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

• and phthalazine derivatives of type 4 containing an alkylsulfanyl functional group at the 4 position, that is based on the Pd-catalyzed coupling reaction between mercaptanes and 4-bromolactams (Scheme 1, route A) [30]. In continuing our efforts on the functionalization of phthalazinones and

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

Starazo triple switches – synthesis of unsymmetrical 1,3,5-tris(arylazo)benzenes

• Andreas H. Heindl and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2020, 16, 22–31, doi:10.3762/bjoc.16.4

• Baeyer–Mills reactions and the other based on Pd-catalyzed coupling reactions of arylhydrazides and aryl halides, followed by oxidation, were investigated. The Pd-catalyzed route efficiently led to the target compounds, unsymmetrical tris(arylazo)benzenes. These triple switches were preliminarily

• example of such compounds are 1,3,5-tris(arylazo)benzenes – ‘starazos’ – introduced by Cho and co-workers in 2004 (Figure 1) [10]. Despite their successful synthesis, using Pd-catalyzed coupling reactions of aryl halides and arylhydrazides [11] followed by Cu(I)-mediated oxidation, the photochemical

• tris(arylazo)benzenes 3 relied on Pd-catalyzed coupling reactions and Cu(I) oxidation, as presented by Cho and co-workers (Scheme 2) [10]. This route offers the advantage that the preparation of a wide variety of N-(tert-butoxycarbonyl)phenylhydrazides has already been reported [17][18][19

Palladium-catalyzed Sonogashira coupling reactions in γ-valerolactone-based ionic liquids

• László Orha,
• József M. Tukacs,
• László Kollár and
• László T. Mika

Beilstein J. Org. Chem. 2019, 15, 2907–2913, doi:10.3762/bjoc.15.284

• synthesis of a wide range of functionalized organic molecules from laboratory to industrial scale [1][2][3]. Among these tools, the Pd-catalyzed coupling reactions have received substantial attention, due to the mild operation conditions, excellent functional group tolerance and chemoselectivity as well as

Synthesis of 2H-furo[2,3-c]pyrazole ring systems through silver(I) ion-mediated ring-closure reaction

• Vaida Milišiūnaitė,
• Rūta Paulavičiūtė,
• Eglė Arbačiauskienė,
• Vytas Martynaitis,
• Wolfgang Holzer and
• Algirdas Šačkus

Beilstein J. Org. Chem. 2019, 15, 679–684, doi:10.3762/bjoc.15.62

• -furo[2,3-c]pyrazoles starting from commercially available 1-phenylpyrazol-3-ol. Iodination of the latter compound with iodine in DMF smoothly afforded 1-phenyl-4-iodopyrazol-3-ol, which can undergo a Pd-catalyzed coupling with terminal alkynes to give the corresponding 4-alkynyl-3-hydroxy-1-phenyl-1H

• -catalyzed coupling of 4-iodo-1-phenyl-1H-pyrazol-3-ol with ethyne derivatives. The structures of the obtained target compounds were unequivocally confirmed by detailed 1H, 13C and 15N NMR spectroscopic experiments, HRMS and a single-crystal X-ray diffraction analyses. This silver(I)-mediated 5-endo-dig

• and efficient procedure to access the 2H-furo[2,3-c]pyrazole ring system was developed by employing the silver(I) ion-mediated ring-closure reaction of 4-alkynyl-3-hydroxy-1-phenyl-1H-pyrazoles as a key step. The required intermediate hydroxyalkynyl substrates for this reaction were prepared by a Pd

One-pot preparation of 4-aryl-3-bromocoumarins from 4-aryl-2-propynoic acids with diaryliodonium salts, TBAB, and Na₂S₂O₈

• Teppei Sasaki,
• Katsuhiko Moriyama and
• Hideo Togo

Beilstein J. Org. Chem. 2018, 14, 345–353, doi:10.3762/bjoc.14.22

• -phenylcoumarin (6Aa) in 62 and 51% yields, respectively. The Pd-catalyzed coupling reactions of 3-bromo-4-phenylcoumarin (3Aa) with 4-methylstyrene/K2CO3/PdCl2(Ph3P)2, with phenylacetylene/PdCl2(Ph3P)2/Et3N and with PhB(OH)2/K2CO3/PdCl2(Ph3P)2 provided the corresponding C–C bonded coumarin derivatives 7Aa, 8Aa

Synthesis of substituted Z-styrenes by Hiyama-type coupling of oxasilacycloalkenes: application to the synthesis of a 1-benzoxocane

• James R. Vyvyan,
• Courtney A. Engles,
• Scott L. Bray,
• Erik D. Wold,
• Christopher L. Porter and
• Mikhail O. Konev

Beilstein J. Org. Chem. 2017, 13, 2122–2127, doi:10.3762/bjoc.13.209

• ; palladium; silicon; Introduction The development of transition metal-catalyzed cross-coupling technologies over the last four decades revolutionized the synthetic chemistry. Indeed, the importance of Pd-catalyzed coupling was recognized with the 2010 Nobel Prize awarded to Heck, Negishi and Suzuki [1][2

Preparation of imidazo[1,2-a]-N-heterocyclic derivatives with gem-difluorinated side chains

• Layal Hariss,
• Kamal Bou Hadir,
• Mirvat El-Masri,
• Thierry Roisnel,
• René Grée and
• Ali Hachem

Beilstein J. Org. Chem. 2017, 13, 2115–2121, doi:10.3762/bjoc.13.208

• as an attractive precursor to increase the molecular diversity around this scaffold. In order to explore this possibility, we performed two Suzuki–Miyaura reactions, as representative examples of Pd-catalyzed coupling processes (Table 3). They gave the target molecules 8 and 9 in 46% and 53% yields

• prepared in fair yields by the reaction of gem-difluoroenones with aminopyridines, -pyrimidines and -pyridazines. Condensed heterocycles of this type play an important role as key core structures of various bioactive compounds. Further, starting with a chloroimidazopyridazine derivative, Pd-catalyzed

• coupling reactions as well as nucleophilic substitutions have been performed successfully in order to increase the molecular diversity. Keywords: aerobic oxidative coupling; imidazo[1,2-a]-N-heterocycles; gem-difluoroalkyl derivatives; propargylic fluorides; Introduction Nitrogen-containing heterocyclic

Pd- and Cu-catalyzed approaches in the syntheses of new cholane aminoanthraquinone pincer-like ligands

• Nikolay V. Lukashev,
• Gennadii A. Grabovyi,
• Dmitry A. Erzunov,
• Alexey V. Kazantsev,
• Gennadij V. Latyshev,
• Alexei D. Averin and
• Irina P. Beletskaya.

Beilstein J. Org. Chem. 2017, 13, 564–570, doi:10.3762/bjoc.13.55

• . Though 5a was not observed in the reaction with 1,3-diiodobenzene, a good yield was obtained with 1,3-dibromobenzene. In fact, the Pd-catalyzed coupling was more efficient [43] than Ullmann-type chemistry (61% from 1,3-dibromobenzene vs 40% from 1,3-diiodobenzene). Since the anthraquinone skeleton is

Highly bulky and stable geometry-constrained iminopyridines: Synthesis, structure and application in Pd-catalyzed Suzuki coupling of aryl chlorides

• Yi Lai,
• Zhijian Zong,
• Yujie Tang,
• Weimin Mo,
• Nan Sun,
• Baoxiang Hu,
• Zhenlu Shen,
• Liqun Jin,
• Wen-hua Sun and
• Xinquan Hu

Beilstein J. Org. Chem. 2017, 13, 213–221, doi:10.3762/bjoc.13.24

• been omitted for clarity. Preparation of the bulky iminopyridyl–palladium complexes. Pd-catalyzed coupling of chlorobenzene and 4-tolylboronic acid using Pd1–Pd5 as the catalyst.a Selected bond lengths [Å] and angles [°] for complexes Pd2. The optimization of conditions for Pd-catalyzed coupling

• reactions between chlorobenzene and phenylboronic acid a. Pd-catalyzed coupling between various aryl chlorides and arylboronic acids.a Crystal data and structure refinement for Pd2. Supporting Information Supporting Information File 50: NMR spectra of palladium complexes and products. Acknowledgements

Symmetry-based approach to oligostilbenoids: Rapid entry to viniferifuran, shoreaphenol, malibatol A, and diptoindonesin G

• Youngeun Jung,
• Dileep Kumar Singh and
• Ikyon Kim

Beilstein J. Org. Chem. 2016, 12, 2689–2693, doi:10.3762/bjoc.12.266

• . Keywords: anticancer agent; iodocyclization; natural product; oligostilbenoids; Pd-catalyzed coupling; Introduction Oligostilbenoids constitute a family of natural products with various biological functions (Figure 1). Monomeric stilbene units are interconnected in a number of ways to lead to complex

Catalytic asymmetric formal synthesis of beraprost

• Yusuke Kobayashi,
• Ryuta Kuramoto and
• Yoshiji Takemoto

Beilstein J. Org. Chem. 2015, 11, 2654–2660, doi:10.3762/bjoc.11.285

• % yield (dr > 10:1) via the method established in Scheme 3. After derivatization to acetal 22 in 2 steps, we then turned our attention to the introduction of the C4 ester substituents. Amongst various different conditions investigated – including Pd-catalyzed coupling reactions – a halogen-lithium

Synthesis and chemosensing properties of cinnoline-containing poly(arylene ethynylene)s

• Natalia A. Danilkina,
• Petr S. Vlasov,
• Semen M. Vodianik,
• Andrey A. Kruchinin,
• Yuri G. Vlasov and
• Irina A. Balova

Beilstein J. Org. Chem. 2015, 11, 373–384, doi:10.3762/bjoc.11.43

• -catalyzed coupling typically requires heating to 80–100 °C [45], we first tried heating in DMF at 80 °C over 24 h in the presence of diisopropanolamine (DIPA) as a base (Table 2, entry 1). Under those conditions the reaction yielded an unexpected 4-methylcinnoline 7a that could be explained in terms of

• reported [41][51], the double Sonogashira coupling for dibromocinnolines has not been investigated. To optimize the coupling conditions, several test experiments were carried out using the 4,6-dibromo-3-butylcinnoline (4a, Table 2). Taking into account that the substitution of a bromine atom in Pd

Palladium-catalyzed 2,5-diheteroarylation of 2,5-dibromothiophene derivatives

• Fatma Belkessam,
• Aidene Mohand,
• Jean-François Soulé,
• Abdelhamid Elias and
• Henri Doucet

Beilstein J. Org. Chem. 2014, 10, 2912–2919, doi:10.3762/bjoc.10.309

• et al. reported the Pd-catalyzed coupling of 2,5-dibromothiophene with 3-methoxythiophene to afford the corresponding terthiophene in 29% yield [37]. From 2,5-diiodothiophene and benzoxazole, using 5 mol % Pd(phen)2(PF6)2 catalyst, the 2,5-diheteroarylated thiophene was obtained in 89% yield by Murai

Practical synthesis of aryl-2-methyl-3-butyn-2-ols from aryl bromides via conventional and decarboxylative copper-free Sonogashira coupling reactions

• Andrea Caporale,
• Stefano Tartaggia,
• Andrea Castellin and
• Ottorino De Lucchi

Beilstein J. Org. Chem. 2014, 10, 384–393, doi:10.3762/bjoc.10.36

• acid has been reported by Lee, in which the Pd-catalyzed coupling of propiolic acid with an aryl iodide is followed by the addition of the Cu-catalyst, which promotes the protodecarboxylation of the arylpropiolic acid intermediate to the desired alkyne in good yields [70]. Acetylenic compounds and

• . Therefore, the Pd-catalyzed coupling reaction of 4 or a propiolic acid derivative with 3-bromoaniline, in order to approach the synthesis of 3-aminophenylacetylene without the use of copper, would be highly desiderable [76]. Although many examples of copper-free Sonogashira reactions between aryl halides

• the acetylenic proton of 5 was necessary. Analogously to acetylene [80][81], the protection of propiolic acid with acetone was carried out in presence of an excess of KOH (6.0 equiv) at room temperature (Scheme 2). The screening of the optimal palladium catalyst for the Pd-catalyzed coupling reaction

Synthesis of enones, pyrazolines and pyrrolines with gem-difluoroalkyl side chains

• Assaad Nasr El Dine,
• Ali Khalaf,
• Danielle Grée,
• Olivier Tasseau,
• Fares Fares,
• Nada Jaber,
• Philippe Lesot,
• Ali Hachem and
• René Grée

Beilstein J. Org. Chem. 2013, 9, 1943–1948, doi:10.3762/bjoc.9.230

• successfully developed for these sequential reactions. By carrying out various types of Pd-catalyzed coupling reactions for compounds with a p-bromophenyl substituent a route to focused chemical libraries was demonstrated. Keywords: 19F/1H HOESY; gem-difluoroalkyl derivatives; organo-fluorine compounds

• -difluoro alkyl side chain. One-pot synthesis of pyrrolines with a gem-difluoro side chain. Pd-catalyzed coupling reactions towards chemical libraries of pyrazolines with a gem-difluoro side chain. Pd-catalyzed coupling reactions towards chemical libraries of pyrrolines with a gem-difluoro side chain

• ) in the presence of methylhydrazine (Scheme 4) the pyrazolines 4a–4e were obtained after 3–7 h in excellent yields (82–92%, Table 2). This very short and efficient synthesis of pyrazolines 4 can be related to another excellent one-pot reaction with 3-components where the first step is a Pd-catalyzed

Palladium-catalyzed C–N and C–O bond formation of N-substituted 4-bromo-7-azaindoles with amides, amines, amino acid esters and phenols

• Rajendra Surasani,
• Dipak Kalita,
• A. V. Dhanunjaya Rao and
• K. B. Chandrasekhar

Beilstein J. Org. Chem. 2012, 8, 2004–2018, doi:10.3762/bjoc.8.227

• -mediated coupling of amides, amines, amino acid esters and phenols with N-protected 7-azaindole derivatives for one of our medicinally important drug-development programs. We herein report on Pd-catalyzed coupling reactions of N-protected 4-bromo-7-azaindoles with amides, amines, amino acid esters and

The chemistry of bisallenes

• Henning Hopf and
• Georgios Markopoulos

Beilstein J. Org. Chem. 2012, 8, 1936–1998, doi:10.3762/bjoc.8.225

Koch–Haaf reaction of adamantanols in an acid-tolerant hastelloy-made microreactor

• Takahide Fukuyama,
• Yu Mukai and
• Ilhyong Ryu

Beilstein J. Org. Chem. 2011, 7, 1288–1293, doi:10.3762/bjoc.7.149

• practical organic syntheses using flow microreactors, and we have reported thus far examples of Pd-catalyzed coupling reactions [11][12][13], radical reactions [14][15][16], and photoreactions [17][18][19][20][21]. Carbonylation reactions are a powerful tool for the introduction of carbon monoxide into

Asymmetric Au-catalyzed cycloisomerization of 1,6-enynes: An entry to bicyclo[4.1.0]heptene

• Alexandre Pradal,
• Chung-Meng Chao,
• Patrick Y. Toullec and
• Véronique Michelet

Beilstein J. Org. Chem. 2011, 7, 1021–1029, doi:10.3762/bjoc.7.116

• studies. Synthesis of 1,6-enynes We prepared various oxygen-tethered 1,6-enynes according to classic methodologies employing a Williamson alkylation reaction and/or a Sonogashira cross-coupling [60][61] (Scheme 2 and Scheme 3). The known enyne 5 [62][63] was engaged in Pd-catalyzed coupling in the

Synthesis, reactivity and biological activity of 5-alkoxymethyluracil analogues

• Lucie Brulikova and
• Jan Hlavac

Beilstein J. Org. Chem. 2011, 7, 678–698, doi:10.3762/bjoc.7.80

• of 3',5'-dihydroxyl groups with the TBDMS group followed by a Pd-catalyzed coupling reaction with vinyl acetate to give the protected 5-vinyluridine 129 in 68% yield. Oxidation with OsO4 with subsequent acetylation with acetic anhydride in pyridine gave nucleoside 131. The target phosphoramidite 134

Synthesis of chiral mono(N-heterocyclic carbene) palladium and gold complexes with a 1,1'-biphenyl scaffold and their applications in catalysis

• Lian-jun Liu,
• Feijun Wang,
• Wenfeng Wang,
• Mei-xin Zhao and
• Min Shi

Beilstein J. Org. Chem. 2011, 7, 555–564, doi:10.3762/bjoc.7.64

• coupling reactions and a Au-catalyzed asymmetric reaction, respectively. Suzuki–Miyaura and Heck–Mizoroki coupling reactions catalyzed by NHC–Pd(II) complex The Pd-catalyzed coupling reaction is one of the most powerful methods for the formation of carbon–carbon bonds in organic synthesis [60][61][62][63

• reported NHC–Au complexes [57][58][59]. The NHC–metal complex [(NHC)Pd(allyl)I] complex 7 and NHC–Au(I) complex (S)-6a, are air and moisture stable both in the solid state and in solution, and can be used as catalysts. Therefore, the catalytic activities of these complexes were investigated in Pd-catalyzed

Conjugated polymers containing diketopyrrolopyrrole units in the main chain

• Bernd Tieke,
• A. Raman Rabindranath,
• Kai Zhang and
• Yu Zhu

Beilstein J. Org. Chem. 2010, 6, 830–845, doi:10.3762/bjoc.6.92

• monomer as well as conventional Pd-catalyzed coupling of M-1 and the 3,6-diphenyl(4,4´-bis(pinacolato)boron ester) derivative of DPP. The polymer exhibits a bordeaux-red colour in solution with absorption maxima of about 525 nm, and a purple luminescence with a maximum around 630 nm with a Stokes-shift of

• spectroelectrochemical plots of P-25 and P-26 as thin films on ITO glass. Scan rate: 100 mVs−1; potential vs. ferrocene (from [50]). Synthesis of DPP monomers. Pd-catalyzed coupling reactions for preparation of DPP-containing polymers. Thiophenyl-DPP-based polymers. List of diphenylDPP-based polymers prepared upon

Pd/C-mediated synthesis of α-pyrone fused with a five-membered nitrogen heteroaryl ring: A new route to pyrano[4,3-c]pyrazol-4(1H)-ones

• Dhilli Rao Gorja,
• Venkateswara Rao Batchu,
• Ashok Ettam and
• Manojit Pal

Beilstein J. Org. Chem. 2009, 5, No. 64, doi:10.3762/bjoc.5.64

• conditions on the Pd-catalyzed coupling of 5-iodo-1-methyl-1H-pyrazole-4-carboxylic acid (1) with 1-hexyne (2a).a Pd/C-mediated synthesis of 6-substituted pyrano[4,3-c]pyrazol-4(1H)-onesa (3). Supporting Information Supporting Information File 84: General procedure for the preparation of 3 and spectral data

Shape- persistent macrocycle with intraannular alkyl groups: some structural limits of discotic liquid crystals with an inverted structure

• Sigurd Höger,
• Jill Weber,
• Andreas Leppert and
• Volker Enkelmann

Beilstein J. Org. Chem. 2008, 4, No. 1, doi:10.1186/1860-5397-4-1

• compared to macrocycle 1. 3,5-Diiodo-4-methylbenzene (2) was treated with trimethylsilyl(TMS)acetylene under standard Hagihara-Sonogashira coupling conditions and subsequently deprotected with K2CO3 in MeOH/THF. As expected, the Pd-catalyzed coupling reaction runs under milder conditions and with higher

• PAH substituents (Scheme 3). Pd-catalyzed coupling of the diiodo compound 14 with the mono protected bisacetylene 20, deprotection of the acetylenes with TBAF and subsequent coupling with an excess of the diiodo compound 5c gave the diiodide 23. Hagihara-Sonogashira coupling of 23 with an excess of