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

• 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

Introducing a new 7-ring fused diindenone-dithieno[3,2-b:2',3'-d]thiophene unit as a promising component for organic semiconductor materials

• Valentin H. K. Fell,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Eman J. Hussien and
• Peter J. Skabara

Beilstein J. Org. Chem. 2022, 18, 944–955, doi:10.3762/bjoc.18.94

• [34], dibromodithienothiophene 24 is lithiated with n-butyllithium at −90 °C, and the resulting species is reacted in situ with triisopropyl borate. After aqueous workup, dithieno[3,2-b:2’,3’-d]thiophene-2,6-diylboronic acid (25) is obtained, enabling subsequent Suzuki–Miyaura cross-coupling [36

• previously by other groups [38][39], however, we here use a different protocol. Intermediates 25 or 26 were reacted in Suzuki–Miyaura couplings [36] with commercially available methyl 5-bromo-2-iodobenzoate [40], to obtain the key intermediate dimethyl 6,6’-(dithieno[3,2-b:2’,3’-d]thiophene-2,6-diyl)bis(3

• Information File 1. According to the literature [41], Aliquat 336® can be added to Suzuki–Miyaura reactions. Here, this did not improve the yield, but decreased its fluctuation from batch to batch. After sufficient amounts of intermediate 27 were isolated, attempts for ring-closure were made. Initial attempts

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

• organic materials, typically through Suzuki–Miyaura coupling [1][2][3][4][5][6][7]. The palladium-catalyzed boryl substitution of aryl halides with boron reagents, termed Miyaura–Ishiyama borylation, is an efficient method for synthesizing arylboronates with high functional group compatibility [8][9][10

• 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

Inductive heating and flow chemistry – a perfect synergy of emerging enabling technologies

• Conrad Kuhwald,
• Sibel Türkhan and
• Andreas Kirschning

Beilstein J. Org. Chem. 2022, 18, 688–706, doi:10.3762/bjoc.18.70

• flow conditions. In these reactions, the leaching of palladium was as low as 34 ppm for Suzuki–Miyaura reactions and 100 ppm for Heck reactions. Importantly, the functionalized nanoparticles could be reused several times without observing a decrease in catalytic activity. 3.2.4 Multistep processes: The

Borylated norbornadiene derivatives: Synthesis and application in Pd-catalyzed Suzuki–Miyaura coupling reactions

• Robin Schulte and
• Heiko Ihmels

Beilstein J. Org. Chem. 2022, 18, 368–373, doi:10.3762/bjoc.18.41

• -dioxaborolane was prepared and shown to be a suitable substrate for Pd-catalyzed Suzuki–Miyaura coupling reactions with selected haloarenes. It was demonstrated exemplarily that the novel monosubstituted 2-(1-naphthyl)norbornadiene, that is accessible through this route, is transformed to the corresponding

• derivatives may be metalated in a Li–halogen exchange reaction [27]. In another versatile approach, arylation and alkenylation reactions of the norbornadiene may be accomplished with a Suzuki–Miyaura coupling reaction. In this case, halogenated norbornadienes react with arylboronic acids or their esters to

• the corresponding aryl-substituted norbornadienes under optimized conditions [28][29][30][31]. To the best of our knowledge, however, no borylated norbornadiene derivatives have been employed in Suzuki–Miyaura coupling reactions so far, although this synthetic route appears to be a useful

Peptide stapling by late-stage Suzuki–Miyaura cross-coupling

• Hendrik Gruß,
• Rebecca C. Feiner,
• Ridhiwan Mseya,
• David C. Schröder,
• Michał Jewgiński,
• Kristian M. Müller,
• Rafał Latajka,
• Antoine Marion and
• Norbert Sewald

Beilstein J. Org. Chem. 2022, 18, 1–12, doi:10.3762/bjoc.18.1

• ]. Additionally, halotryptophans were incorporated in pentapeptides as building blocks for macrocyclisation by Suzuki–Miyaura cross-coupling (SMC) aiming at the preparation of bicyclic peptides [71]. Recently, intramolecular SMC has been successfully applied to side chain-to-tail cyclisation between

• stapling techniques to stabilise α-helical secondary structure motifs of peptides led to the design of modulators of protein–protein interactions, which had been considered undruggable for a long time. We disclose a novel approach towards peptide stapling utilising macrocyclisation by late-stage Suzuki

• –Miyaura cross-coupling of bromotryptophan-containing peptides of the catenin-binding domain of axin. Optimisation of the linker length in order to find a compromise between both sufficient linker rigidity and flexibility resulted in a peptide with an increased α-helicity and enhanced binding affinity to

Ligand-dependent stereoselective Suzuki–Miyaura cross-coupling reactions of β-enamido triflates

• Tomáš Chvojka,
• Athanasios Markos,
• Svatava Voltrová,
• Radek Pohl and
• Petr Beier

Beilstein J. Org. Chem. 2021, 17, 2657–2662, doi:10.3762/bjoc.17.179

• 43 Prague 2, Czech Republic 10.3762/bjoc.17.179 Abstract The stereoselective Suzuki–Miyaura cross-coupling of (Z)-β-enamido triflates is demonstrated. Depending on the nature of the ligand in the palladium catalyst, either retention or inversion of the configuration during the synthesis of β,β

• -diaryl-substituted enamides is observed. Thus, the method provides synthetic access to both isomers of the target enamides from (Z)-β-enamido triflates. Keywords: enamides; isomerization; Suzuki–Miyaura coupling; vinyl triflates; Introduction Enamides are substrates of high value in organic synthesis

Silica gel and microwave-promoted synthesis of dihydropyrrolizines and tetrahydroindolizines from enaminones

• Robin Klintworth,
• Garreth L. Morgans,
• Stefania M. Scalzullo,
• Charles B. de Koning,
• Willem A. L. van Otterlo and
• Joseph P. Michael

Beilstein J. Org. Chem. 2021, 17, 2543–2552, doi:10.3762/bjoc.17.170

• the unsubstituted pyrrole position (Scheme 5). This site was readily brominated with N-bromosuccinimide in N,N-dimethylformamide [71] to afford ethyl 7-bromo-6-phenyl-2,3-dihydro-1H-pyrrolizine-5-carboxylate (28) in 83% yield. Palladium(0)-catalyzed Suzuki–Miyaura coupling of 28 with phenylboronic

Synthesis and investigation on optical and electrochemical properties of 2,4-diaryl-9-chloro-5,6,7,8-tetrahydroacridines

• Najeh Tka,
• Mohamed Adnene Hadj Ayed,
• Mourad Ben Braiek,
• Mahjoub Jabli and
• Peter Langer

Beilstein J. Org. Chem. 2021, 17, 2450–2461, doi:10.3762/bjoc.17.162

• /bjoc.17.162 Abstract A facile synthesis of 2,4-diaryl-9-chloro-5,6,7,8-tetrahydroacridine derivatives is reported which is based on POCl3-mediated cyclodehydration followed by double Suzuki–Miyaura cross-coupling. The absorption and fluorescence properties of the obtained products were investigated and

• 3,5-dibromoanthranilic acid (1) [61] with cyclohexanone in POCl3 through an adapted reported procedure [62] (Scheme 1). With precursor 2 in hand, we intended to expand the π-conjugation of the tetrahydroacridine core by adding diversely substituted aryl groups using the Suzuki–Miyaura cross-coupling

• to 91% yield. The trifold Suzuki–Miyaura coupling product, i.e., 2,4,9-triphenyl-5,6,7,8-tetrahydroacridine, could not be prepared, even after increasing the amount of phenylboronic acid to 4 equivalents and prolonging the reaction time. Our primary screening consisted in evaluating the effect of the

Synthesis of phenanthridines via a novel photochemically-mediated cyclization and application to the synthesis of triphaeridine

• Songeziwe Ntsimango,
• Kennedy J. Ngwira,
• Moira L. Bode and
• Charles B. de Koning

Beilstein J. Org. Chem. 2021, 17, 2340–2347, doi:10.3762/bjoc.17.152

• was demonstrated to be useful for the synthesis of the natural product trisphaeridine (3) [17]. Exposure of 1-bromo-2,4,5-trimethoxybenzene (19) to Suzuki–Miyaura coupling reaction conditions with boronic acid 20 resulted in the formation of aldehyde 21 (Scheme 5). Treatment of 21 with hydroxylamine

• substituents in a range of positions. In all cases at least one methoxy substituent was positioned ortho- to the biaryl axis. The other aromatic ring had to contain an oxime ester, which would form an iminyl electron donor, as shown in Scheme 2. As illustrated substrates 13a–f were accessed using the Suzuki

• –Miyaura cross-coupling reaction of a variety of halogenated methoxybenzene-containing compounds with 2-(formylphenyl)boronic acids in generally good yields [15]. As a next step, the biaryl aldehydes 13a–f were converted into their corresponding oximes 14a–f in good yields as a mixture of (E) and (Z

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

• synthesized from tropolone (21) in five steps (Scheme 21A). The Suzuki–Miyaura coupling reaction of 2,6-dibromoazulene (125) with 2,2’-(9,9-dioctyl-9H-flourene-2,7-diyl)di(1,3,2-dioxaborolane) (103) furnished the polymer 126 in 31% yield (Scheme 21B). The other polymer 129 was obtained from 2,6-dibromoazulene

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

• ). Representative examples included indenoanthracenes 61a–c, bearing aryl groups linked to the alkyne, and indenoanthracenes 61d–f, containing tetramethylsilane groups at the terminal alkyne [46]. From commercially available 1,8-dichloroanthraquinone (62) and by using modified Suzuki–Miyaura coupling reaction

• conditions, Agarwal et al. synthesized a series of 1,8-diarylanthracene derivatives 64 in two steps (Scheme 14) [47]. First, the simple reduction of anthraquinone 62 employing the well-known reductive Zn/NH3 system and HCl provided 1,8-dichloroanthracene (63). A Suzuki–Miyaura coupling reaction in the

• published in 2018, de Koning and co-workers reported a new methodology to synthesize the benzo[a]anthracene skeleton of angucycline derivatives 146 by using a multistep strategy based on Suzuki–Miyaura, isomerization, and ring-closing metathesis reactions (Scheme 33) [67]. The commercially available 2

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

• −Miyaura cross-coupling produced a series of 5-aryl-4-ethynyl triazoles 136 in the presence of Pd(PPh3)4 as catalyst and K3PO4 as base in 1,4-dioxane as solvent at 100 °C (Scheme 39) [62]. A paper by Sekar et al. described the synthesis of polycyclic triazoles 142 through a domino alkyne insertion and C–H

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

Design, synthesis and photophysical properties of novel star-shaped truxene-based heterocycles utilizing ring-closing metathesis, Clauson–Kaas, Van Leusen and Ullmann-type reactions as key tools

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2021, 17, 1374–1384, doi:10.3762/bjoc.17.96

• be inspected from Scheme 7, our journey in this regard stem from the iodination of 2 using H5IO6/I2/H2SO4 in acetic acid–water solvent system to afford the desired triiodotruxene derivative 22 in 50% yield. Furthermore, Suzuki–Miyaura cross-coupling reaction of 22 with 4-formylphenylboronic acid (23

Synthetic accesses to biguanide compounds

• Oleksandr Grytsai,
• Cyril Ronco and
• Rachid Benhida

Beilstein J. Org. Chem. 2021, 17, 1001–1040, doi:10.3762/bjoc.17.82

• catalysts in various organic reactions [1] such as the Ullmann coupling, Suzuki coupling, Suzuki–Miyaura coupling, and the Heck reaction. Aside from being useful synthetic agents, biguanides gained particular interest from the perspective of medicinal chemistry. For the first time, the biological activity

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

• Shivani Gulati,
• Stephy Elza John and
• Nagula Shankaraiah

Beilstein J. Org. Chem. 2021, 17, 819–865, doi:10.3762/bjoc.17.71

• azepinone 22 and exemplified a modified Ugi reaction (four-component reaction). The aldehyde and acid component of the Ugi reaction was functionalized on the same biaryl ring employing a Suzuki–Miyaura coupling. The authors advocated the use of microwave as it consistently increased the yield from 49% to 82

Synthetic reactions driven by electron-donor–acceptor (EDA) complexes

• Zhonglie Yang,
• Yutong Liu,
• Kun Cao,
• Xiaobin Zhang,
• Hezhong Jiang and
• Jiahong Li

Beilstein J. Org. Chem. 2021, 17, 771–799, doi:10.3762/bjoc.17.67

• -metal catalysts, such as in the Suzuki–Miyaura and Heck coupling reactions. Methodologies for forming different C–C bonds have recently been developed in the field of single-electron chemistry [63][64][65]. Considering that EDA-complex-initiated free-radical reactions are carried out under mild

Total synthesis of pyrrolo[2,3-c]quinoline alkaloid: trigonoine B

• Takashi Nishiyama,
• Erina Hamada,
• Daishi Ishii,
• Yuuto Kihara,
• Nanase Choshi,
• Natsumi Nakanishi,
• Mari Murakami,
• Kimiko Taninaka,
• Noriyuki Hatae and
• Tominari Choshi

Beilstein J. Org. Chem. 2021, 17, 730–736, doi:10.3762/bjoc.17.62

• -azahexatriene system. Lastly, it was proposed that the carbodiimide 10 could be derived from urea 11. Therefore, we investigated the electrocyclization of a pyrrol-3-ylbenzene containing a carbodiimide moiety. First, 2-(pyrrol-3-yl)aniline 14 was synthesized by a Suzuki–Miyaura coupling reaction of 2

• -iodo-5-methoxyaniline (24), was synthesized according to the procedure previously reported by Wetzel and co-workers [31]. The Suzuki–Miyaura coupling of 2-iodoaniline derivative 24 and pyrrole-3-boronic acid pinacol ester 13 was carried out in the presence of Pd(OAc)2 and SPhos, followed by the

Helicene synthesis by Brønsted acid-catalyzed cycloaromatization in HFIP [(CF₃)₂CHOH]

• Takeshi Fujita,
• Noriaki Shoji,
• Nao Yoshikawa and
• Junji Ichikawa

Beilstein J. Org. Chem. 2021, 17, 396–403, doi:10.3762/bjoc.17.35

• bisacetal precursors, which were readily prepared through C–C bond formation by Suzuki–Miyaura coupling. This cyclization was efficiently realized by a catalytic amount of trifluoromethanesulfonic acid (TfOH) in a cation-stabilizing solvent, 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP), which readily allowed

• central aromatic ring (Ar1) (Scheme 3, route b). The teraryl structures were constructed by the formation of two C–C bonds via tandem Suzuki–Miyaura coupling of two terminal (Ar2) and central (Ar1) arenes. It is noted that dihalogenated arenes were adopted as components for the central aromatic ring (Ar1

• , and heterohelicenes. Results and Discussion Carbohelicenes such as [5]helicene (1a) and [6]helicene (1b) were synthesized via Suzuki–Miyaura coupling of readily available dihalogenated arenes 2 with phenylboronic acid ester 3 bearing a (1,3-dioxolan-2-yl)methyl group [29], followed by triflic acid

Progress in the total synthesis of inthomycins

• Bidyut Kumar Senapati

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

• between vinyl bromide (Z,Z)-(+)-145a and (E)-vinylstannane 24 [43] proceeded without significant isomerization to give (4Z,6Z,8E)-triene (+)-146a, a subunit of inthomycin A ((+)-1). Meanwhile, the Suzuki–Miyaura coupling of vinylboronate (Z,E)-(+)-145b with the known (E)-oxazole iodide 48 [43] was

• 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

• 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

Naphthalonitriles featuring efficient emission in solution and in the solid state

• Sidharth Thulaseedharan Nair Sailaja,
• Iván Maisuls,
• Jutta Kösters,
• Alexander Hepp,
• Andreas Faust,
• Jens Voskuhl and
• Cristian A. Strassert

Beilstein J. Org. Chem. 2020, 16, 2960–2970, doi:10.3762/bjoc.16.246

• exhibit weak emission in the inner cell, and ACQgens show weak emission in the outer cell [44]. Results and Discussion Synthesis and structural characterization In this contribution, six different p-phenyl-2,3-disubstituted-6,7-diphenylnaphthalenes with variable moieties were synthesized by the Suzuki

• –Miyaura coupling reaction starting from 6,7-dibromo-2,3-dicyanonaphthalene, which was prepared according to the literature [45] (Scheme 2). The compounds with the substituents R = H [46] and t-Bu [47] are already known and were herein investigated for comparative purpose. The standard reaction conditions

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

• Suzuki–Miyaura cross-coupling reaction of bromosumanene 82 under microwave reaction conditions. Whereas another route involves the Ni-catalyzed aryl–aryl homo-coupling between the two molecules of iodosumanene 79 [51][52]. Moreover, the bissumanenyl 92, which is thought to be chiral because of the two

• , very few reports could be found for selective functionalization at the peripheral carbons because of difficulties arose during their synthesis. In this regard, Toda et al. in 2017 have successfully synthesized 2,3,5,6,8,9-hexaarylsumanene derivatives 95a–h utilizing a Suzuki–Miyaura cross-coupling