Synthesis of fluoroalkenes and fluoroenynes via cross-coupling reactions using novel multihalogenated vinyl ethers

• Yukiko Karuo,
• Keita Hirata,
• Atsushi Tarui,
• Kazuyuki Sato,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2024, 20, 2691–2703, doi:10.3762/bjoc.20.226

• previous study by Thorand [44], we performed the reaction between fluorine-containing vinyl ether 1a and 1.05 equiv of trimethylsilylacetylene (5a) to afford the corresponding enyne 3a in 55% yield (Table 2, entry 1). Cross-coupling utilizing a palladium(II) catalysts containing phosphine ligands produced

• low yields of 3a (Table 2, entries 2 and 3). In the case of palladium(II), which produced good yields of the Suzuki–Miyaura cross-coupling products, only a small amount of 3a was obtained (Table 2, entries 4–8). In particular, when the allylpalladium dichloride dimer was used, Sonogashira coupling

Syntheses and medicinal chemistry of spiro heterocyclic steroids

• Laura L. Romero-Hernández,
• Ana Isabel Ahuja-Casarín,
• Penélope Merino-Montiel,
• Sara Montiel-Smith,
• José Luis Vega-Báez and
• Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

• reaction of mestranol acetate (34) catalysed by a palladium(II) complex, in the presence of p-benzoquinone under carbon monoxide. The authors propose an initial addition of the acetate C=O group onto the triple bond coordinated to palladium, followed by a MeOH attack onto the resulting oxycarbenium, and a

Benzylic C(sp³)–H fluorination

• Alexander P. Atkins,
• Alice C. Dean and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137

• pioneering report into palladium(II)/(IV)-catalysed C–H fluorination of 8-methylquinolines using N-fluoro-2,4,6-trimethylpyridinium tetrafluoroborate as an electrophilic “F+” source under microwave conditions (Figure 5) [39]. Benzylic fluorination was achieved in good yields on three examples, each bearing

Diameter-selective extraction of single-walled carbon nanotubes by interlocking with Cu-tethered square nanobrackets

• Guoqing Cheng and
• Naoki Komatsu

Beilstein J. Org. Chem. 2024, 20, 1298–1307, doi:10.3762/bjoc.20.113

• chromatographic purification due to much lower solubility of 4b compared to 4a. The metal complex of 4b with copper(II) was prepared, because copper(II) exhibited better extraction and separation abilities than cobalt(II) and palladium(II) in the case of Cu-tethered rectangular nanobrackets 1a [11]. Before SWNT

Structure–property relationships in dicyanopyrazinoquinoxalines and their hydrogen-bonding-capable dihydropyrazinoquinoxalinedione derivatives

• Tural N. Akhmedov,
• Ajeet Kumar,
• Daken J. Starkenburg,
• Kyle J. Chesney,
• Khalil A. Abboud,
• Novruz G. Akhmedov,
• Jiangeng Xue and
• Ronald K. Castellano

Beilstein J. Org. Chem. 2024, 20, 1037–1052, doi:10.3762/bjoc.20.92

• . Palladium(II) acetate and anhydrous 1,4-dioxane were purchased from Strem Chemicals or Sigma-Aldrich and used as received. Thin-layer chromatography (TLC) was performed on SiO2-60 F254 aluminum plates with visualization by UV light or staining. Flash column chromatography was performed using Purasil SiO2-60

Carbonylative synthesis and functionalization of indoles

• Alex De Salvo,
• Raffaella Mancuso and
• Xiao-Feng Wu

Beilstein J. Org. Chem. 2024, 20, 973–1000, doi:10.3762/bjoc.20.87

• indole derivatives were obtained by catalyzing the reaction with 5 mol % of Pd(tfa)2 (palladium(II) trifluoroacetate) and 1.5 equivalents of p-benzoquinone as oxidant in a 1:5 DMSO/MeOH solvent mixture at a temperature between 0 °C and 15 °C and, for a time between 48 and 120 hours depending on the

• as ligand, because it was already known that catalysts derived from palladium(II) salts and bidentate nitrogen ligands were highly reactive systems for the reduction of o-nitrostyrenes [28][29][30]. The catalytic system Pd(OAc)2/1,10-phen worked better than Söderberg´s one (Pd(OAc)2/PPh3) under mild

Enantioselective synthesis of β-aryl-γ-lactam derivatives via Heck–Matsuda desymmetrization of N-protected 2,5-dihydro-1H-pyrroles

• Arnaldo G. de Oliveira Jr.,
• Martí F. Wang,
• Rafaela C. Carmona,
• Danilo M. Lustosa,
• Sergei A. Gorbatov and
• Carlos R. D. Correia

Beilstein J. Org. Chem. 2024, 20, 940–949, doi:10.3762/bjoc.20.84

• palladium(II)–N,N-ligand complex (II), to which the pyrrolidine substrate coordinates (III). Next, migratory insertion takes place generating the alkylpalladium species (IV), which upon a sequence of β-elimination (V) and hydride insertion leads to alkylpalladium intermediate (VI). Finally, upon

Synthesis and biological profile of 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines, a novel class of acyl-ACP thioesterase inhibitors

• Jens Frackenpohl,
• David M. Barber,
• Guido Bojack,
• Birgit Bollenbach-Wahl,
• Ralf Braun,
• Rahel Getachew,
• Sabine Hohmann,
• Kwang-Yoon Ko,
• Karoline Kurowski,
• Bernd Laber,
• Rebecca L. Mattison,
• Thomas Müller,
• Anna M. Reingruber,
• Dirk Schmutzler and
• Andrea Svejda

Beilstein J. Org. Chem. 2024, 20, 540–551, doi:10.3762/bjoc.20.46

• -(2-fluorophenyl)[1,3]thiazolo[4,5-b]pyridine (12b, 1.88 g, 4.56 mmol, 1.0 equiv), methylboronic acid (1.13 g, 18.24 mmol, 4.0 equiv), potassium phosphate (1.94 g, 9.12 mmol, 2.0 equiv), palladium(II) acetate (103 mg, 0.46 mmol, 0.1 equiv), and 2-dicyclohexylphosphino-2’,6’-dimethoxybiphenyl (579 mg

Tying a knot between crown ethers and porphyrins

• Maksym Matviyishyn and
• Bartosz Szyszko

Beilstein J. Org. Chem. 2023, 19, 1630–1650, doi:10.3762/bjoc.19.120

• (II) compounds 16-Pd–19-Pd exhibited conformations with the characteristic Pacman clefts, resembling their postulated solution structures and typical square-planar geometry around the palladium(II) centres. Titanium(III), vanadium(III), and chromium(III) complexes were synthesised through salt

• molecule bound to the cobalt(III) outside the Pacman cleft and the crown ether part of the adjacent molecule. The type and properties of the coordination compound formed from 16–19 depended strongly on the size and structure of the crown ether part of the molecule and the transition metal [67]. Palladium

Transition-metal-catalyzed C–H bond activation as a sustainable strategy for the synthesis of fluorinated molecules: an overview

• Louis Monsigny,
• Floriane Doche and
• Tatiana Besset

Beilstein J. Org. Chem. 2023, 19, 448–473, doi:10.3762/bjoc.19.35

• year, the group of Huang reported an elegant and straightforward palladium(II)-catalyzed ortho-selective trifluoromethylthiolation of arenes bearing various directing groups using the nucleophilic trifluoromethylthiolating source AgSCF3 in combination with Selectfluor® as oxidant (Scheme 6, 29 examples

• with AgSCF3 occurs before the oxidation step, generating the palladium(II) complex F. After an oxidative addition in the presence of Selectfluor®, the palladium(IV) intermediate E is generated. Finally, after reductive elimination step, the desired product 12 is released and the catalyst regenerated

• were obtained in 30% and 20% yields, respectively. Several mechanistic experiments revealed that the C(sp2)–H bond activation step was reversible and represented the rate-determining step (KIE = 2.4). First, the chelation of the palladium(II) catalyst with the bidentate directing group, followed by the

Simple synthesis of multi-halogenated alkenes from 2-bromo-2-chloro-1,1,1-trifluoroethane (halothane)

• Yukiko Karuo,
• Atsushi Tarui,
• Kazuyuki Sato,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2022, 18, 1567–1574, doi:10.3762/bjoc.18.167

• functionalized enyne structure that will be useful in various molecular transformations [27][28][29]. On the basis of a previous report, Sonogashira cross-coupling of 2 with trimethylsilylacetylene was performed with a bis(triphenylphosphine)palladium(II) dichloride. The reaction proceeded smoothly to give

An alternative C–P cross-coupling route for the synthesis of novel V-shaped aryldiphosphonic acids

• Stephen J. I. Shearan,
• Enrico Andreoli and
• Marco Taddei

Beilstein J. Org. Chem. 2022, 18, 1518–1523, doi:10.3762/bjoc.18.160

• ][25][26]. These catalytic cross-coupling reactions tend to follow similar pathways to the Michaelis–Arbuzov reaction, with the inclusion of a catalytic intermediate step. A number of suitable catalysts have been identified, ranging from nickel(II) bromide and nickel(II) chloride, to palladium(II

• ) acetate and palladium(II) chloride [23][27][28]. Reactions involving these catalysts are most often carried out at high temperatures, usually in excess of 160 °C, and involve slow dropwise addition of the trialkyl phosphite to the substrate [23]. In the search for milder reaction conditions, a new

Mechanochemical halogenation of unsymmetrically substituted azobenzenes

• Dajana Barišić,
• Mario Pajić,
• Ivan Halasz,
• Darko Babić and
• Manda Ćurić

Beilstein J. Org. Chem. 2022, 18, 680–687, doi:10.3762/bjoc.18.69

• ; N-halosuccinimide; palladium(II); Introduction Electrophilic aromatic substitution [1][2][3] and ligand-directed transition-metal-catalyzed reactions [4][5][6][7][8] are among the most widely used synthetic approaches for the preparation of halogenated arenes. They are important precursors in cross

Heteroleptic metallosupramolecular aggregates/complexation for supramolecular catalysis

• Prodip Howlader and
• Michael Schmittel

Beilstein J. Org. Chem. 2022, 18, 597–630, doi:10.3762/bjoc.18.62

• metal–ligand motifs often center about iridium, ruthenium, rhodium etc. [25], the dynamic ones are constructed using copper(I), zinc(II), cadmium(II), iron(II), palladium(II), etc. as metal ions due to their more rapid ligand exchange rates [24][25][26]. The strategies to prepare inert vs dynamic

• , since a variety of heteroleptic aggregation protocols have been developed by Schmittel [37] (for copper(I), zinc(II), cadmium(II), mercury(II) ions) and Yoshizawa/Fujita [38] (for palladium(II) ion) that involve pyridine-derived ligands. Highly innovative are the approaches for terpyridine-based

• complexes by Chan using complementary ligand binding [39], sometimes combined with conformational regulation [40], and of Newkome/Li [41] applying mainly geometric complementarity [42]. Clever utilized shape complementarity [21] for building heteroleptic palladium(II) cages whereas Crowley developed a

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

• one of the most studied and used oxidants has been H2O2. Yamaguchi and co-workers described the oxidation of 16 with aqueous H2O2 in the presence of a palladium(II)-polystyrene sulfonic acid resin (Table 1, entry 4) [50]. According to the authors, in the absence of the catalysts, the oxidation took

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

• Avanzada (ORFEO-CINQA) and Instituto de Síntesis Orgánica (ISO), PO Box 99, 03080 Alicante, Spain 10.3762/bjoc.17.192 Abstract A series of novel palladium(II) and nickel(II) complexes of multifunctionalized aroylaminocarbo-N-thioylpyrrolinates were synthesized and characterized by analytical and

• results of its corresponding nickel(II) [18] and palladium(II) [19][20] complexes with the analogous tests obtained in the case of having a benzylic substituent at the same position. Also, DFT calculations are run in order to study the conformational analysis of the synthetized complexes. Results and

• -dipolar cycloaddition [16][21][22], were submitted to the reaction with benzoyl isothiocyanate in refluxing acetonitrile to obtain compounds L1, L2 and L3 in good yields [16][21]. Due to the very low biological activity of these ligands by themselves, the chelation with nickel(II) and palladium(II) was

Recent advances in the syntheses of anthracene derivatives

• Giovanni S. Baviera and
• Paulo M. Donate

Beilstein J. Org. Chem. 2021, 17, 2028–2050, doi:10.3762/bjoc.17.131

• anthracene derivatives 33. The strategy involved a palladium(II)-catalyzed tandem transformation with diphenyl carboxylic acids 31 and acrylates 32 (Scheme 7) [41]. This new methodology involved a carboxyl-directed C–H alkenylation, a carboxyl-directed secondary C–H activation, an intramolecular C–C-bond

• employed palladium(II) acetate and visible light under O2 in the reactions between ethyl acrylate (192) and substituted diaryl carboxylic acids 193, to produce anthraquinones 194 in low to moderate yields (30–68%). In a direct comparison with the methodology proposed by Hong for the synthesis of

• multicomponent reactions employing 2-hydroxy-1,4-naphthoquinone (186), β-naphthol (181), and aromatic aldehydes. Synthesis of substituted anthraquinones catalyzed by an AlCl3/MeSO3H system. Palladium(II)-catalyzed/visible light-mediated synthesis of anthraquinones. [4 + 2] Anionic annulation reaction for the

[2 + 1] Cycloaddition reactions of fullerene C₆₀ based on diazo compounds

• Yuliya N. Biglova

Beilstein J. Org. Chem. 2021, 17, 630–670, doi:10.3762/bjoc.17.55

• fullerene ligands 66–68. Synthesis of C60-attached SCS pincer–palladium(II) complex 70. Synthesis of spiro-linked C-glycosides of fullerenes 71 and 72. Synthesis of quinone-substituted methanofullerene derivatives 76–78. Synthesis of spiroannelated methanofullerenes 79–81. The synthetic route for

The preparation and properties of 1,1-difluorocyclopropane derivatives

• Kymbat S. Adekenova,
• Peter B. Wyatt and
• Sergazy M. Adekenov

Beilstein J. Org. Chem. 2021, 17, 245–272, doi:10.3762/bjoc.17.25

• cleavage by the use of either palladium(II) oxide or Raney nickel as the catalyst (Scheme 66) [116]. Butylbenzene (152) and 2-fluoro-1-phenylbutane (153) were the main products, although the unsaturated intermediates 154 and 155 were also detected. The contribution of the fluorine substituents to the

Progress in the total synthesis of inthomycins

• Bidyut Kumar Senapati

Beilstein J. Org. Chem. 2021, 17, 58–82, doi:10.3762/bjoc.17.7

•  19). For the synthesis of inthomycin B ((+)-2), a Suzuki coupling reaction between (E,E)-128 and (Z)-(+)-130a was performed in the presence of palladium(II) acetate, triphenylphosphine, and aqueous sodium carbonate to give (E,E,Z)-triene (+)-131 selectively in 64% yield. Treatment of triene (+)-131

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

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

• palladium(II) was carried out in the presence of PdCl2(MeCN)2 in a stepwise manner, confirmed by UV–vis spectroscopic technique. The cyclopentadienyl (Cp) ligand has its own identity in the field of organometallic chemistry as a plethora of transition metal complexes contain this moiety in their structures

Synthesis of novel multifunctional carbazole-based molecules and their thermal, electrochemical and optical properties

• Nuray Altinolcek,
• Ahmet Battal,
• Mustafa Tavasli,
• William J. Peveler,
• Holly A. Yu and
• Peter J. Skabara

Beilstein J. Org. Chem. 2020, 16, 1066–1074, doi:10.3762/bjoc.16.93

• potassium acetate (KOAc) and dichlorobis(triphenylphosphine)palladium(II) in 1,4-dioxane [36][37]. Upon chromatography (9-hexylcarbazole-3-yl)boronic acid pinacol ester (5) was obtained as a liquid in good yield. (9-Hexylcarbazole-3-yl)boronic acid pinacol ester (5) was subjected to Suzuki–Miyaura reaction

• either with 2-bromopyridine-4-carbaldehyde (6a) or 2-bromopyridine-5-carbaldehyde (6b) in the presence of potassium carbonate and bis(triphenylphosphine)palladium(II) dichloride in tetrahydrofuran [2]. Upon repeated purification by chromatography, compounds 7a and 7b were obtained as liquids in good

• ), 0.86 (t, J = 7.0 Hz, 4H). (9-Hexylcarbazole-3-yl)boronic acid pinacol ester (5): 5 was synthesised as reported previously [36][37]. Bis(pinacolato)diboron (423 mg, 1.7 mmol), potassium acetate (446 mg, 4.5 mmol) and dichlorobis(triphenylphosphine)palladium(II) (35 mg, 0.05 mmol) catalyst were added to

Bipyrrole boomerangs via Pd-mediated tandem cyclization–oxygenation. Controlling reaction selectivity and electronic properties

• Liliia Moshniaha,
• Marika Żyła-Karwowska,
• Joanna Cybińska,
• Piotr J. Chmielewski,
• Ludovic Favereau and
• Marcin Stępień

Beilstein J. Org. Chem. 2020, 16, 895–903, doi:10.3762/bjoc.16.81

• (NDA) and naphthalenemonoimide (NMI) moieties. The double C–H bond activation initially used palladium(II) acetate in acetic acid as the coupling system. The subsequent screening revealed, however, that a catalytic coupling could be also achieved in the presence of silver(I) carbonate as the

• -dipyrrolylpropanes (NDA3H, NMI3H) were reacted with palladium(II) acetate in acetic acid to furnish the expected bipyrrole dilactams in 43–53% yields (Table 1, entries 1, 6, 11 and 17). Remarkably, it was found that cNMI2O and cNMI3O were obtained along with the intermediate α-unsubstituted boomerangs, cNMI2H and

• that the coupling and α-oxygenation can also be achieved with 1 equiv of Pd(OAc)2 in the presence of 2 equiv of silver carbonate. Nevertheless, Ag2CO3 oxidation provided lower yields and the efficiency of this variant was dramatically diminished when the loading of palladium(II) acetate was decreased

Synthesis of C₇₀-fragment buckybowls bearing alkoxy substituents

• Yumi Yakiyama,
• Shota Hishikawa and
• Hidehiro Sakurai

Beilstein J. Org. Chem. 2020, 16, 681–690, doi:10.3762/bjoc.16.66

• above results strongly suggested the existence of an equilibrium between the intermediates corresponding to products 5b and 5c. A possible mechanism is shown in Scheme 2 [21][22][23][24][25]. After the oxidative addition of 4b to Pd0 to generate intermediate A, the neutral palladium(II) intermediate B