Synthesis and properties of 6-alkynyl-5-aryluracils

• Ruben Manuel Figueira de Abreu,
• Till Brockmann,
• Alexander Villinger,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 898–911, doi:10.3762/bjoc.20.80

• (5k, 5l, 5r). However, this effect seems to be neutralized when using an electron-rich arylboronic acid (5m). Lower yields are obtained when an acceptor group is present on the arylalkyne (5p, 5q). This leads to the suggestion that an electron-donor group activates and an electron-withdrawing group

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 synthesis of fluoranthenes 19–27 via Suzuki coupling followed by C–H bond functionalization The reaction of 1,8-dibromonaphthalene (0.286 g, 1 mmol), arylboronic acid (1.5 mmol) and KOPiv (0.420 g, 3 mmol) in the presence of PdCl(C3H5)(dppb) (30.5 mg, 0.05 mmol) at 150 °C during 16 h in

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

• of two substituted arylboronic acids, followed by N-methylation, and final ring-closure via Bischler–Napieralski conditions [45][47][48]. These steps provided chelerythrine variants C1–C4, with structural variability stemming from the initial substituted tetralone (R1/R2) and/or the arylboronic acid

Palladium-catalyzed enantioselective three-component synthesis of α-arylglycine derivatives from glyoxylic acid, sulfonamides and aryltrifluoroborates

• Bastian Jakob,
• Nico Schneider,
• Luca Gengenbach and
• Georg Manolikakes

Beilstein J. Org. Chem. 2023, 19, 719–726, doi:10.3762/bjoc.19.52

• imine species provide a very flexible approach to the arylglycine scaffold [2][9]. The Petasis borono-Mannich reaction constitutes a prominent example for such an imine-based multicomponent reaction (Scheme 1a). The reaction of glyoxylic acid, an amine component and an arylboronic acid offers a highly

• situ generation of reactive imine species, we have disclosed iron- and bismuth-catalyzed three-component reactions for the synthesis of α-arylglycines [14][15][16], in which the arylboronic acid could be replaced with an electron-rich (hetero)arene as nucleophile. In parallel, we have developed

• . However, depending on the nature/substitution pattern of the arylboronic acid, some of the arylglycine products could only be obtained in very low enantioselectivities. This can be attributed to a fast, uncatalyzed racemic background reaction of the boronic acids, in particular for electron-rich or

Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

• Austin Pounder,
• Eric Neufeld,
• Peter Myler and
• William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38

• azaspirotricyclic alkenes 176 using arylboronic acids 177 (Scheme 32) [79]. This reaction proceeded well with a variety of ester substituents on the nitrogens of the azaspirotricyclic alkenes. The authors proposed this reaction proceeds first through a transmetalation of the arylboronic acid 177a with the Rh(I

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

• mill; borylation; cross-coupling; mechanochemistry; solid-state reaction; Introduction Arylboronic acid and its derivatives are indispensable reagents in modern synthetic chemistry because they have been frequently used for the preparation of many bioactive molecules, natural products, and functional

• , solvent-free palladium-catalyzed borylation process applicable for a wide range of aryl halides would greatly improve the practicality of the desired arylboronic acid derivatives. Nechaev et al. reported the first solvent-free protocol for the palladium-catalyzed Miyaura–Ishiyama borylation of aryl

Substituent effect on TADF properties of 2-modified 4,6-bis(3,6-di-tert-butyl-9-carbazolyl)-5-methylpyrimidines

• Irina Fiodorova,
• Tomas Serevičius,
• Rokas Skaisgiris,
• Saulius Juršėnas and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 497–507, doi:10.3762/bjoc.18.52

• wt % PMMA films of carbazole–pyrimidine TADF compounds in oxygen-free conditions. Synthesis of 4,6-bis(3,6-di-tert-butyl-9H-carbazol-9-yl)-5-methyl-2-substituted pyrimidines 1–6. Reagents and conditions: i – Raney Ni, MeOH, 90 °C, 2 h; ii – arylboronic acid (1.3 equiv), Pd(PPh3)4 (5 mol %), Cs2CO3 (2

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

• Suzuki–Miyaura reaction [35]. It should be noted that the inverse coupling, i.e., of 2-bromonorbornadiene with arylboronic acid derivatives is also a reasonable and already tested alternative route, that gives very good yields in the case of higher substituted norbornadiene products [28][29]. However

• , the approach presented herein avoids the use of the significantly more expensive reagents such as the arylboronic acid derivatives and the (t-Bu)3P ligand. To add to that, the latter is also highly air sensitive and thus requires special handling, but it is essential for a reasonably efficient Pd

• coupling, i.e., of the 2-bromonorbornadiene with arylboronic acid derivatives is also a reasonable and already tested alternative route, but the approach presented herein avoids the use of the usually more expensive arylboronic acid derivatives. In any case, with both complementary methods at hand the

AlBr₃-Promoted stereoselective anti-hydroarylation of the acetylene bond in 3-arylpropynenitriles by electron-rich arenes: synthesis of 3,3-diarylpropenenitriles

• Yelizaveta Gorbunova,
• Dmitry S. Ryabukhin and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2021, 17, 2663–2667, doi:10.3762/bjoc.17.180

• way for the synthesis of compounds 2. These compounds can be alternatively obtained by a Pd-catalyzed Heck reaction of 3-arylpropenenitriles with iodoarenes [23] or by a Cu-catalyzed hydroarylation of 3-arylpropynenitriles with arylboronic acid [24][25]. There is one example of use of dicyanoacetylene

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

• base led to the identification of Pd(PPh3)4 (10 mol %), arylboronic acid (1 equiv), K3PO4 (2 equiv) in THF/H2O 1:1 as ideal conditions providing enamides 2aa and 3aa in a 93:7 ratio in 90% 19F NMR yield (Table S1 in Supporting Information File 1). The optimized conditions were applied to the scope

• gel. A moderate loss of stereochemistry was observed only in cases of bulky ortho-substitution of either arylboronic acid or vinyl triflate (2ad, 2da, and 2dd). Alkylboronic acids were found to be unreactive even after prolonged reaction time (1a with n-hexylboronic acid, 60 h, rt). Next, conditions

• for the formation of isomeric products were optimized. Screening the reaction conditions identified Pd(dppf)Cl2 (10 mol %), arylboronic acid (1.2 equiv), KF (2 equiv) in THF/H2O 15:1 at 50 °C as a system affording the best obtained ratio and yield in favor to product 3aa (Table S2 in Supporting

Recent advances in organocatalytic asymmetric aza-Michael reactions of amines and amides

• Pratibha Sharma,
• Raakhi Gupta and
• Raj K. Bansal

Beilstein J. Org. Chem. 2021, 17, 2585–2610, doi:10.3762/bjoc.17.173

• catalytic systems, namely arylboronic acid alone, its dual combination with chiral thiourea and integrated catalyst having boronic acid functionality in the chiral thiourea molecule. The dual combination of arylboronic acid with chiral thiourea was found as effective as arylboronic acid alone for the

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

• equivalents of K3PO4 in toluene at 100 °C for 4 hours. With our optimized conditions in hand, we examined the scope of the reaction of 2 with other arylboronic acids 3b–g (Scheme 2). As expected, we found that electron-donating groups located in the arylboronic acid improved the yield. The cross-coupling of 2

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

• . Experimental For general experimental procedures, please consult Supporting Information File 1. Suzuki coupling: general procedure To a deoxygenated 0.25 M solution of arylboronic acid (1.2 equiv) in DME stirring under argon was added aryl bromide (1.0 equiv), Pd(PPh3)4 (10 mol %) and deoxygenated 2 M aqueous

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

• (hetero)arylboronic acid 111 was reported. The use of a catalytic amount of CuCl and MeOLi as base in CH3CN as solvent was recognized as the optimized conditions. This strategy provided a new procedure for the one-pot synthesis of fully decorated 1,2,3-triazole derivatives 112 in good to excellent yield

• formed, which trough the CuAAC path generates the C5-cuprate triazole intermediate 115. The oxidative addition of arylboronic acid to the copper center forms the intermediate 116. The reductive elimination occurs to give the corresponding triazole 112 and to reform the copper catalyst for the next run

Recent advances in palladium-catalysed asymmetric 1,4–additions of arylboronic acids to conjugated enones and chromones

• Jan Bartáček,
• Jan Svoboda,
• Martin Kocúrik,
• Jaroslav Pochobradský,
• Alexander Čegan,
• Miloš Sedlák and
• Jiří Váňa

Beilstein J. Org. Chem. 2021, 17, 1048–1085, doi:10.3762/bjoc.17.84

• given combination of enone and arylboronic acid. Keywords: asymmetric reaction; boronic acid; conjugated enones; chromones; enantioselective catalysis; Michael addition; Pd complexes; Introduction The asymmetric 1,4-addition of arylboronic acids to conjugated cyclic enones and chromones is a very

• enantioselectivities were low to moderate (up to 60% ee; Table 34) [14]. Another option to obtain the linear product is the ring opening of the addition product of the arylboronic acid to the dihydropyran-2-one derivative (Scheme 23) [14]. The Minnaard group next focused on the increase of the reactivity of ortho

• substrates as well as for 2-unsubstituted chromones [17][18][19][21][22][23][24]. On the other hand, there is only one example of the usage of a rhodium-based catalyst for the addition of arylboronic acid to 3-substituted enones. The olefino-oxazoline ligand L18 has been used for the rhodium-catalysed

Palladium-catalyzed regio- and stereoselective synthesis of aryl and 3-indolyl-substituted 4-methylene-3,4-dihydroisoquinolin-1(2H)-ones

• Valeria Nori,
• Antonio Arcadi,
• Armando Carlone,
• Fabio Marinelli and
• Marco Chiarini

Beilstein J. Org. Chem. 2020, 16, 1084–1091, doi:10.3762/bjoc.16.95

• situ-generated arylpalladium iodide complex to the triple bond to give an (E)-vinylpalladium intermediate, which underwent cross-coupling with an arylboronic acid leading to the final product by reductive elimination, with the regeneration of the Pd(0) catalyst. Finally, we envisaged that the above

Synthesis and anticancer activity of bis(2-arylimidazo[1,2-a]pyridin-3-yl) selenides and diselenides: the copper-catalyzed tandem C–H selenation of 2-arylimidazo[1,2-a]pyridine with selenium

• Mio Matsumura,
• Tsutomu Takahashi,
• Hikari Yamauchi,
• Shunsuke Sakuma,
• Yukako Hayashi,
• Tadashi Hyodo,
• Tohru Obata,
• Kentaro Yamaguchi,
• Yasuyuki Fujiwara and
• Shuji Yasuike

Beilstein J. Org. Chem. 2020, 16, 1075–1083, doi:10.3762/bjoc.16.94

• -phenanthroline catalytic system [28]. Guo, Han, et al. reported a method that used a Cu(OAc)2/1,10-phenanthroline catalyst in the presence of KOH (2 equiv); this method replaced the aryl source from an arylboronic acid with an aryl iodide [30]. Zhou et al. reported the reactions of imidazopyridines, Se powder

Pd-catalyzed asymmetric Suzuki–Miyaura coupling reactions for the synthesis of chiral biaryl compounds with a large steric substituent at the 2-position

• Yongsu Li,
• Bendu Pan,
• Xuefeng He,
• Wang Xia,
• Yaqi Zhang,
• Hao Liang,
• Chitreddy V. Subba Reddy,
• Rihui Cao and
• Liqin Qiu

Beilstein J. Org. Chem. 2020, 16, 966–973, doi:10.3762/bjoc.16.85

• product [13][39][42][57][65] along with the Pd···O interaction [13][64] between carbonyl and palladium. The experimental results also show that the substituent of the arylboronic acid has an obvious effect on the reaction: the yield and ee value of the product decrease with the increase of the steric

• %), arylboronic acid (0.4 mmol, 2.0 equiv), K3PO4 (0.6 mmol, 3.0 equiv) and 2 mL of dry THF. S-Phos was used as ligand for the preparation of racemic products and all the reactions were carried out at 50 °C for 72 h. The completion of the reaction was checked by TLC. After completion of the reaction, the reaction

• with phenylboronic acid derivatives also resulted in poor enantioselectivities of the products (see Supporting Information File 1, Scheme S1, 3u, 60% yield, 11% ee; 3v, 99% yield, 0% ee). This further demonstrates the importance of the steric hindrance and rigidity from the other substrate arylboronic

Asymmetric synthesis of CF₂-functionalized aziridines by combined strong Brønsted acid catalysis

• Xing-Fa Tan,
• Fa-Guang Zhang and
• Jun-An Ma

Beilstein J. Org. Chem. 2020, 16, 638–644, doi:10.3762/bjoc.16.60

• attributed to the increased Brønsted acidity when the strong electron-withdrawing trifluoromethyl group was placed on the benzene ring of the arylboronic acid. Removing the boronic acid from the reaction system leads to a dramatic decrease in both yield and enantiocontrol (Table 1, entry 16). The challenge

Architecture and synthesis of P,N-heterocyclic phosphine ligands

• Wisdom A. Munzeiwa,
• Bernard Omondi and
• Vincent O. Nyamori

Beilstein J. Org. Chem. 2020, 16, 362–383, doi:10.3762/bjoc.16.35

• quinazolinones 89. Subsequent chlorination of the quinazolinone resulted in the formation of 4-chloroquinazoline intermediates 90. The subsequent Pd-catalyzed coupling of 90 and arylboronic acid 91 gave the methoxy intermediates 92 in reasonable yields. The demethylation of the 2-(2-pyridyl)methoxy intermediate

Recent advances in transition-metal-catalyzed incorporation of fluorine-containing groups

• Xiaowei Li,
• Xiaolin Shi,
• Xiangqian Li and
• Dayong Shi

Beilstein J. Org. Chem. 2019, 15, 2213–2270, doi:10.3762/bjoc.15.218

• for product formation and a successful outcome of the reaction. In the same year, the Ritter group [52] reported a Pd-catalyzed fluorination of arylboronic acid derivatives via a Pd(II)/Pd(III) cycle (Scheme 15). A single-electron-transfer (SET) mechanism involving a well-defined Pd(III) intermediate

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

• the formal synthesis of triptolide (Figure 2, route N) [43]. This synthesis highlighted the palladium-catalyzed asymmetric addition of arylboronic acid 37 to 3-methylcyclohex-2-en-1-one (38) to form the C-10 quaternary chiral center, and a subsequent Claisen rearrangement and an aldol reaction to

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

Robust perfluorophenylboronic acid-catalyzed stereoselective synthesis of 2,3-unsaturated O-, C-, N- and S-linked glycosides

• Madhu Babu Tatina,
• Xia Mengxin,
• Rao Peilin and
• Zaher M. A. Judeh

Beilstein J. Org. Chem. 2019, 15, 1275–1280, doi:10.3762/bjoc.15.125

• -acetyl-D-glucal 4a and O- and S-nucleophiles. Perfluorophenylboronic-acid-catalyzed reaction between 3,4-di-O-acetyl-L-rhamnal (6a) and O- and S-nucleophiles. Plausible perfluorophenylboronic acid-catalyzed activation of glycal 1a. Optimization of the arylboronic acid-catalyzed reaction of 3,4,6-tri-O

Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis

• Gwendal Grelier,
• Benjamin Darses and
• Philippe Dauban

Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128

• non-symmetrical diaryl-λ3-iodanes raises the issue of regioselectivity. This strategy has been then extended to the preparation of alkyne-substituted alkylidenefluorenes 53 by replacing the arylboronic acid with a second equivalent of the terminal alkyne and performing the reaction at 35 °C (Scheme 18