Nakamura, Pericàs, and others support the initial proposal both experimentally and theoretically [35][36]. Firstly, two coordination vacancies are freed after the

• extrusion of two carbon monoxide ligands from the starting cobalt species, allowing the alkyne group to bind to the cobalt metal centers. The subsequent coordination of the olefin counterpart requires the extrusion of a third carbon monoxide ligand, leading to pentacarbonyl complex II. This highly

• -oxide (TMANO), and dimethyl sulfoxide (DMSO). Once a new coordination vacancy has been opened on one of the cobalt centers, coordination of the olefin sets the stage for the subsequent C–C bond forming steps. The olefin is inserted into the less hindered Co–C bond, determining both the regio- and