Structure–property relationships in dicyanopyrazinoquinoxalines and their hydrogen-bonding-capable dihydropyrazinoquinoxalinedione derivatives

• Tural N. Akhmedov,
• Ajeet Kumar,
• Daken J. Starkenburg,
• Kyle J. Chesney,
• Khalil A. Abboud,
• Novruz G. Akhmedov,
• Jiangeng Xue and
• Ronald K. Castellano

Beilstein J. Org. Chem. 2024, 20, 1037–1052, doi:10.3762/bjoc.20.92

• functionality as well as Buchwald–Hartwig amination involving aryl halides. Thermal studies Thermal stabilities of DCPQs 1a–6a and DPQDs 1b–7b were evaluated using thermogravimetric analysis (TGA; Figure 2 and Table S4 in Supporting Information File 1). The thermal stability of the DCPQs is attributed to their

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

• dibenzodiazepinones in good yields (up to 45%; 2 steps) and much milder conditions using copper as the catalyst. The synthetic utility of this novel strategy was showcased by demonstrating a formal synthesis for the antipsychotic drug clozapine and to an anticancer triazole–DBDAP hybrid. Keywords: Buchwald–Hartwig

• review in 2018 focused on a variety of routes to these compounds [8]. The well-known Buchwald–Hartwig (B–H) and Chan–Lam (C–L) reactions have proven to be highly useful procedures that allow the step-economical synthesis of diverse biologically relevant heterocycles through C–N bond formation [9]. These

The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads

• Liyuan Cao,
• Xi Liu,
• Xue Zhang,
• Jianzhang Zhao,
• Fabiao Yu and
• Yan Wan

Beilstein J. Org. Chem. 2023, 19, 1028–1046, doi:10.3762/bjoc.19.79

• chromophores, which are coupled through a Buchwald–Hartwig coupling reaction (another NI-PTZ paper) [39]. The oxidation of the PTZ unit was readily performed by treatment with H2O2 as oxidant (Scheme 1). All compounds were obtained with satisfactory yields and the molecular structures were fully characterized

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

• synthesised via a copper-catalysed Ullman-type coupling or a palladium-catalysed Buchwald–Hartwig amination (Scheme 9). Performing the rearrangement at high temperatures resulted in the undesirable formation of acridine byproducts 44. Cleaner reaction profiles could be obtained at a lower temperature (100 °C

• categorised according to the major or final catalytic step employed to form the 7-membered heterocycle as several synthetic methods use multiple catalytic steps. 3.1 Buchwald–Hartwig amination, etherification and thioetherification The Buchwald–Hartwig reaction gives access to arylamines, -ethers and

• -pyridobenzazepines 60b via cyclisation of 2,2'-dihalostilbene analogue 58 through a Pd-catalysed double Buchwald–Hartwig amination. The stilbene analogues 58 were prepared by a Wittig reaction with reported yields of the desired Z-isomer around 55%. The amination step was performed on a series of primary alkylamines

Ionic multiresonant thermally activated delayed fluorescence emitters for light emitting electrochemical cells

• Merve Karaman,
• Abhishek Kumar Gupta,
• Subeesh Madayanad Suresh,
• Tomas Matulaitis,
• Lorenzo Mardegan,
• Daniel Tordera,
• Henk J. Bolink,
• Sen Wu,
• Stuart Warriner,
• Ifor D. Samuel and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2022, 18, 1311–1321, doi:10.3762/bjoc.18.136

• synthetic strategy, which itself was synthesized from Br-DiKTa [28] following a Buchwald–Hartwig coupling. Details of the synthesis are found in Supporting Information File 1. The identity and purity of the molecules were verified using a combination of 1H and 13C NMR spectroscopy, high resolution mass

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

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

• -9H-carbazol-9-yl)-5-methyl-2-methylthiopyrimidine (tCbz-mPYR) as a starting material for the synthesis of 2-substituted pyrimidine emitters (Scheme 1). Compound tCbz-mPYR was synthesized by using the palladium-catalyzed Buchwald–Hartwig amination reaction of 4,6-dichloro-5-methyl-2-methylpyrimidine

Comparative study of thermally activated delayed fluorescent properties of donor–acceptor and donor–acceptor–donor architectures based on phenoxazine and dibenzo[a,j]phenazine

• Saika Izumi,
• Prasannamani Govindharaj,
• Anna Drewniak,
• Paola Zimmermann Crocomo,
• Satoshi Minakata,
• Leonardo Evaristo de Sousa,
• Piotr de Silva,
• Przemyslaw Data and
• Youhei Takeda

Beilstein J. Org. Chem. 2022, 18, 459–468, doi:10.3762/bjoc.18.48

• mono-functionalized compound DBPHZ-OTf, the target compound 1 was successfully synthesized through a Pd-catalyzed Buchwald–Hartwig amination with phenoxazine (POZ) in a good yield as red-brown solid (Scheme 1). The D–A–D counterpart POZ-DBPHZ was synthesized according to the previously reported process

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

• effective electron delocalization along the C2 axis (C2v symmetry) passing through 2,6-positions of azulene [23][24][25]. The first chemical synthesis of such polyazulene called poly[2,6-aminoazulene] 31 was reported by Luh and co-workers [26] in 2017 and achieved by using the Buchwald–Hartwig reaction

• protocol (Scheme 7). The synthesis of the key building blocks 2-aminoazulene (24), 2-amino-6-bromoazulene (26), and its corresponding carbamate, tert-butyl N-(6-bromoazulen-2-yl)carbamate (27), used in their synthesis is presented in Scheme 7A. The carbamate 27 was subjected to a Buchwald–Hartwig 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

Catalyzed and uncatalyzed procedures for the syntheses of isomeric covalent multi-indolyl hetero non-metallides: an account

• Ranadeep Talukdar

Beilstein J. Org. Chem. 2021, 17, 2102–2122, doi:10.3762/bjoc.17.137

• ]. Hongtao and co-workers reported the synthesis of tetrakisindole species 13 through the coupling of aniline (12) and indole-2-boronic acid pinacol ester 11 using the Buchwald–Hartwig method (Scheme 3a) [42]. In a similar fashion, Han reported the syntheses of the symmetric and unsymmetric triaryl

• indolyl amines through Buchwald–Hartwig cross coupling. Synthesis of 3,3’-bis(indolyl) ethers. C–H silylation of indoles. n-BuLi-mediated syntheses of bis(indol-3-yl)silanes. Acid-catalyzed syntheses of bis(indol-3-yl)silanes and mechanisms. B(C6F5)3 and Al(C6F5)3-catalyzed syntheses of bis(indol-3-yl

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

• substitution [17][18][19][20][21] of berberrubine (1b) have been performed, whereas the direct O-arylation of berberrubine has not been accomplished, yet, most likely because the substrate is not fully compatible with the usual conditions of the corresponding Ullmann or Buchwald–Hartwig coupling reactions

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

• synthesis of the 2,3-dihydroquinolin-4-one moiety of trigonoine B (1) by cycloamination of 22c (Scheme 4). The Buchwald–Hartwig amination of 22c was conducted in the presence of t-BuONa, BINAP, and Pd2(dba)3·CHCl3; however, the desired tetrahydroquinoline 23 was not obtained and only 22c was recovered. We

Amino- and polyaminophthalazin-1(2H)-ones: synthesis, coordination properties, and biological activity

• Zbigniew Malinowski,
• Emilia Fornal,
• Agata Sumara,
• Renata Kontek,
• Karol Bukowski,
• Beata Pasternak,
• Dariusz Sroczyński,
• Joachim Kusz,
• Magdalena Małecka and
• Monika Nowak

Beilstein J. Org. Chem. 2021, 17, 558–568, doi:10.3762/bjoc.17.50

• quinazolinones [30][31] and taking into consideration the biological importance of aminophthalazine derivatives, we decided to apply the methodology based on the palladium-catalyzed C–N-bond formation (Buchwald–Hartwig-type reaction) as a convenient and effective approach for the synthesis of the new

• course of the reaction and in several cases resulted in the formation of 2-methylphthalazin-1(2H)-one, i.e., the debromination product of bromophthalazinone 3a. The commonly adopted view on the mechanism of the Pd-mediated C–N-bond formation (Buchwald–Hartwig-type coupling) [37][38][39][40] assumes that

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

• ethers of 3,6-diacetylcarbazole with p-benzoquinone (Scheme 1B) [49], the double Buchwald–Hartwig amination of 4,4'-biphenanthrene derivatives (Scheme 1C) [45] and a enantioselective Fischer indolization–oxidation protocol (Scheme 1D) [43]. Each method is not without drawbacks such as hardly available

Synthesis and characterization of S,N-heterotetracenes

• Astrid Vogt,
• Florian Henne,
• Christoph Wetzel,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2020, 16, 2636–2644, doi:10.3762/bjoc.16.214

• nitrogen heteroatoms were synthesized in multistep synthetic routes. A Buchwald–Hartwig amination of brominated precursors, thermolysis of azide precursors, and a Cadogan reaction of nitro-substituted precursors were successfully applied to eventually build-up pyrrole rings to stable and soluble fused

• replacement of sulfur by nitrogen atoms in the tetra- and hexacyclic systems leads to a red-shift in absorption, a decrease in oxidation potential and energy gap. On the other hand, the replacement of a thiophene ring by benzene leads to the opposite effects. Keywords: Buchwald–Hartwig amination; Cadogan

• -heteroacenes, dimeric thieno[3,2-b]pyrrole [8] and trimeric dithieno[3,2-b:2’,3’-d]pyrrole (DTP) [9], are long known but still frequently used as building block for organic electronic materials [10]. By application of Pd-catalyzed Buchwald–Hartwig amination/cyclization reactions of brominated thiophene-based

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

• arylation of the nucleophilic nitrogen atom, known as the Ullmann [6][7] reaction, and its modification by Chan and Lam [8] are favored due to the several advantages they offer versus the Pd counterpart (i.e., the Buchwald–Hartwig reaction) such as the lower cost and lower toxicity of the metal as well as

Synthesis and characterization of bis(4-amino-2-bromo-6-methoxy)azobenzene derivatives

• David Martínez-López,
• Amirhossein Babalhavaeji,
• Diego Sampedro and
• G. Andrew Woolley

Beilstein J. Org. Chem. 2019, 15, 3000–3008, doi:10.3762/bjoc.15.296

• were then replaced by amino substituents using a Buchwald–Hartwig coupling [20]. Since calculations predicted that 5- and 6-membered rings would have similar effects on the positions of the absorption maxima, we opted to use 6-membered rings, specifically a morpholino substituent and a piperazino

Palladium-catalyzed synthesis and nucleotide pyrophosphatase inhibition of benzo[4,5]furo[3,2-b]indoles

• Hoang Huy Do,
• Saif Ullah,
• Alexander Villinger,
• Joanna Lecka,
• Jean Sévigny,
• Peter Ehlers,
• Jamshed Iqbal and
• Peter Langer

Beilstein J. Org. Chem. 2019, 15, 2830–2839, doi:10.3762/bjoc.15.276

• , Québec, QC, G1V 4G2, Canada Leibniz-Institut für Katalyse an der Universität Rostock e.V., Albert Einstein Str. 29a, 18059 Rostock, Germany 10.3762/bjoc.15.276 Abstract A two-step palladium-catalyzed procedure based on Suzuki–Miyaura cross coupling, followed by a double Buchwald–Hartwig reaction, allows

• results were rationalized based on docking studies. Keywords: Buchwald–Hartwig reaction; cyclization; N-heterocycles; palladium; Suzuki–Miyaura reaction; Introduction Furoindoles and their derivatives have received a lot of attention based on their versatile pharmaceutical activities. Furoindols were

• studied double Buchwald–Hartwig reactions as the key step for the synthesis of heterocycles. For example, the cyclization of 2,2’-dibromobiaryls with amines allows for a convenient synthesis of carbazole derivatives [22][23][24][25][26][27][28][29][30]. Recently, we reported the synthesis of

Plasma membrane imaging with a fluorescent benzothiadiazole derivative

• Pedro H. P. R. Carvalho,
• Jose R. Correa,
• Karen L. R. Paiva,
• Daniel F. S. Machado,
• Jackson D. Scholten and
• Brenno A. D. Neto

Beilstein J. Org. Chem. 2019, 15, 2644–2654, doi:10.3762/bjoc.15.257

•  1. The new fluorescent structure is accessible in a two-step procedure from the commercially available 4-bromo-2,1,3-benzothiadiazole (BTD-Br) and 4-aminopyridine (4AP), as we have recently described [41]. The Buchwald–Hartwig amination protocol afforded the fluorescent BTD-4AP in 80% yield after

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

Remarkable effect of alkynyl substituents on the fluorescence properties of a BN-phenanthrene

• Alberto Abengózar,
• David Sucunza,
• Patricia García-García and
• Juan J. Vaquero

Beilstein J. Org. Chem. 2019, 15, 1257–1261, doi:10.3762/bjoc.15.122

• -phenanthrene 1a [23]. Thus, an initial Buchwald–Hartwig amination between 2-bromo-5-chlorostyrene and 3-butenylamine was the initial step. This coupling was performed at 70 °C, as a higher yield was obtained at this temperature (71% at 80 °C, 24 h vs 82% at 70 °C, 48 h). Substrate 2 was then cyclized with

• reactions of 1b, under conditions optimized for a related BN-benzo[c]phenanthrene [30]. Gratifyingly, Suzuki coupling and Buchwald–Hartwig amination yielded the corresponding aryl- and amino-substituted BN-phenanthrenes 1c and 1d in good yields (Scheme 2). Moreover, Sonogashira couplings efficiently proceed

Assembly of fully substituted triazolochromenes via a novel multicomponent reaction or mechanochemical synthesis

• Robby Vroemans,
• Yenthel Verhaegen,
• My Tran Thi Dieu and
• Wim Dehaen

Beilstein J. Org. Chem. 2018, 14, 2689–2697, doi:10.3762/bjoc.14.246

• -known biologically active analogs (Scheme 5) [3]. Pd-catalyzed reactions were effected on bromotriazolochromene 5e. The piperazin-1-ylchromenes have been identified to be potent inhibitors at the 5-HT1A receptor and at the 5-HT transporter [45][46]. Thus, Buchwald–Hartwig amination of 1-phenylpiperazine

Rational design of boron-dipyrromethene (BODIPY) reporter dyes for cucurbit[7]uril

• Mohammad A. Alnajjar,
• Jürgen Bartelmeß,
• Robert Hein,
• Pichandi Ashokkumar,
• Mohamed Nilam,
• Werner M. Nau,
• Knut Rurack and
• Andreas Hennig

Beilstein J. Org. Chem. 2018, 14, 1961–1971, doi:10.3762/bjoc.14.171

• the aminomethyladamantane derivative 5, a route via a bromophenyl-BODIPY BDP-Br followed by a Buchwald–Hartwig coupling was performed. For the latter, a previously published Pd/XPhos containing catalytic system was successfully utilized (route D) [39]. Spectroscopic characterization of dyes To ensure

The first Pd-catalyzed Buchwald–Hartwig aminations at C-2 or C-4 in the estrone series

• Ildikó Bacsa,
• Dávid Szemerédi,
• János Wölfling,
• Gyula Schneider,
• Lilla Fekete and
• Erzsébet Mernyák

Beilstein J. Org. Chem. 2018, 14, 998–1003, doi:10.3762/bjoc.14.85

• with benzophenone imine and subsequent hydrogenolysis. Keywords: aminoestrones; Buchwald–Hartwig amination; 13α-estrone; functionalization; microwave assisted reactions; Introduction Aminoestrones are of particular interest thanks to their diverse biological applications [1][2][3][4]. There exist

• application of a Pd-catalyzed Buchwald–Hartwig amination. In recent years, extensive efforts have been made on the Pd(0)-catalyzed amination of aryl halides or triflates in order to achieve the efficient synthesis of substituted anilines [6][7][8][9]. Buchwald et al. stated that the Pd source is determining

• in the amination step [9]. They also found that X-Phos is an outstanding ligand with increased activity and stability compared to those based on BINAP [10]. There are a number of literature methods with respect to microwave-assisted Buchwald–Hartwig couplings [11][12][13]. Many publications have