(Bio)isosteres of ortho- and meta-substituted benzenes

• H. Erik Diepers and
• Johannes C. L. Walker

Beilstein J. Org. Chem. 2024, 20, 859–890, doi:10.3762/bjoc.20.78

• -workers, and was accessed over 8 steps from diene 161 (Scheme 17A) [51]. Diels–Alder reaction of diene 161 and di-tert-butyl azodicarboxylate (160) followed by palladium-assisted elimination of acetic acid gave diene 162. A sequence of 4π-electrocyclisation and electrophilic transcarbamation (to 163

Ortho-ester-substituted diaryliodonium salts enabled regioselective arylocyclization of naphthols toward 3,4-benzocoumarins

• Ke Jiang,
• Cheng Pan,
• Limin Wang,
• Hao-Yang Wang and
• Jianwei Han

Beilstein J. Org. Chem. 2024, 20, 841–851, doi:10.3762/bjoc.20.76

• advantage, facilitating the formation of two or more chemical bonds in a step-economic manner [9][10][11][12][13]. In a prior study, we reported a palladium-catalyzed efficient activation of both C–I bond and the adjacent C–H bond of diaryliodonium salts in the formation of 4,5-benzocoumarin derivatives

• -benzocoumarin skeletons in the presence of palladium catalysts (Scheme 1b). Furthermore, Olofsson and colleagues described an unprecedented reaction pathway using ortho-fluoro-substituted diaryliodonium salts bearing strong electron-withdrawing groups, leading to novel diarylations of N-, O-, and S-nucleophiles

Advancements in hydrochlorination of alkenes

• Daniel S. Müller

Beilstein J. Org. Chem. 2024, 20, 787–814, doi:10.3762/bjoc.20.72

• functional group tolerance. Yang reported a hydrochlorination promoted by visible light over platinum, gold, and palladium supported on zirconia [74]. The reaction demonstrated moderate efficiency, yielding an 85:15 mixture of products 100 and 126 with low conversion (Scheme 20). The use of hydrochloric acid

• necessary [93]. In 2022, Liu reported a palladium-catalyzed chain walking–hydrochlorination reaction [94]. While the concept of chain walking is well-established [95], the subsequent reaction of terminal palladium metal with a chlorine electrophile can be considered innovative. This review specifically

• , requiring four steps, coupled with the expense of the palladium catalyst. Interestingly, when the hydroxy group in L3 was protected, the chemoselectivity of the reaction was poor, resulting in a 1:2 mixture of the desired chloride and the corresponding terminal alkene. Liu and colleagues put forth the

Regioselective quinazoline C2 modifications through the azide–tetrazole tautomeric equilibrium

• Dāgs Dāvis Līpiņš,
• Andris Jeminejs,
• Una Ušacka,
• Anatoly Mishnev,
• Māris Turks and
• Irina Novosjolova

Beilstein J. Org. Chem. 2024, 20, 675–683, doi:10.3762/bjoc.20.61

• form can be in either the azide (17e, 17f) or tetrazole form (17a–d). With derivatives 17e,f in hand, the reduction of the azido group in the C4 position was carried out by bubbling hydrogen through the solution in the presence of palladium on charcoal. In the last step, the product was acidified with

Palladium-catalyzed three-component radical-polar crossover carboamination of 1,3-dienes or allenes with diazo esters and amines

• Geng-Xin Liu,
• Xiao-Ting Jie,
• Ge-Jun Niu,
• Li-Sheng Yang,
• Xing-Lin Li,
• Jian Luo and
• Wen-Hao Hu

Beilstein J. Org. Chem. 2024, 20, 661–671, doi:10.3762/bjoc.20.59

• -light-mediated palladium-catalyzed three-component radical-polar crossover carboamination of 1,3-dienes or allenes with diazo esters and amines, affording unsaturated γ- and ε-amino acid derivatives with diverse structures. In this methodology, the diazo compound readily transforms into a hybrid α-ester

• multicomponent reaction protocol. Keywords: carboamination; diazo chemistry; palladium catalysis; radical-polar crossover; three-component reaction; Introduction Since the discovery of the existence of non-canonical amino acids (AAs) in organisms, such structural motifs have attracted considerable attention

• be difficult to achieve using either radical or polar chemistry alone. In recent years, Gevorgyan, Glorius, Huang and their co-workers reported elegant examples of the carboamination of 1,3-dienes with unactivated alkyl halides and amines under photoinduced palladium catalysis via a radical-polar

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

• practicable and robust synthetic route enabling us to carry out a broad SAR study. Initial attempts to prepare 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines 7a and 7b using hydrogen and palladium on charcoal under elevated pressure did not show any conversion of the starting material (Table 1, entries 1 and 2

• -(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

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

• zinc in the apical position of the porphyrins (Figure 15c). Upon the addition of Pd(II), the two pyridine moieties prefer to coordinate the palladium which leads to a 180° rotation motion and confers a cis-conformation to the system. This motion positions the porphyrin units face-to-face and allows

Ligand effects, solvent cooperation, and large kinetic solvent deuterium isotope effects in gold(I)-catalyzed intramolecular alkene hydroamination

• Ruichen Lan,
• Brock Yager,
• Yoonsun Jee,
• Cynthia S. Day and
• Amanda C. Jones

Beilstein J. Org. Chem. 2024, 20, 479–496, doi:10.3762/bjoc.20.43

• molecule of amine delivers a proton to the alkylgold intermediate (for protodeauration). In a platinum-catalyzed hydroamination, a protodemetalation pathway is supported by kinetics and reactivity studies on generated platinum alkyl intermediates [46]. In a palladium-catalyzed hydroamination, a

• protodemetalation pathway is also supported by kinetics and reactivity studies on generated palladium alkyl intermediates [47]. Formation of alkylgold intermediates is known to proceed with anti-attack [27] and the stereospecificity observed in deuterium-labeled intermediates was used as an argument for

• involvement in proton transfer at the transition state [78]. In systems where protodemetalation is rate determining, a metal-carbon bonded intermediate is allegedly characterized, as in the case of a related palladium-catalyzed hydroamination [47], and a propargylamide cyclization [44]. In our studies, the

Mono or double Pd-catalyzed C–H bond functionalization for the annulative π-extension of 1,8-dibromonaphthalene: a one pot access to fluoranthene derivatives

• Nahed Ketata,
• Linhao Liu,
• Ridha Ben Salem and
• Henri Doucet

Beilstein J. Org. Chem. 2024, 20, 427–435, doi:10.3762/bjoc.20.37

• palladium-catalyzed direct intermolecular arylation, followed by a direct intramolecular arylation step. As the C–H bond activation of several benzene derivatives remains very challenging, the preparation of fluoranthenes from 1,8-dibromonaphthalene via Suzuki coupling followed by intramolecular C–H

• ; palladium; Introduction Substituted polyaromatics such as fluoranthenes (Figure 1) are widely used in materials chemistry due to their physical properties, and the introduction of a suitable functional group on the appropriate positions of fluoranthenes either allows their photophysical properties to be

• using commercially available substrates and allowing the regioselective introduction of functional groups at the desired positions is still needed. By using Pd-catalyzed double C–H bond functionalization of activated arenes, such as (poly)fluoroarenes, or by combining a palladium-catalyzed

Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters

• Carlos R. Azpilcueta-Nicolas and
• Jean-Philip Lumb

Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35

• substrate and participating in the key bond-forming/breaking steps via substrate–TM interactions [73][74]. This paradigm has been employed in the activation of NHPI esters under photoinduced copper (Cu) and palladium (Pd) catalysis. In 2017, Peters and Fu reported a Cu-catalyzed decarboxylative C(sp3)–N

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• derivative 21 was synthesized in six steps in 14% overall yield from 3-bromothiophene (17, Scheme 7). In the first step, the sulfur atom embedded in the final thiepine ring was introduced via a palladium-catalyzed S-arylation of 3-bromothiophene in the presence of potassium thioacetate, to afford the

Catalytic multi-step domino and one-pot reactions

• Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2024, 20, 254–256, doi:10.3762/bjoc.20.25

• through concerted or stepwise mechanisms. An enantioselective palladium-catalyzed three-component reaction of glyoxylic acid, sulfonamides, and aryltrifluoroborates toward synthetically useful α-arylglycine compounds is described by the Manolikakes group [11]. Moreover, Šebesta and co-workers report a

Metal-catalyzed coupling/carbonylative cyclizations for accessing dibenzodiazepinones: an expedient route to clozapine and other drugs

• Amina Moutayakine and
• Anthony J. Burke

Beilstein J. Org. Chem. 2024, 20, 193–204, doi:10.3762/bjoc.20.19

• (DBDAPs) is disclosed in this article through a palladium and copper-catalyzed amination (Buchwald–Hartwig (B–H) or Chan–Lam (C–L)) followed by a palladium-catalyzed intramolecular aminocarbonylation with Mo(CO)6 as CO surrogate (to avoid toxic CO handling) of readily available o-phenylenediamines and

• via a cross-coupling reaction with NH3 [13]. The reaction was undertaken in the presence of a catalytic amount of a palladium catalyst and afforded a library of dibenzodiazepinones in good to excellent yields (Scheme 1a). In 2013, Zhang et al. developed a synthetic route leading to structurally

• strategy was reported by Laha et al., aiming to access dibenzodiazepinone structures via a double N-arylation of 2-aminobenzamides with 1,2-dihaloarenes using a palladium-based catalytic system [15]. Mechanistic investigations supported the fact that the regioselective N-arylation of the 2-aminobenzamide

Biphenylene-containing polycyclic conjugated compounds

• Cagatay Dengiz

Beilstein J. Org. Chem. 2023, 19, 1895–1911, doi:10.3762/bjoc.19.141

• . In this context, Xia and co-workers drew inspiration from their prior investigations on palladium-catalyzed annulation reactions concerning ladder polymers [37]. They envisioned that by making minor modifications to the starting materials, they could readily access structurally complex POAs. The

• researchers efficiently conducted palladium-catalyzed C–H activated annulation reactions, involving oxanorbornadiene derivative 26 and aryl bromides including dibromoanthracene 27 [38]. Subsequent aromatization reactions were then carried out, resulting in the successful synthesis of the target POAs with high

• 34a-TIPS showed hole mobilities of 0.075 cm2 V−1 s−1 and 0.19 cm2 V−1 s−1, respectively, while the highest value was noted with 34a-TIBS at 0.52 cm2 V−1 s−1. Later on, Xia and his colleagues demonstrated that curved PAH structures can be synthesized by employing their own developed palladium-catalyzed

Aromatic systems with two and three pyridine-2,6-dicarbazolyl-3,5-dicarbonitrile fragments as electron-transporting organic semiconductors exhibiting long-lived emissions

• Karolis Leitonas,
• Brigita Vigante,
• Dmytro Volyniuk,
• Audrius Bucinskas,
• Pavels Dimitrijevs,
• Sindija Lapcinska,
• Pavel Arsenyan and
• Juozas Vidas Grazulevicius

Beilstein J. Org. Chem. 2023, 19, 1867–1880, doi:10.3762/bjoc.19.139

• equiv), tetrakis(triphenylphosphine)palladium(0) (11.6 mg, 0.01 mmol, 0.05 equiv), CuI (1.2 mg, 0.006 mmol, 0.03 equiv) in 2 mL of DMF was degassed with Ar. Then, the appropriate ethynyl derivative (0.24 mmol, 1.2 equiv) and 1 mL of triethylamine were added and the resulting mixture was heated at 90 °C

Thienothiophene-based organic light-emitting diode: synthesis, photophysical properties and application

• Recep Isci and
• Turan Ozturk

Beilstein J. Org. Chem. 2023, 19, 1849–1857, doi:10.3762/bjoc.19.137

• ), dimesitylboronfluoride (90%, Sigma-Aldrich), 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (Sigma-Aldrich), tetrakis(triphenylphosphine)palladium(0) (Pd(PPh3)4, 99%, Sigma-Aldrich), were used as received. Diethyl ether and THF were dried over metallic sodium. Dimethylformamide (HPLC grade) was stored over activated molecular

Synthetic approach to 2-alkyl-4-quinolones and 2-alkyl-4-quinolone-3-carboxamides based on common β-keto amide precursors

• Yordanka Mollova-Sapundzhieva,
• Plamen Angelov,
• Danail Georgiev and
• Pavel Yanev

Beilstein J. Org. Chem. 2023, 19, 1804–1810, doi:10.3762/bjoc.19.132

• of methods for their synthesis is a very active area of research. Recent contributions to the synthesis of 4-quinolones made use of phosphine-mediated redox cyclization of 1-(2-nitroaryl)prop-2-ynones [39], palladium-catalyzed carbonylative cyclization of 2-bromonitrobenzenes and alkynes [40], TsCl

• , limiting the reaction time to 60–90 min under these conditions allowed some of the N-hydroxy derivatives 4 to be isolated in good yield (Table 5), even though it did not entirely prevent the formation of products 5. Palladium catalysis was not appropriate for the hydrogenation of compounds 3f and 3g

• , because of concomitant reduction at the C–Cl bond. Intermediates 6, similarly to compounds 3, gave mixtures of products 7/8 under palladium-catalyzed transfer hydrogenation conditions. In contrast to 3, however, limiting the reaction time here did not help to develop a preparatively useful procedure for a

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

• 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

• (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

• geometry with the cobalt(II) positioned slightly above the N4 donor plane. The X-ray structure of 18b-Co exhibited a similar Pacman motif as its palladium analogue, with the cobalt(II) cation residing in a square-planar environment. The exploitation of a similar synthetic methodology allowed for preparing

Synthesis of 7-azabicyclo[4.3.1]decane ring systems from tricarbonyl(tropone)iron via intramolecular Heck reactions

• Aaron H. Shoemaker,
• Elizabeth A. Foker,
• Elena P. Uttaro,
• Sarah K. Beitel and
• Daniel R. Griffith

Beilstein J. Org. Chem. 2023, 19, 1615–1619, doi:10.3762/bjoc.19.118

• vast body of knowledge built from many synthetic campaigns towards the Strychnos alkaloids [15]. Several combinations of palladium catalyst, base, and other additives were applied to our system (see Table 1, entries 1–4). Reaction conditions such as those deployed to great effect by Rawal [16] (Table 1

• cleanly according to TLC analysis, but the isolated yield of the intramolecular Heck product was low, perhaps due to instability of one of the intermediate palladium complexes and/or a slow olefin insertion step. Moreover, the product was obtained as an inseparable mixture of the allylic carbamate 18 and

Synthesis and biological evaluation of Argemone mexicana-inspired antimicrobials

• Jessica Villegas,
• Bryce C. Ball,
• Katelyn M. Shouse,
• Caleb W. VanArragon,
• Ashley N. Wasserman,
• Hannah E. Bhakta,
• Allen G. Oliver,
• Danielle A. Orozco-Nunnelly and
• Jeffrey M. Pruet

Beilstein J. Org. Chem. 2023, 19, 1511–1524, doi:10.3762/bjoc.19.108

• berberine variants none are as easily modulated to rapidly install substituent diversity [31][43][44][45][46][47][48]. The method deemed most amenable to varying substituents involves substituted 2-bromo-1-aminonaphthalenes which are used in subsequent palladium cross-coupling reactions [45]. As such, our

N-Sulfenylsuccinimide/phthalimide: an alternative sulfenylating reagent in organic transformations

• Fatemeh Doraghi,
• Seyedeh Pegah Aledavoud,
• Mehdi Ghanbarlou,
• Bagher Larijani and
• Mohammad Mahdavi

Beilstein J. Org. Chem. 2023, 19, 1471–1502, doi:10.3762/bjoc.19.106

• succeeded in synthesizing various diaryl(alkyl) sulfides 5 through the sulfenylation of unactivated arenes 4 with an electrophilic sulfur reagent in the presence of a palladium catalyst (Scheme 3) [45]. In the second phase, dibenzothiophene derivatives 6 were obtained via subsequent intramolecular arylation

• this work. In 2018, Anbarasan and Chaitanya developed an efficient approach for the C–H bond functionalization of aryl compounds containing a directing group using N-(thioaryl)phthalimides 14 in the presence of a palladium catalyst (Scheme 15) [53]. The thiolation occurred in the presence of Pd(OAc)2

• , respectively. It should be noted that the use of a palladium catalyst was essential for the cross-coupling reaction between 1’’’ and 74. Also, the presence of ZnCl2 could facilitate the cleavage of the N–S bond. In the case of amines and thiols, there was no need for a metal catalyst for the formation of S–N

One-pot nucleophilic substitution–double click reactions of biazides leading to functionalized bis(1,2,3-triazole) derivatives

• Hans-Ulrich Reissig and
• Fei Yu

Beilstein J. Org. Chem. 2023, 19, 1399–1407, doi:10.3762/bjoc.19.101

• transformation into divalent carbohydrate mimetics turned out to be a difficult task. We started the experiments with the hydrogenolysis of bicyclic 1,2-oxazin-4-ol 19 as simple model compound (Scheme 7). A methanol solution of 19 under an atmosphere of hydrogen was stirred for 17 h in the presence of palladium

• -triazole) 21. It turned out that the hydrogenolysis of this compound was very capricious and (in part) depended on the batch of palladium on carbon used. In most cases, incomplete consumption of starting material was observed, even after long reaction time. The best result is depicted in Scheme 8 (reaction

• 1), when after five days of hydrogenolysis and 0.8 equivalents of palladium at least 40% of impure divalent aminopyran derivative 25 was isolated. The major component of the isolated material is certainly fitting to the proposed structure according to the NMR data and their comparison with related

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

Radical ligand transfer: a general strategy for radical functionalization

• David T. Nemoto Jr,
• Kang-Jie Bian,
• Shih-Chieh Kao and
• Julian G. West

Beilstein J. Org. Chem. 2023, 19, 1225–1233, doi:10.3762/bjoc.19.90

• literature examples of nitrate oxidation of different transition metals, such as palladium. Control reactions further supported this proposal, including the inability of alternative Fe(III) salts (e.g., FeCl3) to form more than stoichiometric azide product in the absence of added nitrate. We believe this

Copper-catalyzed N-arylation of amines with aryliodonium ylides in water

• Kasturi U. Nabar,
• Bhalchandra M. Bhanage and
• Sudam G. Dawande

Beilstein J. Org. Chem. 2023, 19, 1008–1014, doi:10.3762/bjoc.19.76

• development since the pioneering work by Ullmann [13] and Goldberg [14]. Despite the significant advances, the main limitations are the harsh reaction conditions such as high temperatures, pressure, and unsustainability which limits their scalability for industrial applications. Further, palladium-catalyzed

• strategies for C–N bond formation have been extensively explored by various research groups for the N-arylation of amines. Specifically, seminal contributions by Buchwald [15] and Hartwig [16] involving the use of palladium complexes as catalysts in the presence of either phosphine or diamine ligands for C–N

• bond formation. However, these methods suffer from limitations such as moisture sensitivity, the requirement of specific ligands, and the use of expensive palladium catalysts [17]. Also, Chan Lam, Evans, and other research groups have developed copper-catalyzed C–N bond formation reactions by careful