Synthesis of 9-arylalkynyl- and 9-aryl-substituted benzo[b]quinolizinium derivatives by Palladium-mediated cross-coupling reactions

• Siva Sankar Murthy Bandaru,
• Darinka Dzubiel,
• Heiko Ihmels,
• Mohebodin Karbasiyoun,
• Mohamed M. A. Mahmoud and
• Carola Schulzke

Beilstein J. Org. Chem. 2018, 14, 1871–1884, doi:10.3762/bjoc.14.161

• -Arylbenzo[b]quinolizinium derivatives were prepared with base-free Suzuki–Miyaura coupling reactions between benzo[b]quinolizinium-9-trifluoroborate and selected benzenediazonium salts. In addition, the Sonogashira coupling reaction between 9-iodobenzo[b]quinolizinium and the arylalkyne derivatives yielded

• ]quinolizinium derivatives have to be optimized [34][35]. Accordingly, we extended our studies to improve the conditions of the Suzuki–Miyaura coupling towards biaryl-type benzo[b]quinolizinium derivatives 1a–d (Figure 1), namely to apply the alternative base-free Suzuki–Miyaura coupling reaction [39][40][41][42

• ] between the benzo[b]quinolizinium-9-trifluoroborate (3b) and aryldiazonium salts. We focused our attention on derivatives 1a–d because in these cases a direct comparison with the already reported synthesis with a Suzuki–Miyaura reaction is possible. As we are particularly interested in benzo[b

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

• 59 in moderate to good yields. Nevertheless, a two-fold excess of the iodonium triflate is needed to secure a good conversion, a point that limits again the atom-economy of the overall process. Similarly, the group of Liu has described the double Suzuki–Miyaura coupling reaction of cyclic diaryl-λ3

• , gives access to various iodoaminated intermediates that can be subsequently engaged in palladium-catalyzed Suzuki–Miyaura, Sonogashira, or Mizoroki–Heck cross-coupling reactions. Various aryl, alkenyl, or alkynyl substituents can thus be introduced in good to very good yields. When compared to the

• auto-amination process enables to address the issue of chemoselectivity in some cases. For example, the Suzuki–Miyaura coupling allows for introducing a pyridinyl or a furyl ring that are not compatible with the rhodium-catalyzed oxidizing amination reactions. In a similar manner, the group of

Recent applications of chiral calixarenes in asymmetric catalysis

• Mustafa Durmaz,
• Erkan Halay and
• Selahattin Bozkurt

Beilstein J. Org. Chem. 2018, 14, 1389–1412, doi:10.3762/bjoc.14.117

• reaction in the following order: phase-transfer catalysis, Henry reaction, Suzuki–Miyaura cross-coupling and Tsuji–Trost allylic substitution, hydrogenation, Michael addition, aldol and multicomponent Biginelli reactions, epoxidation, Meerwein−Ponndorf−Verley reduction, aza-Diels−Alder and epoxide ring

• . The low enantioselectivities obtained were mainly attributed to the high flexibility of catalytic amino groups of N,O-type enantiomers. Suzuki–Miyaura cross–coupling and Tsuji–Trost allylic substitution reaction Manoury et al. described the synthesis of ferrocene-bearing enantiomerically pure

• calixarenes and their catalytic performances in the asymmetric Suzuki–Miyaura coupling and Tsuji–Trost allylic alkylation reactions (Scheme 7) [42]. Calix[4]arene mono and dithiophosphines 24–26 were efficiently synthesized from p-tert-butylcalix[4]arene by a one pot Mitsunobu alkylation using

[3 + 2]-Cycloaddition reaction of sydnones with alkynes

• Veronika Hladíková,
• Jiří Váňa and
• Jiří Hanusek

Beilstein J. Org. Chem. 2018, 14, 1317–1348, doi:10.3762/bjoc.14.113

• group can be easily substituted by an aryl group using a Suzuki–Miyaura cross-coupling reaction. In those cases when a trimethylsilyl group (R4) is also present, it can be removed by TBAF-mediated protodesilylation to give a 1,4,5-trisubstituted pyrazole. It is worth noting that the parent 4,4,5,5

• , alkyl or alkenyl group via Suzuki coupling reaction with boronic acids to give otherwise rarely available 1,4,5-trisubstituted pyrazoles [119]. The second limitation is that the CuSAC reaction proceeds only with terminal alkynes. The latter fact clearly indicates some kind of participation of the

Atom-economical group-transfer reactions with hypervalent iodine compounds

• Andreas Boelke,
• Peter Finkbeiner and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2018, 14, 1263–1280, doi:10.3762/bjoc.14.108

• –boron bond formation gives one equivalent of arylboronic ester 4 and an iodoarene 2 through a metal-free boron arylation. Subsequent cross coupling under Suzuki conditions affords symmetrical biphenyls 3’ in good yields. Due to the temporary introduction and cleavage of the boron moiety the formal atom

• iodoarenes 32. These species smoothly underwent subsequent Suzuki–Miyaura, Sonogashira and Mirozoki–Heck couplings. The respective arylated, alkynylated and alkenylated products 33a–d were obtained in high yields with excellent stereoselectivity. Due to the intramolecular pathway of the first step, high AE

A selective removal of the secondary hydroxy group from ortho-dithioacetal-substituted diarylmethanols

• Anna Czarnecka,
• Emilia Kowalska,
• Agnieszka Bodzioch,
• Joanna Skalik,
• Marek Koprowski,
• Krzysztof Owsianik and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2018, 14, 1229–1237, doi:10.3762/bjoc.14.105

• reactions (e.g., Suzuki–Miyaura, Stille, Kumada, Hiyama or Negishi couplings) play a key role in the preparation of diarylmethanes. However, the reactions involving sulfur-containing moieties have not been reported yet (Scheme 1) [1]. It is noteworthy that under certain conditions, the Pd-catalyzed cross

Rhodium-catalyzed C–H functionalization of heteroarenes using indoleBX hypervalent iodine reagents

• Erwann Grenet,
• Ashis Das,
• Paola Caramenti and
• Jérôme Waser

Beilstein J. Org. Chem. 2018, 14, 1208–1214, doi:10.3762/bjoc.14.102

• ), which ends up on the pyridinone ring. As alternative, a Suzuki–Miyaura coupling between 3-halogenoindoles and (2-methoxypyridyl)boronic acids followed by a deprotection of the methoxy group [7][8] or transition-metal-catalyzed annulation methods [9] have also been reported. In contrast, several

One hundred years of benzotropone chemistry

• Arif Dastan,
• Haydar Kilic and
• Nurullah Saracoglu

Beilstein J. Org. Chem. 2018, 14, 1120–1180, doi:10.3762/bjoc.14.98

Recent advances in synthetic approaches for medicinal chemistry of C-nucleosides

• Kartik Temburnikar and
• Katherine L. Seley-Radtke

Beilstein J. Org. Chem. 2018, 14, 772–785, doi:10.3762/bjoc.14.65

• for the stability of 37 and to facilitate functional group interconversions as shown in Figure 12A [53]. In order to obtain carbocyclic C-nucleosides that resemble canonical nucleosides, Maier and coworkers synthesized a stable enol triflate (46, Figure 13A), which then enables Suzuki coupling and a

• modular synthesis of carbocyclic C-nucleosides [53]. The boronic acids/boronates (inset, Figure 13) of several (hetero)aryls were conducive to Suzuki coupling with the best result obtained when the C2', C3' and C5'–OHs were protected with TIPS and pivaloyl groups, respectively [53]. The cross-coupling

• separable mixture of diastereomers (2:1). In addition, optically pure cyclopentanone (−)-45 was obtained by converting the cyclopentane 43 to camphanates (51, Figure 13B) followed by separation of the diastereomers [53]. Subsequent synthesis of the enol triflate (−)-46 (Figure 13B), Suzuki coupling and

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• these Pd-catalytic micelles was also achieved while catalyzing reactions involving less reactive or sterically hindered species. Handa et al. described a self-assembled TPGS-750M micelle (shown in Scheme 1), that allowed for copper-catalyzed Suzuki–Myaura coupling of aryl iodides (Scheme 2) [70]. When

• were assembled from hydrophilic poly(ethylene oxide) (PEO) and hexa-p-phenylene, providing a platform for Suzuki reactions with the hydrophobic core acting as a suitable pocket for apolar aromatic guests [71][72]. With such a platform, full conversion was achieved at room temperature in water. Almost

• Pd catalyst together with a PAA (poly(acrylic acid)) based polymer self-assembled in water [32]. The catalytic activity of the nanostructures was compared to the results achieved with the small molecule analogues of the pincer Pd complex, in a Suzuki–Miyaura coupling. When the reaction of vinyl

Heterogeneous Pd catalysts as emulsifiers in Pickering emulsions for integrated multistep synthesis in flow chemistry

• Katharina Hiebler,
• Georg J. Lichtenegger,
• Manuel C. Maier,
• Eun Sung Park,
• Renie Gonzales-Groom,
• Bernard P. Binks and
• Heidrun Gruber-Woelfler

Beilstein J. Org. Chem. 2018, 14, 648–658, doi:10.3762/bjoc.14.52

• development of heterogeneous Pd catalysts that are ready to be used in combination with biocatalysts for catalytic cascade synthesis of active pharmaceutical ingredients (APIs). In particular, we focus on the application of the catalytic systems for Suzuki–Miyaura cross-coupling reactions, which is the key

• minimal leaching behaviour is demonstrated with various Suzuki–Miyaura cross-coupling reactions in batch as well as in continuous flow employing the so-called “plug & play reactor”. Finally, we demonstrate the use of these particles as the sole emulsifier of oil–water emulsions for a range of oils

• , Pd-catalysed C–C cross-coupling reactions have become indispensable in many modern synthetic protocols both in the laboratory and on an industrial scale. A highly important representative of this class of transformation is the Suzuki–Miyaura reaction [5][6], involving the coupling of aryl halides

Synthesis and stability of strongly acidic benzamide derivatives

• Frederik Diness,
• Niels J. Bjerrum and
• Mikael Begtrup

Beilstein J. Org. Chem. 2018, 14, 523–530, doi:10.3762/bjoc.14.38

• , reversed-phase chromatography was chosen to simplify the purifications. The N-triflylbenzamide group also proved stable to cross-coupling reaction conditions, as exemplified by a palladium-catalyzed Suzuki–Miyaura reaction of the 4-bromo-substituted derivative 9d (Scheme 3). The corresponding N,N’-bis

One-pot sequential synthesis of tetrasubstituted thiophenes via sulfur ylide-like intermediates

• Jun Ki Kim,
• Hwan Jung Lim,
• Kyung Chae Jeong and
• Seong Jun Park

Beilstein J. Org. Chem. 2018, 14, 243–252, doi:10.3762/bjoc.14.16

• methods [44][45][46][47][48][49]. In general, Pd-catalyzed Suzuki–Miyaura cross-coupling reactions are the most popular synthetic strategy for aryl–aryl bond-forming reactions [50][51][52]. However, it has been reported that the Suzuki cross-coupling of nitrogen- and sulfur-containing heterocycles is more

5-Aminopyrazole as precursor in design and synthesis of fused pyrazoloazines

• Ranjana Aggarwal and
• Suresh Kumar

Beilstein J. Org. Chem. 2018, 14, 203–242, doi:10.3762/bjoc.14.15

• corresponding N1-alkyl-3-iodopyrazolo[3,4-d]pyrimidine derivatives 225. The iodinated pyrazolo[3,4-d]pyrimidines were alkylated at C3 with boronic acids (R2-B(OH)2) using Suzuki coupling conditions to give 4-amino-N1,C3-dialkylpyrazolo[3,4-d]pyrimidines 226 (Scheme 61). Synthesis of pyrazolo[3,4-b]pyrazines

Synthesis and spectroscopic properties of β-meso directly linked porphyrin–corrole hybrid compounds

• Baris Temelli and
• Hilal Kalkan

Beilstein J. Org. Chem. 2018, 14, 187–193, doi:10.3762/bjoc.14.13

• -porphyrin, β-corrole-linked hybrid structure described a Suzuki–Miyaura cross-coupling reaction between a β-borylated corrole and meso-bromoporphyrins (Scheme 1D) [37]. Recently, we have successfully synthesized meso–meso and β-meso-linked imine-bridged porphyrin–corrole conjugates and investigated

Fluorescent nucleobase analogues for base–base FRET in nucleic acids: synthesis, photophysics and applications

• Mattias Bood,
• Sangamesh Sarangamath,
• Moa S. Wranne,
• Morten Grøtli and
• L. Marcus Wilhelmsson

Beilstein J. Org. Chem. 2018, 14, 114–129, doi:10.3762/bjoc.14.7

• a more straightforward and versatile synthetic route. The Stille coupling was changed to a Suzuki–Miyaura coupling and the cyclization was performed directly starting from the free aniline nitrogen, as we found that Boc protection was required only for cyclization when using DBU and DABCO. To faster

• first construct a common intermediate that could be used for various Suzuki-coupling partners similar to what we previously reported [55], by first protecting 6-chloro-7-iodo-7-deazapurine with tert-butyldimethylsilyloxymethyl (TBDMSOM) in 86% yield over two steps (44, Scheme 10). A Miyaura-type

• borylation afforded the common intermediate 45 in 91% yield and Suzuki coupling was then achieved efficiently for both 2-amino-3-iodopyridine as well as 2-iodo-4-nitroaniline in (46) 95% and (47) 86% yield, respectively. The activation of the exocyclic amine was achieved by using AcCl which provided a more

Reactivity of bromoselenophenes in palladium-catalyzed direct arylations

• Aymen Skhiri,
• Ridha Ben Salem,
• Jean-François Soulé and
• Henri Doucet

Beilstein J. Org. Chem. 2017, 13, 2862–2868, doi:10.3762/bjoc.13.278

• ][5][6][7][8][9], Suzuki [10][11][12][13][14][15][16][17][18][19], or Kumada [20] couplings [21] (Scheme 1a and b). However, all these procedures require the preparation of an organometallic or a boron derivative of one of the coupling partners, and provide an organometallic salt (MX) as waste. In

Ring-size-selective construction of fluorine-containing carbocycles via intramolecular iodoarylation of 1,1-difluoro-1-alkenes

• Takeshi Fujita,
• Ryo Kinoshita,
• Tsuyoshi Takanohashi,
• Naoto Suzuki and
• Junji Ichikawa

Beilstein J. Org. Chem. 2017, 13, 2682–2689, doi:10.3762/bjoc.13.266

• Takeshi Fujita Ryo Kinoshita Tsuyoshi Takanohashi Naoto Suzuki Junji Ichikawa Division of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan 10.3762/bjoc.13.266 Abstract 1,1-Difluoro-1-alkenes bearing a biaryl-2-yl group effectively underwent

Structure–property relationships and third-order nonlinearities in diketopyrrolopyrrole based D–π–A–π–D molecules

• Jan Podlesný,
• Lenka Dokládalová,
• Oldřich Pytela,
• Adam Urbanec,
• Milan Klikar,
• Numan Almonasy,
• Tomáš Mikysek,
• Jaroslav Jedryka,
• Iwan V. Kityk and
• Filip Bureš

Beilstein J. Org. Chem. 2017, 13, 2374–2384, doi:10.3762/bjoc.13.235

• 7 using a larger excess of NBS resulted in its decomposition. According to the current literature reports [18][19][27], DPP derivative 8 undergoes smooth cross-coupling reactions. Hence, we have utilized twofold Suzuki–Miyaura and Migita–Stille reactions leading to chromophores 1a–3a and 4a

• , respectively. Commercially available 4-(N,N-dimethylamino)phenylboronic, 4-methoxyphenylboronic, and 2-thienylboronic acids completed with tributyl(5-methoxythiophen-2-yl)stannane, prepared from 2-methoxythiophene [33], were used. Chromophore 4a was also attempted by Suzuki–Miyaura reaction using the

• in modular way prepared by Suzuki–Miyaura, Migita–Stille, and Sonogashira cross-coupling reactions. The chromophores differ in the π-system extension as well as in the peripheral substitution. The thermal stability of 1–5 is mostly affected by the presence of acetylene linkers, 1,4-phenylene and 2,5

Synthesis and application of trifluoroethoxy-substituted phthalocyanines and subphthalocyanines

• Satoru Mori and
• Norio Shibata

Beilstein J. Org. Chem. 2017, 13, 2273–2296, doi:10.3762/bjoc.13.224

• . Furthermore, the same structural dimer of TFEO-Pc and tert-butyl-substituted phthalocyanine 7b was synthesized by the Suzuki coupling reaction. These dimers show a new absorption peak in the longer wavelength region than the Q band which is not observed in the monomer. This suggests intramolecular electronic

Novel approach to hydroxy-group-containing porous organic polymers from bisphenol A

• Tao Wang,
• Yan-Chao Zhao,
• Li-Min Zhang,
• Yi Cui,
• Chang-Shan Zhang and
• Bao-Hang Han

Beilstein J. Org. Chem. 2017, 13, 2131–2137, doi:10.3762/bjoc.13.211

• organic polymers (POPs) have been reported via Sonogashira–Hagihara coupling reaction [16], Suzuki–Miyaura chemistry [17], Yamato reaction [18], and self condensation of aromatic nitriles[19]. Although these methods can be used to construct POPs with high specific surface area values, these reactions are

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

Mechanochemical synthesis of small organic molecules

• Tapas Kumar Achar,
• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

• -free Wittig reaction of organic halides with aldehydes or ketones (Scheme 6) [55]. Suzuki Coupling In 2000, Peters and co-workers first reported the palladium-catalyzed Suzuki coupling reaction under ball-milling conditions [56]. In a planetary mill for 30–60 min, the mixture of aryl halide (1.0 equiv

• ), phenylboronic acid (2.0 equiv), K2CO3 (3.0 equiv) and Pd(PPh3)4 (5 mol %) resulted in coupled products with 96% yield (Scheme 7). The NaCl was used as an additive to make the reaction mixture sufficiently powdery for uniform mixing. The use of aryl chlorides is generally restricted in Suzuki reactions because

• of their low reactivity. Recently, Li and Su with co-workers have developed a liquid-assisted grinding (LAG) method for the Suzuki–Miyaura coupling between aryl chlorides and boronic acids to synthesize the biaryls in nearly quantitative yield. Under optimized conditions 2 mol % Pd(OAc)2 and 4 mol

An efficient Pd–NHC catalyst system in situ generated from Na₂PdCl₄ and PEG-functionalized imidazolium salts for Mizoroki–Heck reactions in water

• Nan Sun,
• Meng Chen,
• Liqun Jin,
• Wei Zhao,
• Baoxiang Hu,
• Zhenlu Shen and
• Xinquan Hu

Beilstein J. Org. Chem. 2017, 13, 1735–1744, doi:10.3762/bjoc.13.168

• contributed to Suzuki–Miyaura reactions and only a very few examples were reported for Mizoroki–Heck reactions [45][51][53][57]. Previous research by Rösch and other groups disclosed that introducing a hemilable donor group (such as N, O, S etc.) on the NHC rings was favorable for the palladium-catalyzed