A systematic review on silica-, carbon-, and magnetic materials-supported copper species as efficient heterogeneous nanocatalysts in “click” reactions

• Pezhman Shiri and
• Jasem Aboonajmi

Beilstein J. Org. Chem. 2020, 16, 551–586, doi:10.3762/bjoc.16.52

• , compound 36 could be recycled and used in seven subsequent cycles. A further example of a silica-supported CuAAC catalyst was reported by Moghadam et al. (Scheme 7) [29]. In this study, the bis(benzothiazole)-substituted pyridine ligand BTP (41) was synthesized through the condensation of 2-aminothiophenol

Synthesis of 3-alkenylindoles through regioselective C–H alkenylation of indoles by a ruthenium nanocatalyst

• Abhijit Paul,
• Debnath Chatterjee,
• Srirupa Banerjee and
• Somnath Yadav

Beilstein J. Org. Chem. 2020, 16, 140–148, doi:10.3762/bjoc.16.16

• of indoles using Pd(OAc)2 and Pd(II)/polyoxometallate, respectively, as a catalyst and molecular oxygen as the oxidant [26][27]. Verma and co-workers used the reaction between indoles and alkenes in the presence of a Pd(OAc)2 catalyst, a Cu(OAc)2 oxidant, and a 2-(1-benzotriazolyl)pyridine ligand [28

Bioinspired cobalt cubanes with tunable redox potentials for photocatalytic water oxidation and CO₂ reduction

• Zhishan Luo,
• Yidong Hou,
• Jinshui Zhang,
• Sibo Wang and
• Xinchen Wang

Beilstein J. Org. Chem. 2018, 14, 2331–2339, doi:10.3762/bjoc.14.208

• pyridine ligand provides further insight into the factors that affect the redox potential and tailor the catalytic performance. Furthermore, by exploring the structure–function relationship at the molecular level offers a useful guidance for the design and construction of high-performance earth-abundant

• -OMe (3.3 μmol·h−1), which is consistent with the effect of the substituent groups on the pyridine ligand of 1-R on the electrochemical oxygen evolution. These results indicated that water oxidation is favored by the presence of electron-withdrawing ligands. Additionally, the activity of water

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

• complex to promote the enantioselective addition of methanol to N-Boc-isatin imines 3 [79]. As shown in Scheme 20, the use of a chiral nickel catalyst in situ generated from NiCl2 and the chiral bis(imidazolidine)pyridine ligand 56 promoted this reaction in toluene at room temperature in the presence of a

Cross-dehydrogenative coupling for the intermolecular C–O bond formation

• Igor B. Krylov,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2015, 11, 92–146, doi:10.3762/bjoc.11.13

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

• of the racemic material was transformed into the corresponding racemic ditriflate (rac)-2 which was reacted with a 4-pyridylboronic acid ester in a Suzuki cross-coupling to afford the desired racemic bis(pyridine) ligand (rac)-3. (Please note that (rac)-3 has been prepared before, however, on a

• . (R)-2 was then subjected to a two-fold Suzuki reaction to obtain the enantiomerically pure bis(pyridine) ligand (R)-3. (Please note, that the conditions used to elaborate the enantiomerically pure 9,9’-spirobifluorene derivatives were demonstrated not to affect the optical purity of these compounds

• 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

Synthesis, characterization and luminescence studies of gold(I)–NHC amide complexes

• Adrián Gómez-Suárez,
• David J. Nelson,
• David G. Thompson,
• David B. Cordes,
• Duncan Graham,
• Alexandra M. Z. Slawin and
• Steven P. Nolan

Beilstein J. Org. Chem. 2013, 9, 2216–2223, doi:10.3762/bjoc.9.260

• of complexes 2, 3, 7, 8, 10, 11 and 12. Hydrogen atoms are omitted for clarity. Selected examples of gold–NHC amide complexes under UV light (λ = 366 nm). Excitation (blue) and emission (pink) data for complex 3, bearing a 2-pyridine ligand (see inset). (a) LUMO, (b) HOMO and (c) HOMO-1 of complex 3

The catalytic performance of Ru–NHC alkylidene complexes: PCy₃ versus pyridine as the dissociating ligand

• Stefan Krehl,
• Diana Geißler,
• Sylvia Hauke,
• Oliver Kunz,
• Lucia Staude and
• Bernd Schmidt

Beilstein J. Org. Chem. 2010, 6, 1188–1198, doi:10.3762/bjoc.6.136

• benzylidene complexes bearing a tricyclohexylphosphine or a pyridine ligand in ring closing metathesis (RCM), cross metathesis, and ring closing enyne metathesis (RCEYM) reactions is compared. While the PCy3 complexes perform significantly better in RCM and RCEYM reactions than the pyridine complex, all

• catalysts show similar activity in cross metathesis reactions. Keywords: homogeneous catalysis; N-heterocyclic carbenes; olefin metathesis; pyridine ligand; Ruthenium carbene complexes; Introduction Over the past two decades, the olefin metathesis reaction became one of the most important C–C-bond forming

• surprising – for acetic acid [49]. Therefore, we used ethyl acetate and acetic acid for our test reaction. While ethyl acetate gave a conversion of 75%, which is better than most of the classical solvents, nearly quantitative conversion to the RCM product was observed in acetic acid. Presumably, the pyridine