Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

• first part will be devoted to chemically responsive tweezers, including stimuli such as pH, metal coordination, and anion binding. Then, redox-active and photochemical tweezers will be presented. Keywords: coordination; molecular recognition; molecular switches; photoswitch; redox; supramolecular

• , the terpyridine adopts an open "W"-shaped conformation due to the s-trans-conformation between two pyridines forced by the repulsion of the nitrogen lone pairs. Upon metal coordination the pyridine units rotate to allow for a tridentate binding to the metal cation, thus inducing a molecular motion to

• [36] as it is isomorphic to the terpyridine and presents similar metal coordination properties [36][37][38]. Molecular tweezers 10 bearing 1,4,5,8-naphthalenediimide (NDI) luminescent arms have thus been developed. The system exhibits similar switching behavior as the terpyridine tweezers. In terms of

Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• and the quinones react with unoxidized catechols to form o-semiquinone radicals afterwards [12]. The semiquinone radicals can help DOPA adhere onto organic surfaces. At a basic pH, the system is cured and mechanically stabilized through the formation of DOPA-metal coordination bonds. The cohesion of

Pyridine C(sp²)–H bond functionalization under transition-metal and rare earth metal catalysis

• Haritha Sindhe,
• Malladi Mounika Reddy,
• Karthikeyan Rajkumar,
• Akshay Kamble,
• Amardeep Singh,
• Anand Kumar and
• Satyasheel Sharma

Beilstein J. Org. Chem. 2023, 19, 820–863, doi:10.3762/bjoc.19.62

• through the trans-effect (Scheme 18). The trans-effect is the switching of the metal coordination between the π-ring system and the hetero-(nitrogen) atom of pyridine [84][85]. In comparison to coordination with nitrogen, which is strong in nature, the coordination with the ring is weaker and cleavable

A new oxidatively stable ligand for the chiral functionalization of amino acids in Ni(II)–Schiff base complexes

• Alena V. Dmitrieva,
• Oleg A. Levitskiy,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2023, 19, 566–574, doi:10.3762/bjoc.19.41

• base chiral template is a fairly versatile “tool” that can be adapted to a specific task. A relatively new approach to functionalization of amino acids is a combination of a stereoselective synthesis in a metal-coordination environment with electrochemical activation [31]. It increases the reactivity

Reductive opening of a cyclopropane ring in the Ni(II) coordination environment: a route to functionalized dehydroalanine and cysteine derivatives

• Oleg A. Levitskiy,
• Olga I. Aglamazova,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2022, 18, 1166–1176, doi:10.3762/bjoc.18.121

• cysteine derivatives in practical yields and with high stereoselectivity at the removed β-stereocenter. The developed one-pot multistep procedure highlights new perspectives provided by combination of electrochemically broaden DA-cyclopropane concept and chirality induction within a metal coordination

Biological properties and conformational studies of amphiphilic Pd(II) and Ni(II) complexes bearing functionalized aroylaminocarbo-N-thioylpyrrolinate units

• Samet Poyraz,
• Samet Belveren,
• Sabriye Aydınoğlu,
• Mahmut Ulger,
• Abel de Cózar,
• Maria de Gracia Retamosa,
• Jose M. Sansano and
• H. Ali Döndaş

Beilstein J. Org. Chem. 2021, 17, 2812–2821, doi:10.3762/bjoc.17.192

• nickel or palladium atoms. As far as the L1-Ni complex was concerned, this fluxional equilibrium disappeared due to metal coordination. In this case, complexes involving conformer B were highly energetic due to steric repulsion between the CO2Me substituents of the pyrrolidine ring. Thus, only one set of

Structural effects of meso-halogenation on porphyrins

• Keith J. Flanagan,
• Maximilian Paradiz Dominguez,
• Zoi Melissari,
• Hans-Georg Eckhardt,
• René M. Williams,
• Dáire Gibbons,
• Caroline Prior,
• Gemma M. Locke,
• Alina Meindl,
• Aoife A. Ryan and
• Mathias O. Senge

Beilstein J. Org. Chem. 2021, 17, 1149–1170, doi:10.3762/bjoc.17.88

• ‘guests’ within the crystal lattice, through hydrogen-bonding and van der Waals forces. Thereafter, research over the crystal engineering of porphyrins has focused on the noncovalent interactions, such as hydrogen bonds and halogen bonds, or metal coordination interactions [2][3][4][5][6][7][8][9][10][11

Synthesis of dibenzosuberenone-based novel polycyclic π-conjugated dihydropyridazines, pyridazines and pyrroles

• Ramazan Koçak and
• Arif Daştan

Beilstein J. Org. Chem. 2021, 17, 719–729, doi:10.3762/bjoc.17.61

• biochemical studies on these compounds, which have the potential to be used in chemosensors, light harvesting, organic optoelectronics, metal coordination complexes and other photophysical applications and in biological systems. Structures of dibenzosuberenone 1 and pyridazine and pyrrole derivatives

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

• 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

Photocatalyzed syntheses of phenanthrenes and their aza-analogues. A review

• Alessandra Del Tito,
• Havall Othman Abdulla,
• Davide Ravelli,
• Stefano Protti and
• Maurizio Fagnoni

Beilstein J. Org. Chem. 2020, 16, 1476–1488, doi:10.3762/bjoc.16.123

• proximity to each other, prone to be engaged in a bidentate-type metal-coordination complex [75]. 2.2 Synthesis of phenanthridines via photocatalyzed C–N bond formation As mentioned in the introduction, the examples gathered here involve the intermediacy of N-centered radicals. As a representative case, the

In silico rationalisation of selectivity and reactivity in Pd-catalysed C–H activation reactions

• Liwei Cao,
• Mikhail Kabeshov,
• Steven V. Ley and
• Alexei A. Lapkin

Beilstein J. Org. Chem. 2020, 16, 1465–1475, doi:10.3762/bjoc.16.122

• transition metal coordination sphere; the energy of a new M–C bond formed and the thermodynamic stability of organometallic product. With new developments in computational chemistry, mechanistic studies using density functional theory (DFT) provide valuable insights into the reactivity of organometallic

Architecture and synthesis of P,N-heterocyclic phosphine ligands

• Wisdom A. Munzeiwa,
• Bernard Omondi and
• Vincent O. Nyamori

Beilstein J. Org. Chem. 2020, 16, 362–383, doi:10.3762/bjoc.16.35

• ] among other fields (Table 1). There is a number of review articles in the literature [9][10][11] which explore deeper into the applications of P,N-heterocyclic phosphine ligands. Besides, the inclusion of other heteroatoms in the phosphine ligand skeleton opens up many possibilities for metal

• coordination [12]. Thus, their use in catalysis is the basis of this review article with the main focus on the synthesis of N-heterocyclic phosphines. The presence of soft donor atoms such as phosphorus results in the formation of hemilabile ligands. These are multidentate ligands having hard P-donor and soft

A chiral self-sorting photoresponsive coordination cage based on overcrowded alkenes

• Constantin Stuckhardt,
• Diederik Roke,
• Wojciech Danowski,
• Edwin Otten,
• Sander J. Wezenberg and
• Ben L. Feringa

Beilstein J. Org. Chem. 2019, 15, 2767–2773, doi:10.3762/bjoc.15.268

• Pd2(stable E-1)4, respectively, as evidenced by 1H NMR, DOSY and HRMS. The 1H NMR signals of the pyridine moieties of the ligands (Ha–d) in the assembled cages are shifted downfield compared to those of the free ligands, as expected due to metal coordination (Figure 2) [28]. As the ligand exchange in

Self-assembled coordination thioether silver(I) macrocyclic complexes for homogeneous catalysis

• Zhen Cao,
• Aline Lacoudre,
• Cybille Rossy and
• Brigitte Bibal

Beilstein J. Org. Chem. 2019, 15, 2465–2472, doi:10.3762/bjoc.15.239

• candidates for directional metal coordination. Herein, a new syn-atropisomer of 9,10-DPA ortho-substituted by two thioethers is exploited as a ligand for silver(I) salts. The impact of this bis-thioether ligand on silver(I) homogeneous catalysis is evaluated in two tandem addition/cycloisomerization

Photochromic diarylethene ligands featuring 2-(imidazol-2-yl)pyridine coordination site and their iron(II) complexes

• Andrey G. Lvov,
• Max Mörtel,
• Anton V. Yadykov,
• Frank W. Heinemann,
• Valerii Z. Shirinian and
• Marat M. Khusniyarov

Beilstein J. Org. Chem. 2019, 15, 2428–2437, doi:10.3762/bjoc.15.235

• ligands feature non-aromatic ethene bridges (cyclopentene, cyclopentenone, and cyclohexenone), as well as closely spaced photoactive and metal coordination sites aiming a strong impact of photocyclization on the electronic structure of the coordinated metal ion. The ligands with cyclopentenone and

• ligand systems, including 1,10-phenanthroline, 2-(azol-2-yl)pyridine, and related frameworks to yield photochromic ligands. The latter can be divided into two groups based on the position of the metal coordination site relative to the photoactive hexatriene unit of a diarylethene. Some diarylethene-based

• context, it is important to specify some design principles for such ligands. Firstly, novel ligands should feature a non-aromatic ethene bridge to increase the life-time of a photoinduced closed-ring isomer [28]. Secondly, photoactive hexatriene and metal coordination sites should be close to each other

Perspective isomorphs – a new classification of molecular structures based on artistic and chemical concepts

• Jannis Neumann,
• Ansgar Schnurr and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2019, 15, 2319–2326, doi:10.3762/bjoc.15.224

• Contextualization The understanding of space in chemistry is highly linked to the three-dimensional extensions of molecules and their directionality in chemical bonds, reactions, and processes. In this context, interactions, such as hydrogen-bonds [3], metal-coordination [4] or quadrupole interactions [5][6

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

• substrate containing benzylic C–H bonds with acidic sodium dichromate or basic potassium permanganate [3][4][5]. More recent examples have used metal coordination complexes as catalysts for oxidation [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Additionally, transition metal-based complexes are

Olefin metathesis in multiblock copolymer synthesis

• Maria L. Gringolts,
• Yulia I. Denisova,
• Eugene Sh. Finkelshtein and
• Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2019, 15, 218–235, doi:10.3762/bjoc.15.21

• (Scheme 7). In more detail, the synthesis included ROMP of NB octyl ester or NB by means of metal coordination using the obtained telechelic polymers methyl triglycol ester in the presence of the bimetallic ruthenium catalyst followed by the addition of an excess of either a Pd-containing chain terminator

Revisiting ring-degenerate rearrangements of 1-substituted-4-imino-1,2,3-triazoles

• James T. Fletcher,
• Matthew D. Hanson,
• Joseph A. Christensen and
• Eric M. Villa

Beilstein J. Org. Chem. 2018, 14, 2098–2105, doi:10.3762/bjoc.14.184

• -temperature conditions, such as commonly used in preparing metal coordination compounds. While the pairing of electron-rich formyltriazoles with electron-poor amines slows the rate of rearrangement, it does not preclude the ability of such analogs to rearrange significantly into scrambled analogs. Among the

Metal-mediated base pairs in parallel-stranded DNA

• Jens Müller

Beilstein J. Org. Chem. 2017, 13, 2671–2681, doi:10.3762/bjoc.13.265

• be seen, base pairs including at least one 2PyrPC moiety display the largest stabilization, which points towards an involvement of the endocyclic pyridyl nitrogen atom in metal coordination particularly for the parallel-stranded duplexes. For the shorter 12-mer duplexes, the stabilizing effect of

Exploring mechanochemistry to turn organic bio-relevant molecules into metal-organic frameworks: a short review

• Vânia André,
• Sílvia Quaresma,
• João Luís Ferreira da Silva and
• M. Teresa Duarte

Beilstein J. Org. Chem. 2017, 13, 2416–2427, doi:10.3762/bjoc.13.239

• . Gabapentin was also used by Quaresma et al. [124] in the synthesis by manual grinding of seventeen new metal coordination networks with Y(III), Mn(II) and several lanthanide chlorides (LnCl3), Ln = La3+, Ce3+, Nd3+, and Er3+. Ten out of these compounds were structurally characterized and represent the first

A new class of organogelators based on triphenylmethyl derivatives of primary alcohols: hydrophobic interactions alone can mediate gelation

• Wangkhem P. Singh and
• Rajkumar S. Singh

Beilstein J. Org. Chem. 2017, 13, 138–149, doi:10.3762/bjoc.13.17

• -stacking, donor–acceptor interaction, electrostatic, metal coordination, hydrophobic forces or van der Waals’ interactions [4][5][6]. We know a great deal about the aggregation behaviour of gelator molecules from many studies conducted during the past several years. However, rational design and accurate

• ][21][22]. As mentioned above, developing a new gelator is still largely a trial and error method. The most widely used design strategy involves the inclusion of structural components favouring intermolecular non-covalent interactions (like H-bonding, π-stacking, donor–acceptor interaction, metal

• coordination, ionic, hydrophobic forces, etc.) into the gelator molecular structure and studying their gelation behaviour. H-bonding interaction (present in amide, urea, carbamate linkages, etc) alone or in combination with other interactions is the most extensively used strategy in the design of gelators [23

Stereo- and regioselectivity of the hetero-Diels–Alder reaction of nitroso derivatives with conjugated dienes

• Lucie Brulíková,
• Aidan Harrison,
• Marvin J. Miller and
• Jan Hlaváč

Beilstein J. Org. Chem. 2016, 12, 1949–1980, doi:10.3762/bjoc.12.184

• –Alder products 91, 93, 95 and 97. Regiocontrol of the reaction between 3-dienyl-2-azetidinones and nitrosobenzene due to change in a single stereocenter. Regiocontrol of the reaction between diene 111 and 2-methyl-6-nitrosopyridine (112) due to metal coordination. Asymmetric hetero-Diels–Alder reactions

From steroids to aqueous supramolecular chemistry: an autobiographical career review

• Bruce C. Gibb

Beilstein J. Org. Chem. 2016, 12, 684–701, doi:10.3762/bjoc.12.69

• entirely different approach to the assembly of container molecules; up until that point strategies such as hydrogen bonding or metal coordination were the focus of attention. Our first investigations with octa-acid looked at assembly around steroids [31]. There was obviously a personal reason for this, but

Creating molecular macrocycles for anion recognition

• Amar H. Flood

Beilstein J. Org. Chem. 2016, 12, 611–627, doi:10.3762/bjoc.12.60

• purpose of transition-metal coordination, an area in which I received my Ph.D. training with Keith Gordon. I asked my postdoctoral co-worker at the time, Yongjun Li, to assist with testing the idea. We prepared a series of analogs to the common terpyridine ligand (Figure 4a,b). Once made, they indeed