Construction of hexabenzocoronene-based chiral nanographenes

• Ranran Li,
• Di Wang,
• Shengtao Li and
• Peng An

Beilstein J. Org. Chem. 2023, 19, 736–751, doi:10.3762/bjoc.19.54

• )benzene through Co-catalyzed cyclotrimerization in a 45% yield. Then monoiodide NG 49 was obtained through oxidative cyclodehydronation in a high yield. From the heptagon-containing NG 49, Sonogashira coupling with p-tert-butylphenylacetylene (50) afforded 51 in a quantitative yield. Subsequent Diels

• -workers synthesized a helical bilayer NG by using helicene in the initial step as the linker to fuse two HBC units [48]. As shown in Scheme 6, starting from the helical alkyne 54, Sonogashira coupling with 4-tert-butyliodobenzene (55) afforded structure 56 in a 77% yield. Subsequent Diels–Alder reaction

• Sonogashira cross-coupling reaction of phenylacetylene 50 and 1,4-dibromotetrafluorobenzene. The resulting bis[aryl(ethynyl)]tetrafluorobenzene 59 was able to undergo a 2-fold [4 + 2] cycloaddition reaction with cyclopentadienone 2, affording polyaromatic 60 in a 70% yield. The final step was the Scholl

Strategies in the synthesis of dibenzo[b,f]heteropines

• David I. H. Maier,
• Barend C. B. Bezuidenhoudt and
• Charlene Marais

Beilstein J. Org. Chem. 2023, 19, 700–718, doi:10.3762/bjoc.19.51

• relies on a double Sonogashira coupling [(i) and (iii)], reduction (iv), and bromination (v), followed by Buchwald–Hartwig amination (viii) (Scheme 14). While interesting, the reaction has limited substrate scope due to the reliance on a late-stage bromination. To achieve the correct ortho-bromo

• towards dibenzo[b,f]azepines and other dibenzo[b,f]heteropines, and the functionalisation thereof. Modern metal-catalyzed methods to introduce the C–C bridge include the Heck reaction, the Sonogashira reaction, Suzuki coupling and ring-closing metathesis, whereas Buchwald–Hartwig type reactions and Ullman

Synthesis, structure, and properties of switchable cross-conjugated 1,4-diaryl-1,3-butadiynes based on 1,8-bis(dimethylamino)naphthalene

• Semyon V. Tsybulin,
• Ekaterina A. Filatova,
• Alexander F. Pozharskii,
• Valery A. Ozeryanskii and
• Anna V. Gulevskaya

Beilstein J. Org. Chem. 2023, 19, 674–686, doi:10.3762/bjoc.19.49

• –Stephens reaction, method A) and arylacetylenes (Sonogashira reaction, method B). In all cases, even when using a small excess of 8, in addition to the desired monoalkynyl derivative 7, a double alkynylation product 9 was formed (Table 1). The Sonogashira coupling was somewhat more efficient, yielding

Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities

• Jorge de Lima Neto and
• Paulo Henrique Menezes

Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31

• esterification reactions gave the ester 33 which was submitted to a Sonogashira coupling reaction with propargyl alcohol to give the advanced intermediate 34 [34]. Partial hydrogenation of the triple bond in 34 using Lindlar’s catalyst led to the cis-allylic alcohol 35 and subsequent ester hydrolysis led to the

Total synthesis of insect sex pheromones: recent improvements based on iron-mediated cross-coupling chemistry

• Eric Gayon,
• Guillaume Lefèvre,
• Olivier Guerret,
• Adrien Tintar and
• Pablo Chourreu

Beilstein J. Org. Chem. 2023, 19, 158–166, doi:10.3762/bjoc.19.15

• ]) are linear syntheses involving a great number of steps and purifications as well as cryogenic temperatures. Moreover, the introduction of the C=C unsaturation is achieved via a Wittig reaction or a Pd-catalyzed Sonogashira cross-coupling followed by a reduction by a borane reagent, methods which lead

Inline purification in continuous flow synthesis – opportunities and challenges

• Jorge García-Lacuna and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 1720–1740, doi:10.3762/bjoc.18.182

• reported by Pitts and collaborators. This study achieves full removal of metal species after common homogenous catalytic reactions such as a Suzuki–Miyaura reaction, Sonogashira reaction or hydrogenation mediated by Wilkinson’s catalyst [84]. Other interesting examples to remove transition metals in

Total synthesis of grayanane natural products

• Nicolas Fay,
• Rémi Blieck,
• Cyrille Kouklovsky and
• Aurélien de la Torre

Beilstein J. Org. Chem. 2022, 18, 1707–1719, doi:10.3762/bjoc.18.181

• -membered triflate 71 was synthesized from diketone 26 in 5 steps and 37% overall yield. Both fragments were assembled by a Sonogashira cross-coupling, affording 72 in 72% yield. In a first attempt, TBS protection was considered on the bicylo[3.2.1]octane. However, later in the strategy, the deprotection

Formal total synthesis of macarpine via a Au(I)-catalyzed 6-endo-dig cycloisomerization strategy

• Jiayue Fu,
• Bingbing Li,
• Zefang Zhou,
• Maosheng Cheng,
• Lu Yang and
• Yongxiang Liu

Beilstein J. Org. Chem. 2022, 18, 1589–1595, doi:10.3762/bjoc.18.169

• . The convergent synthetic strategies feature the utilization of Au(I)-catalyzed cycloisomerizations of a 1,5-enyne and alkynyl ketone substrates, which were prepared by Sonogashira coupling reactions. Keywords: benzo[c]phenanthridine alkaloids; 1,5-enyne; formal total synthesis; gold catalysis

• be synthesized from silyl enol ether compound 10 via the Au(I)-catalyzed cycloisomerization reaction developed by our group [15]. The compound 10 could be constructed by the Sonogashira coupling reaction from readily prepared iodoarene 8 [12][16] and ketone 5, which could be synthesized by using

• cheap 6-bromopiperonal (2) as the starting material. To attempt the proposed synthetic strategy, ketone 5 and iodoarene 8 were prepared by following the synthetic route outlined in Scheme 4. Ketone 5 was prepared in a four-step procedure. Firstly, a Sonogashira coupling between 6-bromopiperonal (2) and

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

• HF from 1 provides 2 as an E/Z mixuture (E/Z = 1:1). We speculated that the stability of the E isomer was equal to that of the Z isomer under these conditions. To expand the scope of this reaction, we subjected product 2 to a Sonogashira cross-coupling reaction (Scheme 3). This gave a highly

• 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

• presence of KOH. In this reaction, halothane plays a key role in the construction of highly halogenated and structurally intriguing products. The tri-halogenated alkenyl ether has potential applications in organic chemistry, e.g., in Suzuki–Miyaura or Sonogashira cross-coupling reactions. Further

Palladium-catalyzed solid-state borylation of aryl halides using mechanochemistry

• Koji Kubota,
• Emiru Baba,
• Tamae Seo,
• Tatsuo Ishiyama and
• Hajime Ito

Beilstein J. Org. Chem. 2022, 18, 855–862, doi:10.3762/bjoc.18.86

• transformations. Thus far, mechanochemical palladium-catalyzed cross-coupling reactions such as Suzuki–Miyaura [34][35][36][37][38][39][40][41][42][43][44][45][46][47], Buchwald–Hartwig [48][49][50][51][52], Sonogashira [53][54][55][56], Negishi [57], Mizoroki–Heck [58][59][60], and C–S bond-forming [61

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

• , Kottayam, Kerala, 686560, India 10.3762/bjoc.18.31 Abstract Iron- and cobalt-catalyzed Sonogashira coupling reactions are becoming central areas of research in organic synthesis. Owing to their significant importance in the formation of carbon–carbon bonds, numerous green and nanoparticle protocols have

• emerged during the past decades. The non-toxic and inexpensive nature of catalysts gained much attention in recent times. In this context, their catalytic nature and activity in Sonogashira coupling reactions were well explored and compared. Most importantly, one of the highlights of this review is the

• emphasis given to green strategies. This is the first review on iron- and cobalt-catalyzed Sonogashira coupling reactions which comprehends literature up to 2020. Keywords: C–C bond formation; cobalt; green reaction; iron; nanoparticles; Sonogashira; Introduction The palladium-catalyzed cross-coupling

The PIFA-initiated oxidative cyclization of 2-(3-butenyl)quinazolin-4(3H)-ones – an efficient approach to 1-(hydroxymethyl)-2,3-dihydropyrrolo[1,2-a]quinazolin-5(1H)-ones

• Alla I. Vaskevych,
• Nataliia O. Savinchuk,
• Ruslan I. Vaskevych,
• Eduard B. Rusanov,
• Oleksandr O. Grygorenko and
• Mykhailo V. Vovk

Beilstein J. Org. Chem. 2021, 17, 2787–2794, doi:10.3762/bjoc.17.189

• ring (especially with functional groups) is annulation of the latter moiety to the quinazoline ring. Thus, a series of 1,5-disubstituted pyrroloquinazolines 3 were obtained by a three-component Sonogashira-type coupling of 2-chloro-4-substituted quinazolines 4, propargylic alcohol, and secondary amines

Visible-light-mediated copper photocatalysis for organic syntheses

• Yajing Zhang,
• Qian Wang,
• Zongsheng Yan,
• Donglai Ma and
• Yuguang Zheng

Beilstein J. Org. Chem. 2021, 17, 2520–2542, doi:10.3762/bjoc.17.169

• -catalyzed coupling reactions of terminal alkynes was published by Hwang and co-worker. In 2012, they [65] achieved a photoinitiated Sonogashira reaction using aryl halides (bromides and iodides) 20 and aryl- or alkylacetylenes 19. In control experiments, the replacement of the copper salt with palladium

• promising, scalable green process that can be used as an alternative to the conventional Sonogashira cross-coupling reactions. In 2018, Lalic and co-workers [66] extended this approach to alkyl halides and reported the photoinduced copper-catalyzed Sonogashira coupling of alkynes and alkyl iodide 21. The

• with oxime esters. Oxo-azidation of vinyl arenes. Azidation/difunctionalization of vinyl arenes. Photoinitiated copper-catalyzed Sonogashira reaction. Alkyne functionalization reactions. Alkynylation of dihydroquinoxalin-2-ones with terminal alkynes. Decarboxylative alkynylation of redox-active esters

Recent advances in the tandem annulation of 1,3-enynes to functionalized pyridine and pyrrole derivatives

• Yi Liu,
• Puying Luo,
• Yang Fu,
• Tianxin Hao,
• Xuan Liu,
• Qiuping Ding and
• Yiyuan Peng

Beilstein J. Org. Chem. 2021, 17, 2462–2476, doi:10.3762/bjoc.17.163

• ]. Then, they also reported another CuH-catalyzed coupling reaction of 1,3-enynes 54 and nitrile to prepare polysubstituted pyrroles 55 (Scheme 21) [66]. The substrates 54 could be easily prepared by Sonogashira coupling of terminal alkynes and vinyl halides. It is worth mentioning that the addition of

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

• a reliable strategy in modern organic synthesis. Palladium-catalyzed cross-coupling reactions such as Mizoroki–Heck [5][6][7][8], Suzuki–Miyaura [9][10][11], Buchwald–Hartwig [12][13], Negishi [14][15], Migita–Stille [16], Sonogashira [17], among others [18][19][20], significantly changed the design

Chemical syntheses and salient features of azulene-containing homo- and copolymers

• Vijayendra S. Shetti

Beilstein J. Org. Chem. 2021, 17, 2164–2185, doi:10.3762/bjoc.17.139

• -(n-dodecyl)azulene (16) is shown in Scheme 5A. The Sonogashira cross-coupling reaction between 4,7-dibromo-6-(n-dodecyl)azulene (13) and 4,7-diethynyl-6-(n-dodecyl)azulene (16) yielded 4,7-polyazulene 17 linked through ethynyl bridges (Scheme 5B). Similarly, the Yamamoto cross-coupling reaction

• decades. Azulene-containing homopolymers (polyazulenes) and copolymers incorporating thiophene, fluorene, benzothiadiazole, and carbazole units along the polymer backbone can be synthesized by utilizing cross-coupling strategies such as Suzuki, Sonogashira, Stille, Yamamoto, and Buchwald–Hartwig reactions

Cationic oligonucleotide derivatives and conjugates: A favorable approach for enhanced DNA and RNA targeting oligonucleotides

• Mathias B. Danielsen and
• Jesper Wengel

Beilstein J. Org. Chem. 2021, 17, 1828–1848, doi:10.3762/bjoc.17.125

• containing a stretch of four DNA nucleotides in the middle, flanked by the modifications in a ´mixmer´ design, which is important for designing gapmer ASOs [31]. Another well-established method for C-5 pyrimidine modification involves the Sonogashira cross-coupling reaction between an alkyne group and a 5

2,4-Bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridines: synthesis and photophysical properties

• Najeh Tka,
• Mohamed Adnene Hadj Ayed,
• Mourad Ben Braiek,
• Mahjoub Jabli,
• Noureddine Chaaben,
• Kamel Alimi,
• Stefan Jopp and
• Peter Langer

Beilstein J. Org. Chem. 2021, 17, 1629–1640, doi:10.3762/bjoc.17.115

• properties. Herein, starting from readily available anthranilic acid, an efficient synthesis of 2,4-bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridine derivatives was accomplished via a one-pot double Sonogashira cross-coupling method. The UV-visible absorption and emission properties of the synthesized

• catalysis. With this precursor in hand, we intended to expand the π-conjugation by introducing two arylethynyl groups by Sonogashira reactions [66][67][68][69]. For the optimization, we studied the reaction of 2 with phenylacetylene (3a) and we obtained the desired product 4a in up to 72% as best yield

• of the temperature. We found that increasing the temperature to 90 or 100 °C did not lead to any improvement (Table 1, entries 6 and 7). The best result for the Sonogashira coupling reaction between intermediate 2 and phenylacetylene (3a) was obtained using 0.6 mol % of Pd(PPh3)4, 1.2 mol % of CuI in

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

• 134 were used as starting material in the Sonogashira and Suzuki reactions. The Sonogashira−Hagihara cross-coupling led to alkynylation at position 5 of the triazole ring in the presence of CuI and Pd(PPh3)4 as catalytic system as well as K3PO4 as base in THF as solvent at 65 °C. However, the Suzuki

Double-headed nucleosides: Synthesis and applications

• Vineet Verma,
• Jyotirmoy Maity,
• Vipin K. Maikhuri,
• Ritika Sharma,
• Himal K. Ganguly and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2021, 17, 1392–1439, doi:10.3762/bjoc.17.98

• ) and 5′-O-DMTr-protected N4-(dimethylaminomethylene)-2′-deoxycytidine (134a–d) by using Sonogashira cross coupling reaction between the propargylated nucleobases, i.e., 1-propargylthymine, N4-acetyl-1-propargylcytosine, N6-benzoyl-9-propargyladenine, and N2-isobutyryl-9-propargylguanine (13a–d) and 5

• -dimethoxytrityl-5-(4-(thymin-1-yl)phenyl)ethynyl-2′-deoxyuridine (141) were synthesized via a Sonogashira cross coupling reaction between the N1-(3/4-iodophenyl)thymine derivatives 136c and 136d and 2′-deoxy-5-ethynyluridine derivative 139 (Scheme 35) [75]. All four nucleoside monomers were converted into

• ′-deoxypyrrolocytidine (146) which has adenine attached to the 6-position of the pyrrolo-2′-deoxycytidine through a methylene linker. The double-headed nucleoside 146 was synthesized through the Sonogashira coupling reaction between 5′-O-DMTr-5-iodo-2′-deoxyuridine (144) and N9-propargyladenine (45) followed by

Fritsch–Buttenberg–Wiechell rearrangement of magnesium alkylidene carbenoids leading to the formation of alkynes

• Tsutomu Kimura,
• Koto Sekiguchi,
• Akane Ando and
• Aki Imafuji

Beilstein J. Org. Chem. 2021, 17, 1352–1359, doi:10.3762/bjoc.17.94

• Sonogashira coupling reaction with organic halides. The dehydrohalogenation of gem-dihaloalkanes, vic-dihaloalkanes, and haloalkenes with strong bases is often used for the synthesis of alkynes [2]. An alternative strategy for the synthesis of alkynes is the conversion of carbonyl compounds through one-carbon

N-tert-Butanesulfinyl imines in the asymmetric synthesis of nitrogen-containing heterocycles

• Joseane A. Mendes,
• Paulo R. R. Costa,
• Miguel Yus,
• Francisco Foubelo and
• Camilla D. Buarque

Beilstein J. Org. Chem. 2021, 17, 1096–1140, doi:10.3762/bjoc.17.86

Progress in the total synthesis of inthomycins

• Bidyut Kumar Senapati

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

• Hale and Hatakeyama [57]. Recently, Burton’s group developed some efficient and tin-free total syntheses of all three inthomycins A–C ((+)-1, (+)-2, and (−)-3) using a Suzuki or Sonogashira cross-coupling of the (E)- or (Z)-alkenyl iodides 130 with the dienylboronic ester 128 as key step (Schemes 18–22

• be poor (<40%). Therefore, enyne 127 was selected as a coupling partner for the key Sonogashira reaction of alkenyl iodide (Z)-(+)-130a to construct the required (Z,Z,E)-triene for completion of the inthomycin A ((+)-1) synthesis. Fortunately, the alkenyl iodide (Z)-(+)-130a coupled smoothly with

• functional groups and isomerizable double bonds in the conjugated triene moiety. Various stereoselective cross-coupling reactions such as Stille, Suzuki, or Sonogashira or Suzuki–Miyaura have been utilized to construct the geometrically distinctive polyene systems of inthomycins A–C (1–3). The elegant work

Synthesis, crystal structures and properties of carbazole-based [6]helicenes fused with an azine ring

• Daria I. Tonkoglazova,
• Anna V. Gulevskaya,
• Konstantin A. Chistyakov and
• Olga I. Askalepova

Beilstein J. Org. Chem. 2021, 17, 11–21, doi:10.3762/bjoc.17.2

• helicenes with interesting electronic properties. Results and Discussion Synthesis In accordance with the above strategy, we first synthesized ortho-halogen alkynylazines 1a,b via the Sonogashira reaction of commercially available 2,3-dichloroquinoxaline and 2,3-dichloropyrazine with phenylacetylene using a

• catalytic systems Pd(PPh3)4/K3PO4/THF (method A) and Pd(PPh3)4/K3PO4/1,4-dioxane (method B) were less effective. 3-Alkynyl-2-carbazolylazines can also be prepared using an alternative synthetic sequence, i.e., the Suzuki–Miyaura arylation–Sonogashira reaction. It should be noted that in the case of 2,3

• /H2O catalytic system gave a mixture of the corresponding mono- and dicarbazolyl derivatives 4b (80%) and 5b (8%). The products were easily separated by column chromatography. 3-Bromo-2-carbazolylpyridine 4b was then introduced into the Sonogashira reaction with phenylacetylene giving rise to 3-alkynyl

Pentannulation of N-heterocycles by a tandem gold-catalyzed [3,3]-rearrangement/Nazarov reaction of propargyl ester derivatives: a computational study on the crucial role of the nitrogen atom

• Giovanna Zanella,
• Martina Petrović,
• Dina Scarpi,
• Ernesto G. Occhiato and
• Enrique Gómez-Bengoa

Beilstein J. Org. Chem. 2020, 16, 3059–3068, doi:10.3762/bjoc.16.255

• mixture with unknown products. Then, the iodoenesulfonamide 12 was coupled with (±)-butyn-3-ol under Sonogashira conditions [52] to afford the enynyl alcohol 13, which was treated with acetic anhydride to provide the enynyl acetate 14 in a yield of 67% over two steps. Then, we applied the typical

• was prepared via the palladium-catalyzed reduction of the corresponding phosphate 17 [54]. Iodination and Sonogashira coupling, followed by acetylation led to the formation of the desired enynyl acetate 20. This compound was treated with 5 mol % Ph3PAuCl/AgSbF6 in DCM, and after 6 h, this afforded the