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

• transformation is proposed in Scheme 33 below. Notably, Cu acts as both a mediator and an oxidizer in this reaction. In the same year, Daugulis et al. [78] presented a Cu-catalyzed selective fluorination of benzoic acid derivatives and benzylamine derivatives assisted by an aminoquinoline auxiliary. With a CuI

• Cu-catalyzed fluorination of 2-pyridylaryl bromides was achieved by Liu and co-workers [80] through a Cu(I/III) catalytic cycle as well (Scheme 36). This method is based on the aid of an important pyridyl directing group and the final aryl C–F bond is formed after the reductive elimination of ArCu

Synthesis of benzo[d]imidazo[2,1-b]benzoselenoazoles: Cs₂CO₃-mediated cyclization of 1-(2-bromoaryl)benzimidazoles with selenium

• Mio Matsumura,
• Yuki Kitamura,
• Arisa Yamauchi,
• Yoshitaka Kanazawa,
• Yuki Murata,
• Tadashi Hyodo,
• Kentaro Yamaguchi and
• Shuji Yasuike

Beilstein J. Org. Chem. 2019, 15, 2029–2035, doi:10.3762/bjoc.15.199

• Ar(aryl)–Se bonds [9][10][11][12][13]. Various metals, such as Pd, Ni, Fe, and Cu have been used to catalyze the reactions of a Se source with aryl donors. Among these, Cu-catalyzed tandem cyclization via a one-step Ullmann-type Se-arylation and Csp2–H selenation are efficient methods for

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

• of biologically active imidazo[1,2-a] pyridine derivatives [108]. Encouraged by the direct synthetic strategies for imidazo[1,2-a]pyridines (IPs), Donthiri et al. have reported an efficient Cu-catalyzed C–H functionalization of pyridines with vinyl azide derivatives [109]. Their use of vinyl azide

Selenophene-containing heterotriacenes by a C–Se coupling/cyclization reaction

• Pierre-Olivier Schwartz,
• Sebastian Förtsch,
• Astrid Vogt,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2019, 15, 1379–1393, doi:10.3762/bjoc.15.138

• starting material, but also ring fusion to selenophene was achieved by Cu-catalyzed C–Se cross-coupling reaction [28]. The detailed geometric structure and the packing behaviour in the solid state of triacenes 2–4 have been elucidated by single crystal X-ray structure analysis and X-ray diffraction on

• reinvestigated the synthesis of DTT 1 by using a Cu-catalyzed C–S cross-coupling reaction with potassium sulfide (K2S) as sulfur source [29]. The best results for this C–S ring-closure reaction were achieved by reacting 3,3’-diiodo-2,2’-bithiophene (5) [30] with the system K2S and copper iodide (CuI) as catalyst

• reagents as aforementioned or DTT 1 with thiourea or thioacetate in a Pd-catalyzed reaction [33] led in both cases to substantially lower yields. For the synthesis of selenolotriacenes (DST) 3 and (DSS) 4 we followed the same strategies and applied the above described Cu-catalyzed C–S and C–Se cross

Synthesis of non-racemic 4-nitro-2-sulfonylbutan-1-ones via Ni(II)-catalyzed asymmetric Michael reaction of β-ketosulfones

• Alexander N. Reznikov,
• Anastasiya E. Sibiryakova,
• Marat R. Baimuratov,
• Eugene V. Golovin,
• Victor B. Rybakov and
• Yuri N. Klimochkin

Beilstein J. Org. Chem. 2019, 15, 1289–1297, doi:10.3762/bjoc.15.127

• cytotoxicity [9]. However, it is of great importance to obtain all stereoisomers for the study of biological activity. Therefore, the development of methods for the asymmetric synthesis of polyfunctional sulfones is valuable. The most notable of them are Ag- and Cu-catalyzed 1,3-dipolar cycloaddition reactions

• , which allows to obtain chiral cyclic sulfones with high enantioselectivity [10][11][12]. Also non-racemic cyclic sulfones can be obtained by the Diels–Alder reaction, catalyzed by chiral Lewis acids or organocatalysts. Rh- and Cu-catalyzed CH-insertion reactions occurring at moderate or high

Silanediol versus chlorosilanol: hydrolyses and hydrogen-bonding catalyses with fenchole-based silanes

• Falco Fox,
• Jörg M. Neudörfl and
• Bernd Goldfuss

Beilstein J. Org. Chem. 2019, 15, 167–186, doi:10.3762/bjoc.15.17

• , BIFOL, Figure 1) [52][54] and it´s derivative, the chiral chlorophosphite ligand 6 (BIFOP-Cl, Figure 1), e.g., in Cu-catalyzed 1,4-additions [53], in Pd-catalyzed alkyl–aryl cross coupling reactions [55][56], as well as for organoaluminum fencholate reagents [57]. Unexpected stability against hydrolysis

Cobalt- and rhodium-catalyzed carboxylation using carbon dioxide as the C1 source

• Tetsuaki Fujihara and
• Yasushi Tsuji

Beilstein J. Org. Chem. 2018, 14, 2435–2460, doi:10.3762/bjoc.14.221

• Negishi coupling with aryl bromide, affording the corresponding sterically congested alkene 17b-Ar in 56% yield after two steps. The Negishi coupling with benzyl chloride and the Cu-catalyzed allylation of allyl bromide also afforded the corresponding products 17b-Bn and 17b-Allyl, respectively, in good

• species B (step a). Finally, transmetalation between B and the arylboronic ester affords the product, along with the aryl-Rh intermediate A (step b) After this contribution, the Cu-catalyzed carboxylation of aryl and alkenylboronic esters was independently reported by the groups of Iwasawa and How [55][56

• ]. Direct C(sp2)–H bond carboxylation As described above, C–H carboxylations with CO2, particularly C(sp2)–H carboxylation reactions, have attracted much research interest. As a consequence, Nolan [57] and Hou [58] independently reported Cu-catalyzed carboxylations using heteroarenes as substrates, which

Cobalt-catalyzed peri-selective alkoxylation of 1-naphthylamine derivatives

• Jiao-Na Han,
• Cong Du,
• Xinju Zhu,
• Zheng-Long Wang,
• Yue Zhu,
• Zhao-Yang Chu,
• Jun-Long Niu and
• Mao-Ping Song

Beilstein J. Org. Chem. 2018, 14, 2090–2097, doi:10.3762/bjoc.14.183

• structural units present in many natural products, functional materials, and pharmaceuticals [1]. Consequently, a variety of strategies have emerged to access them, including Pd-catalyzed and Cu-catalyzed coupling reactions (Buchwald–Harting couplings and Ullmann reactions) [2][3][4]. However, these classic

Hyper-reticulated calixarene polymers: a new example of entirely synthetic nanosponge materials

• Alberto Spinella,
• Marco Russo,
• Antonella Di Vincenzo,
• Delia Chillura Martino and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2018, 14, 1498–1507, doi:10.3762/bjoc.14.127

• extend and possibly improve the supramolecular binding abilities of CyNSs, mixed cyclodextrin-calixarene co-polymers nanosponges (CyCaNSs) were recently synthesized by exploiting a classical “click-chemistry” approach, namely the CuAAC reaction (Cu-catalyzed azide–alkyne cycloaddition [28][29][30

Metal-free formal synthesis of phenoxazine

• Gabriella Kervefors,
• Antonia Becker,
• Chandan Dey and
• Berit Olofsson

Beilstein J. Org. Chem. 2018, 14, 1491–1497, doi:10.3762/bjoc.14.126

• recently, Bolm and co-workers reported a metal-free cyclization of iodo-substituted diaryl ethers with a broad scope (Scheme 1b) [18]. Transition metal-catalyzed cross couplings have also been employed to form the required C–O and C–N bonds, e.g., by Cu-catalyzed cyclization of 2-(2-bromophenoxy)anilines

Sequential Ugi reaction/base-induced ring closing/IAAC protocol toward triazolobenzodiazepine-fused diketopiperazines and hydantoins

• Robby Vroemans,
• Fante Bamba,
• Jonas Winters,
• Joice Thomas,
• Jeroen Jacobs,
• Luc Van Meervelt,
• Jubi John and
• Wim Dehaen

Beilstein J. Org. Chem. 2018, 14, 626–633, doi:10.3762/bjoc.14.49

• heterocycle formation and the other an IAAC. Unlike some of the reported strategies using Cu-catalyzed IAAC [13][15], we postulated that the intramolecular dipolar cycloaddition would proceed under thermal conditions (metal-free) due to the close proximity of the azide and similar functionalities in the

Progress in copper-catalyzed trifluoromethylation

• Guan-bao Li,
• Chao Zhang,
• Chun Song and
• Yu-dao Ma

Beilstein J. Org. Chem. 2018, 14, 155–181, doi:10.3762/bjoc.14.11

• was paid on trifluoroacetates. Trifluoroacetate is readily available and one of the cheapest and most convenient sources of the trifluoromethylation for both industrial and medicinal purposes. In 2011, a practical and ligand-free Cu-catalyzed decarboxylative trifluoromethylation of aryl iodides was

• explored the trifluoromethylation of primary and secondary alkylboronic acids with the Ruppert–Prakash reagent (TMSCF3) (Scheme 17) [32]. These alkylboronic acids were prepared from the corresponding alkyl halides or tosylates by using their previously developed Cu-catalyzed borylation method [33]. Both

• allylic CF3 bonds from olefins. Following examples described the straightforward trifluoromethylation of terminal alkenes via allylic C(sp3)–H bond activation generating allylic trifluoromethylated compounds. In 2011, the group of Fu and Liu [49] described an unprecedented type of a Cu-catalyzed

Ni nanoparticles on RGO as reusable heterogeneous catalyst: effect of Ni particle size and intermediate composite structures in C–S cross-coupling reaction

• Debasish Sengupta,
• Koushik Bhowmik,
• Goutam De and
• Basudeb Basu

Beilstein J. Org. Chem. 2017, 13, 1796–1806, doi:10.3762/bjoc.13.174

• reductive elimination. A more detailed study describing Pd- or Cu-catalyzed C–S coupling reactions as compared to Ni-catalyzed reaction has been published [7][53][54]. However, as proposed in previous investigations on the Ni-catalyzed C–S coupling reaction [15][22][23], the catalytic cycle here is likely

Strategies toward protecting group-free glycosylation through selective activation of the anomeric center

• A. Michael Downey and
• Michal Hocek

Beilstein J. Org. Chem. 2017, 13, 1239–1279, doi:10.3762/bjoc.13.123

• conditions were feasible for the synthesis of glycosyl azides which are highly useful precursors for N-linked glycans [95] or Cu-catalyzed cycloadditions with alkynes (as shown above) [85]. By using tetrabutylammonium chloride and an amine base the highly reactive chlorinated intermediate forms that can be

An eco-compatible strategy for the diversity-oriented synthesis of macrocycles exploiting carbohydrate-derived building blocks

• Sushil K. Maurya and
• Rohit Rana

Beilstein J. Org. Chem. 2017, 13, 1106–1118, doi:10.3762/bjoc.13.110

• attached through Cu-catalyzed azide–alkyne cycloaddition (CuAAC) reaction (couple phase). Noteworthy, herein we utilized the CuAAC reaction as a medium for coupling different building blocks assembled iteratively to generate a 1,2,3-triazole moiety. This 1,2,3-triazole moiety linked as a spacer due to its

Energy down converting organic fluorophore functionalized mesoporous silica hybrids for monolith-coated light emitting diodes

• Markus Börgardts and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2017, 13, 768–778, doi:10.3762/bjoc.13.76

• functionalization can be achieved upon ligating a triethylsiloxy-functionalized azide and a terminal alkynyl-functionalized luminophore by CuAAC (Cu-catalyzed azide–alkyne cycloaddition) [21][22][23]. Commencing from a 2-hydroxy-substituted Nile red 1 or 3-hydroxymethylperylene (2) the alkyne-substituted

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

• arylation of aminocholanes has been described for the first time. While this Cu-catalyzed protocol provides high yields in reactions of aminocholanes with iodoarenes, Pd catalysis was found to be preferable for the reactions of aminocholanes with dichloroanthraquinones. UV–vis titration of bis(cholanylamino

• arylaminocholanes and cholane-diaminoanthraquinone derivatives by Pd- and Cu-catalyzed amination. Such compounds not only have cation binding properties, but also might be easily introduced in lipid membranes to form ion channels. Appropriate close location of lipophilic steroid fragments in bis(cholanediamino

• LiAlH4 (Scheme 2) [37]. Cu-catalyzed amination is known to be a very efficient approach for C–N bond formation [38][39]. The availability of the variety of inexpensive ligands for copper(I) is a crucial benefit in comparison to the Pd-catalyzed variant. Primary amines of different structures can readily

Fast and efficient synthesis of microporous polymer nanomembranes via light-induced click reaction

• Qi An,
• Youssef Hassan,
• Xiaotong Yan,
• Peter Krolla-Sidenstein,
• Tawheed Mohammed,
• Mathias Lang,
• Stefan Bräse and
• Manuel Tsotsalas

Beilstein J. Org. Chem. 2017, 13, 558–563, doi:10.3762/bjoc.13.54

• solid liquid interfacial layer-by-layer (LbL) synthesis of CMP-nanomembranes via Cu catalyzed azide–alkyne cycloaddition (CuAAC). However, this process featured very long reaction times and limited scalability. Herein we present the synthesis of surface grown CMP thin films and nanomembranes via light

Direct arylation catalysis with chloro[8-(dimesitylboryl)quinoline-κN]copper(I)

• Sem Raj Tamang and
• James D. Hoefelmeyer

Beilstein J. Org. Chem. 2016, 12, 2757–2762, doi:10.3762/bjoc.12.272

• substitution ratio is typical of substitutions on naphthalene under kinetic control that tend to favor the alpha C–H bonds due better resonance stabilization effects [53]. Importantly, we note the alpha protons are slightly more acidic than the beta protons [54]. The mechanism of Cu catalyzed coupling

Facile synthesis of indolo[3,2-a]carbazoles via Pd-catalyzed twofold oxidative cyclization

• Chao Yang,
• Kai Lin,
• Lan Huang,
• Wei-dong Pan and
• Sheng Liu

Beilstein J. Org. Chem. 2016, 12, 2490–2494, doi:10.3762/bjoc.12.243

• Houpis protocol [15], Cu-catalyzed selective monoaminations of the 2,4-dibromobenzoic acid at the 2-position were achieved. After methyl esterification of ortho-aminated benzoic acids, substrates 4a and b were treated with other anilines under the previous Buchwald–Hartwig conditions to afford methyl 2,4

Synthesis, dynamic NMR characterization and XRD studies of novel N,N’-substituted piperazines for bioorthogonal labeling

• Constantin Mamat,
• Marc Pretze,
• Matthew Gott and
• Martin Köckerling

Beilstein J. Org. Chem. 2016, 12, 2478–2489, doi:10.3762/bjoc.12.242

• to demonstrate the Cu-catalyzed azide–alkyne click reaction (Huisgen 1,3-dipolar cycloaddition) and the traceless Staudinger ligation, a proof of concept study was performed for the site-selective labeling of a pharmacologically active peptide and a small organic compound. These compounds provide the

• , 3a,b were alkylated with 4-tosylbutyne to give compounds 4a,b in high yields of 84% and 82%, respectively. These compounds are applicable in the classical Cu-catalyzed Huisgen-click reaction with azide-functionalized, biologically active molecules. Additionally, 3a,b were reacted with 3-azidopropyl

• isomers in a 1:1 ratio as imposed by crystal symmetry. Sample ligation using Huisgen-click and traceless Staudinger As a proof of labeling concept, fluorine compound 4b was clicked to peptide 6 using the Cu-catalyzed Huisgen-click reaction. This SNEW peptide (SNEW: Ser-Asn-Glu-Trp) was chosen due to its

Enantioconvergent catalysis

• Justin T. Mohr,
• Jared T. Moore and
• Brian M. Stoltz

Beilstein J. Org. Chem. 2016, 12, 2038–2045, doi:10.3762/bjoc.12.192

• generation of radical intermediates from chiral sp3-hybridized halides presents another opportunity for type II enantioconvergent catalysis. Peters and Fu have reported a system for the Cu-catalyzed C–N cross-coupling of racemic tertiary alkyl halide electrophiles with carbazole nucleophiles induced by

• . Enantioconvergent synthesis of phosphines governed by Curtin–Hammett/Winstein–Holness kinetics (TMS = trimethylsilyl, Is = 2,4,6-triisopropylphenyl). Stoltz’ stereoablative oxindole functionalization. Fu’s type II enantioconvergent Cu-catalyzed photoredox reaction. Stereoablative enantioconvergent allylation and

Copper-catalyzed [3 + 2] cycloaddition of (phenylethynyl)di-p-tolylstibane with organic azides

• Mizuki Yamada,
• Mio Matsumura,
• Yuki Uchida,
• Masatoshi Kawahata,
• Yuki Murata,
• Naoki Kakusawa,
• Kentaro Yamaguchi and
• Shuji Yasuike

Beilstein J. Org. Chem. 2016, 12, 1309–1313, doi:10.3762/bjoc.12.123

• University, 1314-1 Shido, Sanuki, Kagawa 769-2193, Japan Faculty of Pharmaceutical Sciences, Hokuriku University, Ho-3 Kanagawa-machi, Kanazawa 920-1181, Japan 10.3762/bjoc.12.123 Abstract Trisubstituted 5-stibano-1H-1,2,3-triazoles were synthesized in moderate to excellent yields by the Cu-catalyzed [3 + 2

• -triazoles (Bi), which could be employed as versatile building blocks in chemical synthesis [24]. One drawback of the Cu-catalyzed cycloaddition of alkynylbismuthanes is the requirement of alkyne derivatives based on the phenothiabismuthane 5,5-dioxide framework for stabilization. The utility of

• present. We consider that the catalytic cycle of this reaction would be similar to that for the reaction of 1-iodoalkynes [21][33] and 1-bismuthanoalkynes [24] with organic azides. A possible mechanism of the present Cu-catalyzed cycloaddition is shown in Scheme 2. Initially, π-complex A is generated by

Palladium-catalyzed picolinamide-directed iodination of remote ortho-C−H bonds of arenes: Synthesis of tetrahydroquinolines

• William A. Nack,
• Xinmou Wang,
• Bo Wang,
• Gang He and
• Gong Chen

Beilstein J. Org. Chem. 2016, 12, 1243–1249, doi:10.3762/bjoc.12.119

• iodination, and Cu-catalyzed C−N cyclization enables a streamlined synthesis of tetrahydroquinolines bearing diverse substitution patterns. Keywords: iodination; palladium; remote C–H activation; tetrahydroquinoline; Introduction Tetrahydroquinoline (THQ) is an important N-heterocyclic scaffold found in

• cyclized under our previously reported Cu-catalyzed conditions to give PA-coupled THQ products with various substitution patterns in good yields (Scheme 2) [8]. As shown in Scheme 2, Pd-catalyzed PA-directed ε-C−H iodination can be used in concert with PA-directed γ-C−H arylation, PA-directed SEAr

• iodination, and undirected SEAr iodination to quickly access THQs 27–30 bearing iodo groups at different positions on the arene ring [40][41][42]. Ortho-diiodinated product 4 was obtained from 2 in 69% yield using optimized Pd-catalyzed ε-C–H iodination conditions, and Cu-catalyzed C–N cyclization of 4 gave

Catalytic asymmetric synthesis of biologically important 3-hydroxyoxindoles: an update

• Bin Yu,
• Hui Xing,
• De-Quan Yu and
• Hong-Min Liu

Beilstein J. Org. Chem. 2016, 12, 1000–1039, doi:10.3762/bjoc.12.98

• tolerance were observed. However, no reaction occurred between the ortho-chloro substituted 1,3-diaryl-2-propenyl acetate and 3-O-Boc-oxindole because the chlorine atom inhibited the formation of the active π-allyl-palladium species. Cu-catalyzed direct addition The copper catalysts have gained an