Intramolecular C–H arylation of pyridine derivatives with a palladium catalyst for the synthesis of multiply fused heteroaromatic compounds

• Yuki Nakanishi,
• Shoichi Sugita,
• Kentaro Okano and
• Atsunori Mori

Beilstein J. Org. Chem. 2024, 20, 3256–3262, doi:10.3762/bjoc.20.269

• arylation precursors 1a–c. Palladium-catalyzed intramolecular direct arylation for synthesizing 8a and 8b and the X-ray crystallographic structure of 8a. Studies on the reaction conditions for 2a from 1a. Pd-catalyzed C–H arylation of heteroarenes. Supporting Information Accession code CCDC 2227450

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

• activation has also been investigated to provide a complementary method. Using the most appropriate synthetic route and substrates, it is possible to introduce the desired functional groups at positions 7–10 on fluoranthenes. Keywords: catalysis; C–H bond functionalization; direct arylation; fluoranthenes

• (Table 1, entries 14–16). The decisive influence of the base for this reaction is probably due to a concerted metalation–deprotonation mechanism [27][28][29][30]. Then, the scope of the Pd-catalyzed direct arylation for access to fluoranthenes was investigated (Scheme 2). The first step of the catalytic

• ) catalyst with KOPiv base in DMA at 150 °C – and the expected product 2 was obtained in 68% yield. Fluorobenzenes bearing methoxy, methyl, chloro or cyclopropanecarbonyl substituents in the para-position also gave the desired fluoranthenes 3–6 in moderate yields. The Pd-catalyzed direct arylation of 1

Facile and diastereoselective arylation of the privileged 1,4-dihydroisoquinolin-3(2H)-one scaffold

• Dmitry Dar’in,
• Grigory Kantin,
• Alexander Bunev and
• Mikhail Krasavin

Beilstein J. Org. Chem. 2022, 18, 1070–1078, doi:10.3762/bjoc.18.109

• literature. Lured by the prospects of applying a diazo chemistry route to an expedited synthesis of hitherto undescribed 1,2,4-trisubstituted 1,4-DHIQs 9 from 11, we set off to investigate the obtainability of 10 from 11 by the Regitz [21] diazo transfer and the usage of 10 in acid-promoted direct arylation

Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds

• Alemayehu Gashaw Woldegiorgis and
• Xufeng Lin

Beilstein J. Org. Chem. 2021, 17, 2729–2764, doi:10.3762/bjoc.17.185

• ) (Scheme 2). The electronic properties of the substituents on the 2-naphthylamine showed remarkable effects on the chemical yield but had negligible impact on the enantioselectivity [42]. The direct arylation reaction of quinones 6 and 2-naphthols 7 was described by Tan and co-workers in 2015. The

• presence of a chiral phosphoric acid, the azo group has recently been revealed to be a useful moiety that may efficiently activate an aromatic ring for formal nucleophilic aromatic substitution, resulting in the cleavage of the aryl C–H bond and direct arylation of the nucleophile [58]. In 2018, Tan and co

• type of axially chiral indoles 27 (Scheme 10) bearing aniline groups by direct arylation and rearrangement in moderate to good yields with excellent enantioselectivities of mostly 99% ee (Scheme 9b) [59]. The electronic properties and position of the substituents on the azobenzene ring did not affect

Photoredox catalysis in nickel-catalyzed C–H functionalization

• Lusina Mantry,
• Rajaram Maayuri,
• Vikash Kumar and
• Parthasarathy Gandeepan

Beilstein J. Org. Chem. 2021, 17, 2209–2259, doi:10.3762/bjoc.17.143

• , which is similar to that of Figure 4. The robustness of the photoredox nickel catalysis was further demonstrated by a protocol for the direct arylation of inert aliphatic C‒H bonds [62]. Thus, MacMillan and co-workers employed tetrabutylammonium decatungstate [(W10O32)4−·4(Bu4N+)] (TBADT) as an

• nickel(I) species 8-VII regenerates the active nickel(0) catalytic species 8-IV and the ketone photocatalyst 24. In a related process, Rueping employed 4,4’-dichlorobenzophenone (27) as the HAT photocatalyst along with a nickel catalyst for the direct arylation of benzylic C–H bonds with aryl bromides 3

A recent overview on the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles

• Pezhman Shiri,
• Ali Mohammad Amani and
• Thomas Mayer-Gall

Beilstein J. Org. Chem. 2021, 17, 1600–1628, doi:10.3762/bjoc.17.114

• reductive elimination occurs in the presence of base to achieve the desired product 119 (Scheme 36) [59]. Direct arylation of disubstituted triazoles 123 with aryl halides 124 using a Pd/C catalyst under solvent-free conditions to give fully decorated triazoles 125 was reported by Farinola et al. Different

Synthesis of 10-O-aryl-substituted berberine derivatives by Chan–Evans–Lam coupling and investigation of their DNA-binding properties

• Peter Jonas Wickhorst,
• Mathilda Blachnik,
• Denisa Lagumdzija and
• Heiko Ihmels

Beilstein J. Org. Chem. 2021, 17, 991–1000, doi:10.3762/bjoc.17.81

• . Nevertheless, it has been recently reported that 9-O-aryl-substituted berberine derivatives can be isolated by an Ullmann-type arylation of a tetrahydroberberrubine and a subsequent oxidation of the primary product to the respective berberine derivatives 2a–i (Figure 1) [31]. So far, a successful direct

• arylation of berberrubine (1b) has not been reported. At the same time, the Chan–Evans–Lam cross coupling has been established as a useful and relatively mild method for metal-mediated arylation of hydroxyarenes [32][33]. Therefore, we proposed that this method may be suitable for the arylation of

Chan–Evans–Lam N1-(het)arylation and N1-alkеnylation of 4-fluoroalkylpyrimidin-2(1H)-ones

• Viktor M. Tkachuk,
• Oleh O. Lukianov,
• Mykhailo V. Vovk,
• Isabelle Gillaizeau and
• Volodymyr A. Sukach

Beilstein J. Org. Chem. 2020, 16, 2304–2313, doi:10.3762/bjoc.16.191

• promising building blocks for further functionalization, including (het)aryl or alkenyl substitution at the N1 atom. However, direct arylation of 1 with aryl halides under Ullmann reaction conditions is a low-efficiency process giving only complex mixtures. It is likely that the harsh thermal conditions

When metal-catalyzed C–H functionalization meets visible-light photocatalysis

• Lucas Guillemard and
• Joanna Wencel-Delord

Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147

• transformation concerned the direct arylation of various aromatic compounds bearing different DGs with aryldiazonium salts (Figure 20). In her initial study in 2005, Sanford reported a similar arylation and diazonium salts were already identified as appropriate coupling partners. However, harsh reaction

• bicoordinating DGs to facilitate C(sp3)–H metalation, Polyzos’s group reported the direct arylation of aliphatic bonds with aryldiazonium salts via a palladium/photoredox dual catalysis (Figure 26) [88]. The method utilized an 8-aminoquinoline-derived bidentate auxiliary, and, in contrast with a vast majority of

• reaction protocol, a range of biaryls was synthesized in moderate to good yields under very mild reaction conditions. Nevertheless, due to regioselectivity issues, this photo-flow direct arylation was mainly limited to symmetrical aryls. The site-selectivity issues could, however, be solved by using

Room-temperature Pd/Ag direct arylation enabled by a radical pathway

• Amy L. Mayhugh and
• Christine K. Luscombe

Beilstein J. Org. Chem. 2020, 16, 384–390, doi:10.3762/bjoc.16.36

• Amy L. Mayhugh Christine K. Luscombe Department of Chemistry, University of Washington, Seattle, WA 98195, USA Department of Materials Science & Engineering, University of Washington, Seattle, WA 98195, USA 10.3762/bjoc.16.36 Abstract Direct arylation is an appealing method for preparing π

• -conjugated materials, avoiding the prefunctionalization required for traditional cross-coupling methods. A major effort in organic electronic materials development is improving the environmental and economic impact of production; direct arylation polymerization (DArP) is an effective method to achieve these

• goals. Room-temperature polymerization would further improve the cost and energy efficiencies required to prepare these materials. Reported herein is new mechanistic work studying the underlying mechanism of room temperature direct arylation between iodobenzene and indole. Results indicate that room

Regioselective Pd-catalyzed direct C1- and C2-arylations of lilolidine for the access to 5,6-dihydropyrrolo[3,2,1-ij]quinoline derivatives

• Hai-Yun Huang,
• Haoran Li,
• Thierry Roisnel,
• Jean-François Soulé and
• Henri Doucet

Beilstein J. Org. Chem. 2019, 15, 2069–2075, doi:10.3762/bjoc.15.204

• an intramolecular Pd-catalyzed direct arylation was examined (Scheme 5). The reaction of compound 2 with 1,2-dibromobenzene in the presence of 2 mol % PdCl(C3H5)(dppb) catalyst and KOAc as base afforded the desired carbazole 27 in moderate yield after 16 h due to a partial conversion of 2. However

• , formyl, acetyl, propionyl, benzoyl, esters, chloro, or acetonitrile on the aryl bromide and the heteroaryl bromides 3- or 4-bromopyridines and 3-bromoquinoline. From these α-arylated lilolidines, a second Pd-catalyzed direct arylation at β-position gave rise to α,β-diarylated lilolidines with two

A review of the total syntheses of triptolide

• Xiang Zhang,
• Zaozao Xiao and
• Hongtao Xu

Beilstein J. Org. Chem. 2019, 15, 1984–1995, doi:10.3762/bjoc.15.194

• for the generation of carbon radicals via single-electron transfer (SET). In 2016, Barriault and co-workers reported a methodology that features the utilization of dimeric gold complex [Au2(dppm)2]Cl2 and ultraviolet A (UV, 365 nm) light to direct arylation of bromide-substituted butenolides or cyclic

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

Diels–Alder cycloadditions of N-arylpyrroles via aryne intermediates using diaryliodonium salts

• Huangguan Chen,
• Jianwei Han and
• Limin Wang

Beilstein J. Org. Chem. 2018, 14, 354–363, doi:10.3762/bjoc.14.23

• derivatives with diaryliodonium salts for pyrrole–aryl coupling products is generating tremendous academic interest in organic synthesis. In 2012, the Zhang and Yu group reported that sodium hydroxide promoted direct arylation of unprotected pyrroles with diaryliodonium salts at the temperature of 80 °C, the

Reactivity of bromoselenophenes in palladium-catalyzed direct arylations

• Aymen Skhiri,
• Ridha Ben Salem,
• Jean-François Soulé and
• Henri Doucet

Beilstein J. Org. Chem. 2017, 13, 2862–2868, doi:10.3762/bjoc.13.278

• examined. The expected product 7 was obtained in a high yield of 81%. Thus, for Pd-catalyzed direct heteroarylations of 2-bromoselenophene, only the heteroarenes containing C–H bonds with low Gibbs free energies of activation [41] should be employed. By contrast, the direct arylation reactions with 2,5

• , respectively. The use of 2-pentyl- and 2-chlorothiophenes also gave the desired products 10 and 11 in high yields. In general, the Pd-catalyzed direct arylation of 3-substituted thiophenes with aryl halides afforded quite regioselectively the C2-arylated thiophenes [30]. A similar regioselectivity was oberved

• C5-position of 2-arylselenophenes containing nitrile, acetyl or chloro substituents on the aryl moiety, which could be easily obtained in good yields from selenophene and aryl bromides via a Pd-catalyzed direct arylation using a reported procedure [33], afforded the 2-aryl-5-bromoselenophenes 15–17

Direct catalytic arylation of heteroarenes with meso-bromophenyl-substituted porphyrins

• Alexei N. Kiselev,
• Olga K. Grigorova,
• Alexei D. Averin,
• Sergei A. Syrbu,
• Oskar I. Koifman and
• Irina P. Beletskaya

Beilstein J. Org. Chem. 2017, 13, 1524–1532, doi:10.3762/bjoc.13.152

• ][11], Suzuki–Miyaura [12][13][14][15] and Stille couplings [16][17][18][19][20][21][22] were successfully applied for this purpose. Direct arylation and alkenylation are modern approaches for the formation of C–C bonds, and the application of these methodologies to porphyrins was widely studied by

Direct arylation catalysis with chloro[8-(dimesitylboryl)quinoline-κN]copper(I)

• Sem Raj Tamang and
• James D. Hoefelmeyer

Beilstein J. Org. Chem. 2016, 12, 2757–2762, doi:10.3762/bjoc.12.272

• Sem Raj Tamang James D. Hoefelmeyer Department of Chemistry, University of South Dakota, 414 E. Clark St., Vermillion, SD 57069, USA 10.3762/bjoc.12.272 Abstract We report direct arylation of arylhalides with unactivated sp2 C–H bonds in benzene and naphthalene using a copper(I) catalyst

• featuring an ambiphilic ligand, (quinolin-8-yl)dimesitylborane. Direct arylation could be achieved with 0.2 mol % catalyst and 3 equivalents of base (KO(t-Bu)) at 80 °C to afford TON ≈160–190 over 40 hours. Keywords: catalysis; C–C coupling; C–H activation; copper; direct arylation; Introduction Coupling

• direct arylation reaction can be achieved with X = halogen, triflate, tosylate [14], B(OH)2 [15][16][17][18][19][20], SnR3 [21], Si(OR)3 [22], or with the use of aryliodonium salts [23]; wherein halogen atoms represent the most cost-effective and atom-efficient functional group. The reactions typically

High performance p-type molecular electron donors for OPV applications via alkylthiophene catenation chromophore extension

• Paul B. Geraghty,
• Calvin Lee,
• Jegadesan Subbiah,
• Wallace W. H. Wong,
• James L. Banal,
• Mohammed A. Jameel,
• Trevor A. Smith and
• David J. Jones

Beilstein J. Org. Chem. 2016, 12, 2298–2314, doi:10.3762/bjoc.12.223

• , K3PO4 (2 M), 80 °C, 16 h, ii) ICl, DCM, 0 °C or NIS, 50:50 CHCl3/CH3CO2H, rt, 2 h. Synthesis of the bithiophene through palladium catalyzed direct arylation, a) i) Pd(OAc)2, PCy3, PivOH, K2CO3, toluene 100 °C, 4 h, 1%, ii) Pd(OAc)2, PPh3, K2CO3, DMF 120 °C, 6 h, 10%, iii) Pd(OAc)2, dppp, KOAc, DMAc 120

Regiocontroled Pd-catalysed C5-arylation of 3-substituted thiophene derivatives using a bromo-substituent as blocking group

• Mariem Brahim,
• Hamed Ben Ammar,
• Jean-François Soulé and
• Henri Doucet

Beilstein J. Org. Chem. 2016, 12, 2197–2203, doi:10.3762/bjoc.12.210

• introduction of aryl substituents at C5-position via Pd-catalysed direct arylation. With 1 mol % of a phosphine-free Pd catalyst, KOAc as the base and DMA as the solvent and various electron-deficient aryl bromides as aryl sources, C5-(hetero)arylated thiophenes were synthesized in moderate to high yields

• , without cleavage of the thienyl C–Br bond. Moreover, sequential direct thienyl C5-arylation followed by Pd-catalysed direct arylation or Suzuki coupling at the C2-position allows to prepare 2,5-di(hetero)arylated thiophenes bearing two different (hetero)aryl units in only two steps. This method provides a

• “green” access to arylated thiophene derivatives as it reduces the number of steps to prepare these compounds and also the formation of wastes. Keywords: aryl bromides; C–H bond activation; catalysis; direct arylation; palladium; thiophenes; Introduction Thiophene derivatives bearing aryl substituents

3,6-Carbazole vs 2,7-carbazole: A comparative study of hole-transporting polymeric materials for inorganic–organic hybrid perovskite solar cells

• Wei Li,
• Munechika Otsuka,
• Takehito Kato,
• Yang Wang,
• Takehiko Mori and
• Tsuyoshi Michinobu

Beilstein J. Org. Chem. 2016, 12, 1401–1409, doi:10.3762/bjoc.12.134

• -EDOT (Scheme 1). We very recently reported the synthesis of the same polymer structures by the microwave-assisted direct arylation polycondensation, but it should be noted that the soluble 2,7-Cbz-EDOT could not be obtained due to undesired side reactions [37]. In contrast, the conventional Stille

Cationic Pd(II)-catalyzed C–H activation/cross-coupling reactions at room temperature: synthetic and mechanistic studies

• Takashi Nishikata,
• Alexander R. Abela,
• Shenlin Huang and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2016, 12, 1040–1064, doi:10.3762/bjoc.12.99

• C–H arylations of arylureas with aryl iodides and arylboronic acids Among the most conceptually attractive approaches to aromatic C–H activation is the efficient synthesis of biaryls through direct arylation reactions. The widespread availability of aryl iodides and arylboronic acids make them

N-Methylphthalimide-substituted benzimidazolium salts and PEPPSI Pd–NHC complexes: synthesis, characterization and catalytic activity in carbon–carbon bond-forming reactions

• Senem Akkoç,
• Yetkin Gök,
• İlhan Özer İlhan and
• Veysel Kayser

Beilstein J. Org. Chem. 2016, 12, 81–88, doi:10.3762/bjoc.12.9

• spectroscopic methods (1H and 13C{1H} NMR, UV–vis, ESI-FTICR-MS, FTIR) and elemental analysis. The PEPPSI Pd–NHC complexes were tested for catalytic activities both in direct arylation and Suzuki–Miyaura cross-coupling reactions. The catalytic activities of benzimidazolium salts were only tested in a Suzuki

Efficient synthesis of π-conjugated molecules incorporating fluorinated phenylene units through palladium-catalyzed iterative C(sp²)–H bond arylations

• Fatiha Abdelmalek,
• Fazia Derridj,
• Safia Djebbar,
• Jean-François Soulé and
• Henri Doucet

Beilstein J. Org. Chem. 2015, 11, 2012–2020, doi:10.3762/bjoc.11.218

• . Palladium-catalyzed desulfitative arylation of heteroarenes allowed in a first step the synthesis of fluoroaryl-heteroarene units in high yields. Then, the next steps involve direct arylation with aryl bromides catalyzed by PdCl(C3H5)(dppb) to afford triad or tetrad heteroaromatic compounds via

• in high yields in only a few steps with the respect of the environment [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. Since the reports on transition metal-catalyzed direct arylation of polyfluorobenzenes by Fagnou (Figure 1b) [26], and others [27][28][29][30][31][32][33

• -catalyzed direct arylation using aryl bromides as coupling partners. Indeed, the regioselectivity of such reaction with these coupling partners needs to be investigated (Schemes 2–4). (2,3,4-Trifluorophenyl)furans 1 and 2 have two and three C–H bonds, respectively, which are susceptible to react under

Polythiophene and oligothiophene systems modified by TTF electroactive units for organic electronics

• Alexander L. Kanibolotsky,
• Neil J. Findlay and
• Peter J. Skabara

Beilstein J. Org. Chem. 2015, 11, 1749–1766, doi:10.3762/bjoc.11.191

• × 10−9 and 9 × 10−9 mol/cm2, respectively. A recent example of the chemical preparation of PT with pendant TTF-units has been reported [53] (Scheme 4) where direct arylation polymerisation of quaterthiophene 13a and 3-(acetoxymethyl)thiophene (13b), followed by acidic hydrolysis of the ester groups in

• prepared by electropolymerisation and post-modification of polymerised PT through iodoalkyl functionality. Synthesis of PT with pendant TTF by post-modification of the polymer prepared by direct arylation. Retrosynthetic scheme for the synthesis of the monomer building block which is required for the

Chiroptical properties of 1,3-diphenylallene-anchored tetrathiafulvalene and its polymer synthesis

• Masashi Hasegawa,
• Junta Endo,
• Seiya Iwata,
• Toshiaki Shimasaki and
• Yasuhiro Mazaki

Beilstein J. Org. Chem. 2015, 11, 972–979, doi:10.3762/bjoc.11.109

• various types of aryl groups. At this point, we have chosen the direct arylation of TTF in the presence of a palladium catalyst as a key reaction for the chiral polymer synthesis (Scheme 2) [22]. Thus, the chiral allenes, (R)-9 or (S)-9, react with an active palladium species, prepared in situ from Pd(OAc