Cyclodextrin-based Schiff base pro-fragrances: Synthesis and release studies

• Attila Palágyi,
• Jindřich Jindřich,
• Juraj Dian and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2022, 18, 1346–1354, doi:10.3762/bjoc.18.140

• – cinnamaldehyde, cyclamen aldehyde, lilial, benzaldehyde, anisaldehyde, vanillin, hexanal, heptanal, citral, and 5-methylfurfural. Subsequently, the rate of release of the volatile compound from selected pro-fragrances, as a function of the environment (solvent, pH), was studied by 1H NMR spectroscopy (for

• benzaldehyde) and static headspace-gas chromatography (for benzaldehyde, heptanal, and 5-methylfurfural). The aldehyde release rate from the imine was shown to depend substantially on the pH from the solution and the air humidity from the solid state. Keywords: aldehyde; controlled release; cyclodextrin

• industry, the covalent bond that links the fragrance to its substrate must be cleaved under environmental conditions found in everyday life, and the substrate should be non-volatile and non-toxic [17]. Typical triggers that may be used for mild chemical reactions are temperature, enzymatic or pH-dependent

Computational model predicts protein binding sites of a luminescent ligand equipped with guanidiniocarbonyl-pyrrole groups

• Neda Rafieiolhosseini,
• Matthias Killa,
• Thorben Neumann,
• Niklas Tötsch,
• Jean-Noël Grad,
• Alexander Höing,
• Thies Dirksmeyer,
• Jochen Niemeyer,
• Christian Ottmann,
• Shirley K. Knauer,
• Michael Giese,
• Jens Voskuhl and
• Daniel Hoffmann

Beilstein J. Org. Chem. 2022, 18, 1322–1331, doi:10.3762/bjoc.18.137

• ). Additionally, fluorescence- and UV-titration experiments suggested a dissociation constant in the low micromolar range (5.0 ± 0.9 µM/7.5 ± 1.1 µM, respectively) in buffered aqueous solution (25 mM HEPES, 150 mM NaCl, 10 mM MgCl2, 0.5 mM TCEP, pH 6.5) (Supporting Information File 1, Figures S26 and S28

• , [20]) was refined with MODELLER [31] as described in reference [26]. Charges, van der Waals radii and missing hydrogen atoms were added by PDB2PQR v2.0.0 [27][28] at pH 6.5 with the Amber force field option (values are provided as a table in Supporting Information File 2 and in Supporting Information

Make or break: the thermodynamic equilibrium of polyphosphate kinase-catalysed reactions

• Michael Keppler,
• Sandra Moser,
• Henning J. Jessen,
• Christoph Held and
• Jennifer N. Andexer

Beilstein J. Org. Chem. 2022, 18, 1278–1288, doi:10.3762/bjoc.18.134

• [33][34]. Under physiological conditions as well as in an in vitro system the actual ΔG may be different by coordination of cations and the ionic strength, temperature and pH of the reaction solution [29][35][36]. Compared to other ATP synthesis reactions very little is known about the thermodynamics

• between different PPKs [10][15]. First experiments were conducted with the “model PPKs” EcPPK1 and SmPPK2. At 37 °C and pH 8, each enzyme was incubated with either ADP or ATP and polyP as co-substrate; the resulting nucleotide distributions were analysed by HPLC as a function of time (Figure 4). In all

• started with ADP catalysed by a) SmPPK2 and b) EcPPK1. Time courses of reactions started with ATP catalysed by c) SmPPK2 and d) EcPPK1. The nucleotide concentration was 2 mM, the reaction was carried out at pH 8.0 and 37 °C. Grey = AMP, blue = ADP, orange = ATP; the nucleotide composition is given in mol

Enantioselective total synthesis of putative dihydrorosefuran, a monoterpene with an unique 2,5-dihydrofuran structure

• Irene Torres-García,
• Josefa L. López-Martínez,
• Rocío López-Domene,
• Manuel Muñoz-Dorado,
• Ignacio Rodríguez-García and
• Miriam Álvarez-Corral

Beilstein J. Org. Chem. 2022, 18, 1264–1269, doi:10.3762/bjoc.18.132

• is performed with stoichiometric amounts of CpTiCl3 or if catalytic amounts are used [12]. However, using the particular substrates in this approach, the allenic compound 3 was exclusively formed, in a satisfactory 81% yield [14]. It is also important to control the pH during the reaction workup, as

• some contamination of the product with lactone 5 can arise at low pH values, which goes in detriment of the yield. The 2,5-dihydrofuran ring in target compound 1 was obtained through a Ag(I)-mediated intramolecular addition of the hydroxy to the allene group, a process that transformed allene 3 into

• compound 2. The isopropenyl residue of the target compound 1 was assembled through a two-step sequence. The first one was the addition of an excess of methylmagnesium bromide to the ester 2, that completed the carbon skeleton. The second step was the pH-controlled regioselective dehydration of the tertiary

Lewis acid-catalyzed Pudovik reaction–phospha-Brook rearrangement sequence to access phosphoric esters

• Jin Yang,
• Dang-Wei Qian and
• Shang-Dong Yang

Beilstein J. Org. Chem. 2022, 18, 1188–1194, doi:10.3762/bjoc.18.123

• . However, no clear trend regarding electronic effects could be observed since α-pyridinealdehydes bearing either an electron-donating group (e.g., Me, MeO, Ph) or electron-withdrawing group (e.g., F, Cl, Br, CF3, CO2Me) in position 5 were all well tolerated, and the desired products were generally obtained

A Streptomyces P450 enzyme dimerizes isoflavones from plants

• Run-Zhou Liu,
• Shanchong Chen and
• Lihan Zhang

Beilstein J. Org. Chem. 2022, 18, 1107–1115, doi:10.3762/bjoc.18.113

• General Microbiological Culture Collection Center (CGMCC). Seed culture of this strain was done in ISP-2 medium (yeast extract 0.4 g, malt extract 1 g, glucose 0.4 g, distilled water up to 100 mL, pH 7.2) for 2 days. Isoflavone dimer production was performed on MS agar medium (mannitol 20 g, soy flour 20

• 16 °C and induced with 0.1 mM isopropyl β-ᴅ-1-thiogalactopyranoside (IPTG) for 16 h. Cells were harvested by centrifugation (10 min, 8,000 rpm, 4 °C). For protein purification, cell pellets were resuspended in lysis buffer (50 mM NaH2PO4, 400 mM NaCl, 1 mM TCEP, pH 7.5) and lysed by sonication. After

• removing cell debris by centrifugation, the lysate supernatant was purified by Ni-NTA resin with washing buffer (50 mM NaH2PO4, 150 mM NaCl, 100 mM imidazole, pH 7.5) and elution buffer (50 mM NaH2PO4, 150 mM NaCl, 300 mM imidazole, pH 7.5) and then dialyzed into the storage buffer (50 mM NaH2PO4, 150 mM

Isolation and biosynthesis of daturamycins from Streptomyces sp. KIB-H1544

• Yin Chen,
• Jinqiu Ren,
• Ruimin Yang,
• Jie Li,
• Sheng-Xiong Huang and
• Yijun Yan

Beilstein J. Org. Chem. 2022, 18, 1009–1016, doi:10.3762/bjoc.18.101

• , 20 mM imidazole, pH 8.0). After ultrasonic cell crushing, the cells were centrifuged at 24,000 rpm for 60 min to remove cell fragments. The supernatant was filtered through 0.22 μm of the filter membrane and then loaded into the nickel column of the rebalanced lysate (HisTraqTM FF, GE Healthcare

• ). The eluent was removed with buffer B (50 mM Tris-HCl, 300 mM NaCl, 250 mM imidazole, pH 8.0) at a flow rate of 2 mL/min, starting from the fourth tube of the collection tube and ending at the sixth tube. The outgoing protein was collected and poured into a precooled filter column (Ultracel series 10

• KDa; GE Healthcare). Then, the collected DatA (or EchA) protein was concentrated and buffer-exchanged into storage buffer (50 mM NaH2PO4, 100 mM NaCl, pH 8.0, containing 10% glycerin). The proteins were tested by SDS-PAGE, frozen using liquid nitrogen, and kept at −80 °C. In vitro reactions DatA

On Reuben G. Jones synthesis of 2-hydroxypyrazines

• Pierre Legrand and
• Yves L. Janin

Beilstein J. Org. Chem. 2022, 18, 935–943, doi:10.3762/bjoc.18.93

• was made acidic with 37% hydrochloric acid (3.3 mL, 39.31 mmol), diluted in water (150 mL), and stirred for 15 minutes. A saturated solution of sodium hydrogencarbonate was then slowly added to bring the pH to 6, this was extracted with ethyl acetate (3 × 50 mL) and the organic layer was washed with

• sodium hydrogencarbonate was then slowly added to bring the pH to 6, this was extracted with ethyl acetate (3 × 50 mL) and the organic layer was washed with brine (30 mL), dried over magnesium sulfate, and concentrated to dryness. The residue was purified by a chromatography over silica gel (cyclohexane

Synthetic strategies for the preparation of γ-phostams: 1,2-azaphospholidine 2-oxides and 1,2-azaphospholine 2-oxides

• Jiaxi Xu

Beilstein J. Org. Chem. 2022, 18, 889–915, doi:10.3762/bjoc.18.90

• -azaphosphole 2-oxide (95a) in the lowest yield. The (E)-prop-1-enylphosphonodiamide 96 also underwent the RCM well. However, N,N’-dicinnamyl-vinylphosphonodiamides 94b,c (R’ = H, Me, R = Ph) always generated the corresponding N,N’-dicinnamyl-styrylphosphonodiamides 98 in 12–17% yields as byproducts via the RCM

Synthesis and HDAC inhibitory activity of pyrimidine-based hydroxamic acids

• Virginija Jakubkiene,
• Gabrielius Ernis Valiulis,
• Markus Schweipert,
• Asta Zubriene,
• Daumantas Matulis,
• Franz-Josef Meyer-Almes and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 837–844, doi:10.3762/bjoc.18.84

• was stirred at room temperature for 12 h, then water (15 mL) was added to the mixture, and stirring was continued for 5 min. The reaction mixture was acidified with conc. HCl to pH 2 and extracted with DCM. The extract was washed with brine, dried over Na2SO4, and evaporated under reduced pressure

• ) at 0–5 °C a solution of KOH (0.392 g, 7 mmol) in H2O (1 mL) was added dropwise under stirring. The reaction mixture was stirred at this temperature for 1–4 h (in the case of ester 7 it was stirred at room temperature for 96 h), then acidified with conc. HCl to pH 5–6. The resultant precipitate was

• filtered. To the filtrate the corresponding ester 20–24 (1 mmol) was added. The reaction mixture was stirred at 0–5 °C for 1 h, then the solvent was removed under reduced pressure, the residue was dissolved in water, cooled to 0–5 °C and acidified with conc. HCl to pH 5–6. The resultant precipitate was

Post-synthesis from Lewis acid–base interaction: an alternative way to generate light and harvest triplet excitons

• Hengjia Liu and
• Guohua Xie

Beilstein J. Org. Chem. 2022, 18, 825–836, doi:10.3762/bjoc.18.83

• ), DPPPy-Ph-3F (17), and DPPPy-Ph-F (18, Figure 8), and determined the 11B NMR spectra (Figure 9c) [44]. When coordinated with nitrogen atoms, the resonance peak shifted slightly from ca. −10 to 0 ppm, which suggested the interaction between boron and nitrogen atoms. Wang’s group studied the interaction of

• )3 at different temperatures from 300 to 230 K. (c) 11B NMR spectra of B(C6F5)3, DPPPy-Py-F (compound 16)/B(C6F5)3, DPPPy-Ph-3F (compound 17)/B(C6F5)3, and DPPPy-Ph-F (compound 18)/B(C6F5)3 in CD2Cl2, respectively. Figure 9a and 9b were reprinted with permission from [43], Copyright 2011 American

Synthesis of α-(perfluoroalkylsulfonyl)propiophenones: a new set of reagents for the light-mediated perfluoroalkylation of aromatics

• Durbis J. Castillo-Pazos,
• Juan D. Lasso and
• Chao-Jun Li

Beilstein J. Org. Chem. 2022, 18, 788–795, doi:10.3762/bjoc.18.79

• synthetic chemistry, we report the synthesis of a series of bench-stable α-(perfluoroalkylsulfonyl)propiophenones. Their application as photocleavable reagents was tested with electron-rich aromatics under metal-free, redox- and pH-neutral conditions to enable late-stage perfluorooctylation

• halogenation reactions or oxidation. For these reasons, it would be ideal to develop an efficient methodology that allows for the generation of perfluoroalkyl radicals in a mild, redox- and pH-neutral manner, without the assistance of external photocatalysts, heavy metal catalysts, or further additives. Thus

• reactivity of these molecules allows this set of reagents to be both redox- and pH-neutral, while also being highly diversifiable. Additionally, all byproducts generated either during its synthesis or use in following reactions have the potential to be recycled, if so desired. Based on the fact that both

Synthesis of bis-spirocyclic derivatives of 3-azabicyclo[3.1.0]hexane via cyclopropene cycloadditions to the stable azomethine ylide derived from Ruhemann's purple

• Alexander S. Filatov,
• Olesya V. Khoroshilova,
• Anna G. Larina,
• Vitali M. Boitsov and
• Alexander V. Stepakov

Beilstein J. Org. Chem. 2022, 18, 769–780, doi:10.3762/bjoc.18.77

• asymmetric 1,3-dipolar cycloaddition of azomethine ylides and cyclopropenes catalyzed by a chiral Cu-(CH3CN)4BF4/Ph-Phosferrox complex for the construction of 3-azabicyclo[3.1.0]hexane derivatives [25]. Another concise enantioselective approach towards 3-azabicyclo[3.1.0]hexanes is based on a Cp*Ir-catalyzed

Synthesis of odorants in flow and their applications in perfumery

• Merlin Kleoff,
• Paul Kiler and
• Philipp Heretsch

Beilstein J. Org. Chem. 2022, 18, 754–768, doi:10.3762/bjoc.18.76

• %. Thus, Brenna and co-workers developed a cis-selective synthesis of 54 via a biocatalytic process in flow (Scheme 12) [45]. In the first step, a mixture of cyclohexanone 51, NADH, and isopropanol in an aqueous phosphate buffer (pH ≈ 7) is pumped through a continuously stirred membrane reactor at 30 °C

Identification of the new prenyltransferase Ubi-297 from marine bacteria and elucidation of its substrate specificity

• Jamshid Amiri Moghaddam,
• Huijuan Guo,
• Karsten Willing,
• Thomas Wichard and
• Christine Beemelmanns

Beilstein J. Org. Chem. 2022, 18, 722–731, doi:10.3762/bjoc.18.72

• membrane-like environment. Along these lines, no product formation was detectable when UbiA-297 was denaturated by heating prior to the assay (control), nor when a MenA-1335 (Maribacter sp. MS6) homolog was tested. Furthermore, different pH values and extended incubation times were investigated, however

• added to a final concentration of 0.1 mM. Cells were cultivated overnight at 16 °C before harvesting. Cultures were centrifuged, the cell pellet resuspended in Tris-HCl buffer (50 mM, pH 7.8) supplemented with dithiothreitol (DTT, 10 mM), and sonicated on ice (12 min, 100% C, 40% A, 2 seconds on and 3

• obtained protein pellet was resuspended in the same buffer as used for the bioassays. Protein concentration was measured according to Bradford [38]. Enzyme assays: All the enzyme assays were performed using a standard reaction mixture (100 µL) by adding 50 µL Tris-HCl (50 mM, pH 7.8) containing MgCl2, FPP

Shift of the reaction equilibrium at high pressure in the continuous synthesis of neuraminic acid

• Jannis A. Reich,
• Miriam Aßmann,
• Kristin Hölting,
• Paul Bubenheim,
• Jürgen Kuballa and
• Andreas Liese

Beilstein J. Org. Chem. 2022, 18, 567–579, doi:10.3762/bjoc.18.59

• parameters are listed in Table 5. Since Neu5Ac is acidic, 200 mM buffer solution with the addition of K2HPO4 was used to neutralize the solution to pH 7.2. Using the Haldane relation, the calculated equilibrium constants were 27 L/mol and 48 L/mol at 2 MPa and 115 MPa, respectively. Circulation reactor If

• (ECR8309F). For all immobilizations, a 20 mM sodium phosphate buffer with a pH of 7.4 was used as immobilization buffer. All filtration steps were executed using a membrane pump (Membrane pump ME 2C NT, Vacuubrandt GMBH & Co. KG, Wertheim, Germany) with bottle topper filter (Nalgene™, Thermo Fisher

• washed with immobilization buffer. For immobilization, the buffer of purified enzymes (150 mM imidazol, 300 mM NaCl, 50 mM sodium phosphate buffer pH 7.4) was exchanged to the immobilization buffer using ultracentrifuge units with 10 kDa Cut-off (Sartorius Vivaspin™, Göttingen, Germany). The unbuffered

Synthesis of a new water-soluble hexacarboxylated tribenzotriquinacene derivative and its competitive host–guest interaction for drug delivery

• Man-Ping Li,
• Nan Yang and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2022, 18, 539–548, doi:10.3762/bjoc.18.56

• -containing amphiphile (trans-AZO) to produce the TBTQ-C6-trans-AZO supra-amphiphile by host–guest interactions in water. The supra-amphiphile was further self-assembled into photo and pH dual-responsive supramolecular vesicles that have a potential to serve as drug nanocarriers to enable controlled drug

• TBTQ-CB6DOX. Spermine (SM), an aliphatic polyamine overexpressed in some cancer cells, was expected to exhibit a higher binding affinity to the negatively charged TBTQ-CB6 host, because it exists mainly in a four positively charged form at physiological pH (about 7) [30][31]. Thus, SM was chosen as a

• (10 mL) of compound 2 (0.50 g, 0.36 mmol), 40% aqueous sodium hydroxide was added. The mixture was heated under reflux for 12 h. The solvent was removed by distillation and the residue was dissolved in water and the pH of the solution was adjusted to 2 with hydrochloric acid. The resulting precipitate

Substituent effect on TADF properties of 2-modified 4,6-bis(3,6-di-tert-butyl-9-carbazolyl)-5-methylpyrimidines

• Irina Fiodorova,
• Tomas Serevičius,
• Rokas Skaisgiris,
• Saulius Juršėnas and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 497–507, doi:10.3762/bjoc.18.52

• for compounds with stronger CT emission (e.g., compounds 1 and 4). The phosphorescence (PH) spectra of the carbazole–pyrimidine TADF compounds were rather intriguing. 10 K PH spectra of compounds tCbz-mPYR, 1, 3, 5, and 6 clearly resembled that of individual tCbz units, peaking at about 418 nm [29

• ], while for the rest of the compounds the PH spectra were red-shifted, though still maintaining the vibronic structure. However, the closer inspection of the PH spectra, see Figure S29 in Supporting Information File 1, revealed that all PH spectra coincided with that of the tCbz unit. Actually, the lowest

Comparative study of thermally activated delayed fluorescent properties of donor–acceptor and donor–acceptor–donor architectures based on phenoxazine and dibenzo[a,j]phenazine

• Saika Izumi,
• Prasannamani Govindharaj,
• Anna Drewniak,
• Paola Zimmermann Crocomo,
• Satoshi Minakata,
• Leonardo Evaristo de Sousa,
• Piotr de Silva,
• Przemyslaw Data and
• Youhei Takeda

Beilstein J. Org. Chem. 2022, 18, 459–468, doi:10.3762/bjoc.18.48

• (Figure 2b), suggesting that these emissions have a mixed character of localized (1LE) and charge-transfer state (1CT, Figure 3b). The emission from the T1 state (phosphorescence, PH) at a low temperature (10 K) with the energy of ET1 = 2.26 eV showed a similar spectral shape to the phosphorescence

Synthesis of 3,4,5-trisubstituted isoxazoles in water via a [3 + 2]-cycloaddition of nitrile oxides and 1,3-diketones, β-ketoesters, or β-ketoamides

• Md Imran Hossain,
• Md Imdadul H. Khan,
• Seong Jong Kim and
• Hoang V. Le

Beilstein J. Org. Chem. 2022, 18, 446–458, doi:10.3762/bjoc.18.47

• phosphate buffer under weakly acidic conditions (pH 4.0) at room temperature for 15–24 h and generated 3,5-disubstituted isoxazolines and 3,4,5-trisubstituted isoxazoles in good yields (Figure 1) [28]. Notably, no metal catalysts were used in this method. The development of organic reactions in water not

• % methanol (Table 1, entry 15); in these cases, compound 4 was obtained in excellent yields (70% yield and 95% yield, respectively). Compound 4 was also formed almost exclusively in 76% yield when the reaction was run in phosphate buffer (pH 7.4) in the presence of 5% methanol with 10 mol % of DIPEA (Table 1

• corresponding ketone (10 mmol) in ethyl acetate (20 mL). The reaction mixture was stirred at rt for 12 h. After the reaction was complete, as indicated by TLC, the mixture was carefully treated with 10% aqueous NH4Cl (30 mL) and the pH adjusted to 5 with a solution of hydrochloric acid (3 M). The aqueous phase

Cs₂CO₃-Promoted reaction of tertiary bromopropargylic alcohols and phenols in DMF: a novel approach to α-phenoxyketones

• Ol'ga G. Volostnykh,
• Olesya A. Shemyakina,
• Anton V. Stepanov and
• Igor' A. Ushakov

Beilstein J. Org. Chem. 2022, 18, 420–428, doi:10.3762/bjoc.18.44

• (2i)). Addition of water to the reaction mixture also reduces the pH of the medium and simultaneously increases the concentration of hydroxide ions, therefore, diphenoxyketones 5 were not produced and dihydroxyketones 8 were formed as side products in these cases. Among the approaches to produce α

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

• ]. Different NbSBA-15 catalysts were evaluated and with the optimized reaction conditions, menadione (10) was synthetized in 100% conversion and 97.3% selectivity using NbSBA-15(2.2 pH) and H2O2 [69]. Sulman and co-workers, for instance, reported the synthesis of menadione (10) using supercritical (SC) carbon

Regioselectivity of the S_EAr-based cyclizations and S_EAr-terminated annulations of 3,5-unsubstituted, 4-substituted indoles

• Jonali Das and
• Sajal Kumar Das

Beilstein J. Org. Chem. 2022, 18, 293–302, doi:10.3762/bjoc.18.33

• substrates 20. Noteworthy is that substrates bearing an indolyl N–Ph or N–Boc moiety (instead of free indolyl N–H) failed to deliver the corresponding final cyclized products. The authors attributed this failure to the indole C3 position’s reduced nucleophilicity which thwarted the Michael addition step. In

New efficient synthesis of polysubstituted 3,4-dihydroquinazolines and 4H-3,1-benzothiazines through a Passerini/Staudinger/aza-Wittig/addition/nucleophilic substitution sequence

• Long Zhao,
• Mao-Lin Yang,
• Min Liu and
• Ming-Wu Ding

Beilstein J. Org. Chem. 2022, 18, 286–292, doi:10.3762/bjoc.18.32

• -azidobenzaldehyde (1a), benzoic acid (2a) and tert-butyl isocyanide (3a) as the reactants (Scheme 2). When a mixture of 1a, 2a, and 3a in CH2Cl2 was stirred at room temperature for 48 h, the three-component Passerini reaction was carried out smoothly and the azide 4a (R = Ph) was finally obtained in 87% yield

• isocyanates (Table 2, compounds 8a–l, R3 = Ph, 4-ClC6H4, 3-MeC6H4, 4-MeC6H4 and 4-CF3OC6H4) were used, good yields (69–86%) of the products were obtained, whereas moderate yields (54–57%) were obtained when the more steric secondary amines were utilized (Table 2, compound 8m and 8n, NR4R5 = N(Cy)2, N(iPr)2

• dialkylamines were utilized (Table 3, compounds 11l and 11m, NR4R5 = N(Cy)2, N(iPr)2). In cases when phenylmethylamine (compounds 11n and 11o, NR4R5 = N(Ph)Me) was used, 51–56% yields of the products were obtained, but when diphenylamine was used, no product was obtained (compound 11p, NR4R5 = NPh2). Conclusion

Recent developments and trends in the iron- and cobalt-catalyzed Sonogashira reactions

• Surendran Amrutha,
• Sankaran Radhika and
• Gopinathan Anilkumar

Beilstein J. Org. Chem. 2022, 18, 262–285, doi:10.3762/bjoc.18.31

• latter with salts of Pd(II) and Co(II) in ethylene glycol and water at pH 11 afforded the desired PdCo nanoparticles-3D graphene nanocomposite. The catalyst was then studied in the Sonogashira coupling reaction of arylacetylenes and aryl halides in the presence of various bases and solvents. The maximum