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

• anticancer activity are described. The double C–H selenation of imidazo[1,2-a]pyridine with Se powder was catalyzed by CuI (10 mol %) ligated with 1,10-phenanthroline (10 mol %) at 130 °C under aerobic conditions. The selenides or diselenides were prepared almost selectively using selenium powder in an

• -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

• , and aryl halides in the presence of Na2CO3 (2 equiv) using a NiBr2/2,2-bipyridine system [31]. We also developed reactions of imidazopyridines, Se powder, and triarylbismuthanes using a CuI/1,10-phenanthroline catalytic system that did not require a base or an additive [32]. On the other hand, the

Copper-based fluorinated reagents for the synthesis of CF₂R-containing molecules (R ≠ F)

• Louise Ruyet and
• Tatiana Besset

Beilstein J. Org. Chem. 2020, 16, 1051–1065, doi:10.3762/bjoc.16.92

• ) and 1,10-phenanthroline as a ligand was crucial in their system. In 2012, Prakash also studied the in situ generation of CuCF2H from n-Bu3SnCF2H, the presence of DMF being the key to stabilize the CuCF2H intermediate [41] (Scheme 2). From these seminal works, a handful of reports was then published by

• -generated copper-based reagent (19 examples, up to 80% yield, Scheme 7e). With a similar method and in the presence of 1,10-phenanthroline as a ligand, the functionalization of alkenyl halides (8 examples, up to 82% yield), allyl halides (7 examples, up to 99% yield) and benzyl bromides (6 examples, up to

• reagents for perfluoroalkylation reactions [66], Hartwig developed in 2011 the (Phen)CuCF3 and (Phen)CuCF2CF2CF3 complexes from inexpensive reagents. Indeed, when mixing (CuOt-Bu)4, 1,10-phenanthroline and the corresponding TMSRF, the perfluoroalkyl copper complexes were isolated for the first time (Scheme

A systematic review on silica-, carbon-, and magnetic materials-supported copper species as efficient heterogeneous nanocatalysts in “click” reactions

• Pezhman Shiri and
• Jasem Aboonajmi

Beilstein J. Org. Chem. 2020, 16, 551–586, doi:10.3762/bjoc.16.52

• triazole products, excellent reusability, short reaction times, and good to high yields. Further, Dufauda et al. reported a copper(II)–phenanthroline complex supported on the SBA-15 architecture, Cu(II)phen@SBA-15 (58) [31]. The preparation is outlined in Scheme 9: Initially, phen-functionalized mesoporous

Controlling alkyne reactivity by means of a copper-catalyzed radical reaction system for the synthesis of functionalized quaternary carbons

• Goki Hirata,
• Yu Yamane,
• Naoya Tsubaki,
• Reina Hara and
• Takashi Nishikata

Beilstein J. Org. Chem. 2020, 16, 502–508, doi:10.3762/bjoc.16.45

• with good regio- and stereoselectivity. Results and Discussion In our preliminary research, we tried various Cu salts, including CuI, CuBr, CuCl, CuOAc, and CuOTf, and ligands, including PPh3, 1,10-phenanthroline (1,10-Phen), N,N,N',N'',N''-pentamethyldiethylenetriamine, and tris(2-pyridylmethyl)amine

Recent advances in photocatalyzed reactions using well-defined copper(I) complexes

• Mingbing Zhong,
• Xavier Pannecoucke,
• Philippe Jubault and
• Thomas Poisson

Beilstein J. Org. Chem. 2020, 16, 451–481, doi:10.3762/bjoc.16.42

• bisnitrogen ligands, and particularly phenanthroline derivatives, were used in the pioneering reports from McMillin [14] and Sauvage [15]. For decades, their use in organic synthesis, and particularly catalysis, has been ignored. However, since 2012, a renewed interest toward their use in catalysis has been

• chlorotrifluoromethylated product (Scheme 3). In 2019, Bissember and co-workers reported the synthesis of new homoleptic copper complexes by modifying the structure of the phenanthroline ligand at the 1- and 10-positions with various aromatic substituents [19]. These complexes were fully characterized and evaluated in a

• phenanthroline derivative and a bisisonitrile ligand, [Cu(I)(dpp)(binc)]BF4, which was fully characterized (Scheme 15) [32]. This complex proved to have a similar or higher excited state lifetime (17 μs) compared to the previously reported complexes and a redox potential of −1.88 V vs SCE in the excited state

Six-fold C–H borylation of hexa-peri-hexabenzocoronene

• Mai Nagase,
• Kenta Kato,
• Akiko Yagi,
• Yasutomo Segawa and
• Kenichiro Itami

Beilstein J. Org. Chem. 2020, 16, 391–397, doi:10.3762/bjoc.16.37

• borylation of unsubstituted HBC. HBC was pulverized by a ball mill prior to use. First, we attempted the iridium catalyst and reagents that we have reported as the suitable C–H borylation conditions for warped nanographene: [Ir(OMe)cod]2, 3,4,7,8-tetramethyl-1,10-phenanthroline (tmphen), HBpin (Bpin: 4,4,5,5

• stirring bar was added HBC (10.0 mg, 19.1 μmol, 1.0 equiv). The flask was put in an argon-filled glove box, and a solution of [Ir(OMe)cod]2 (1.9 mg, 2.9 μmol, 15 mol %) and 3,4,7,8-tetramethyl-1,10-phenanthroline (tmphen; 1.4 mg, 5.9 μmol, 31 mol %) in a dry solvent (300 μL) was added to the flask. Then

Photoreversible stretching of a BAPTA chelator marshalling Ca²⁺-binding in aqueous media

• Aurélien Ducrot,
• Arnaud Tron,
• Robin Bofinger,
• Ingrid Sanz Beguer,
• Jean-Luc Pozzo and
• Nathan D. McClenaghan

Beilstein J. Org. Chem. 2019, 15, 2801–2811, doi:10.3762/bjoc.15.273

• spectrofluorometer fitted with a PMT detector and exciting with a 450 W Xe lamp across a double monochromator, and were corrected for instrumental response. Photoreaction quantum yields were determined upon excitation at 365 nm using the couple potassium ferrioxalate–phenanthroline as a chemical actinometer on an

Photochromic diarylethene ligands featuring 2-(imidazol-2-yl)pyridine coordination site and their iron(II) complexes

• Andrey G. Lvov,
• Max Mörtel,
• Anton V. Yadykov,
• Frank W. Heinemann,
• Valerii Z. Shirinian and
• Marat M. Khusniyarov

Beilstein J. Org. Chem. 2019, 15, 2428–2437, doi:10.3762/bjoc.15.235

• ligand systems, including 1,10-phenanthroline, 2-(azol-2-yl)pyridine, and related frameworks to yield photochromic ligands. The latter can be divided into two groups based on the position of the metal coordination site relative to the photoactive hexatriene unit of a diarylethene. Some diarylethene-based

• , resulted in the hypsochromic shift of long-wavelength absorption band, which could be due to keto–enol tautomerization in the ethene bridge [43]. Overall, the thermal stabilities of the new ligands are comparable to those of phenanthroline-based photochromic ligand I [19]. Synthesis and structure of iron

• synthesized. All ligands show good combinations of cyclization/cycloreversion quantum yields, whereas the thermal stability of closed-ring isomers is comparable with those reported for a diarylethene-based ligand with a phenanthroline bridge. Cyclohexenone ligand 6 readily forms a dimeric complex 8 with “FeII

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

• phenanthroline derivative. This complex was applied to the SN2 fluorination of primary and secondary alkyl bromides, producing the corresponding alkyl fluorides in 40–90% yield (Scheme 26). In 2014, the group of Lalic [69] developed a mild fluorination of alkyl triflates with potassium fluoride catalyzed by a

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

Synthesis of 9-O-arylated berberines via copper-catalyzed C_Ar–O coupling reactions

• Qiaoqiao Teng,
• Xinhui Zhu,
• Qianqian Guo,
• Weihua Jiang,
• Jiang Liu and
• Qi Meng

Beilstein J. Org. Chem. 2019, 15, 1575–1580, doi:10.3762/bjoc.15.161

• -alkylated BBR, the synthesis of 9-O-phenyl BBR 3a was initially attempted by direct cross-coupling of berberrubine (BBRB) with phenyl iodide, using CuI and 1,10-phenanthroline as the pre-catalyst and K2CO3 as the base [18][19]. However, under these reaction conditions not any desired product was formed, and

Complexation of a guanidinium-modified calixarene with diverse dyes and investigation of the corresponding photophysical response

• Yu-Ying Wang,
• Yong Kong,
• Zhe Zheng,
• Wen-Chao Geng,
• Zi-Yi Zhao,
• Hongwei Sun and
• Dong-Sheng Guo

Beilstein J. Org. Chem. 2019, 15, 1394–1406, doi:10.3762/bjoc.15.139

• photophysical behavior of Ru(II) complexes affected by calixarenes has been studied by different groups. Kirsch-De Mesmaeker and co-workers reported that the luminescence of [Ru(TAP)2(phen)]2+ (TAP = 1,4,5,8-tetraazaphenanthrene, phen = 1,10-phenanthroline) complex could be quenched by the phenol moieties of a

Selective detection of DABCO using a supramolecular interconversion as fluorescence reporter

• Indrajit Paul,
• Debabrata Samanta,
• Sudhakar Gaikwad and
• Michael Schmittel

Beilstein J. Org. Chem. 2019, 15, 1371–1378, doi:10.3762/bjoc.15.137

• equipped with a trimethoxyphenyl group to furnish a fourth coordination to the copper(I) center and a sterically crowded duryl group to prevent homoleptic complexation, while lutidine 9 was selected to strengthen the HETPYP-I [33] (HETeroleptic PYridine and Phenanthroline complexation) coordination. In

• this setting, the binary complex 12 = [(4)(10)2] and the heteroleptic metal complex 11 = [Cu(8)(9)]+ quantitatively formed side by side in a two-fold completive self-sorting. Lutidine 9 has a higher binding preference towards the copper phenanthroline [Cu(8)]+ (log K(9)·[Cu(8)]+ = 4.60 ± 0.21

• phenanthroline and very similar to the one experienced by the methyl protons (f2’-H) that are diagnostically shifted upfield to −0.63 ppm. Proton h-H is equally split into two sets reflecting the strong coordination of one methoxy group at an unsymmetrically coordinated copper(I) center. Similar to model system

Synthesis of aryl cyclopropyl sulfides through copper-promoted S-cyclopropylation of thiophenols using cyclopropylboronic acid

• Emeline Benoit,
• Ahmed Fnaiche and
• Alexandre Gagnon

Beilstein J. Org. Chem. 2019, 15, 1162–1171, doi:10.3762/bjoc.15.113

• the solvent for toluene, dichloromethane, dimethylformamide or DMF/H2O (4:1) led to lower yields of the desired aryl cyclopropyl sulfide 1a (Table 1, entry 5) while decreasing the temperature to 50 °C almost completely shut down the reaction (Table 1, entry 6). 1,10-Phenanthroline was found to be the

• (II) acetate, 0.1 equivalents of 1,10-phenanthroline, 2.0 equivalents of potassium carbonate under oxygen atmosphere at 70 °C for 20 hours in a 3:1 mixture of toluene and water afforded the aryl cyclopropyl sulfide 1a in 38% along with 8% of the corresponding side-product 26a and 24% of recovered

Mechanochemistry of supramolecules

• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2019, 15, 881–900, doi:10.3762/bjoc.15.86

• appropriate metal ion(s) and ligand(s) has been demonstrated in various reports [46][47][48][49]. In Figure 1, a comprehensive framework is shown in which nanoscale architectures are built from various monodentate (pyridine; Figure 1a), bidentate (bipyridine, phenanthroline; Figure 1b) and tridentate

Organometallic vs organic photoredox catalysts for photocuring reactions in the visible region

• Aude-Héloise Bonardi,
• Frédéric Dumur,
• Guillaume Noirbent,
• Jacques Lalevée and
• Didier Gigmes

Beilstein J. Org. Chem. 2018, 14, 3025–3046, doi:10.3762/bjoc.14.282

• )-complexes have been widely used. For example, bis(1,10-phenanthroline)copper(I) (abbreviated Cu(phen)22+) is reported in ref [37] as an efficient photoredox catalyst for ATRP upon a simple household blue LED. Ir-based photoredox catalyst are also efficient in this mechanism such as tris(2-phenylpyridinato

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

• -phenanthroline) and Mn powder (3.0 equiv) in N,N-dimethylacetamide (DMA) under an atmospheric pressure of CO2 at room temperature (Scheme 1). Under optimized reaction conditions, the carboxylated product 2a-Me was obtained in 83% yield after derivatization to the corresponding methyl ester. In the absence of the

• -phenanthroline) as the catalyst, 4a-Me was obtained in 86% yield after esterification. Other bidentate ligands such as bpy, phen, and dppe were not suitable for this reaction. Control experiments revealed that both the Co catalyst and the Mn reductant were indispensable to the reaction. The carboxylation of

Tetrathiafulvalene – a redox-switchable building block to control motion in mechanically interlocked molecules

• Hendrik V. Schröder and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2018, 14, 2163–2185, doi:10.3762/bjoc.14.190

• similar. The motion which can be controlled by external stimuli is the rotation (or circumrotation) of the wheels relative to each other. The first TTF-based catenane 25 was described by the groups of Becher and Sauvage in 1994 (Figure 23) [100]. Starting from a phenanthroline macrocycle bearing a TTF

Revisiting ring-degenerate rearrangements of 1-substituted-4-imino-1,2,3-triazoles

• James T. Fletcher,
• Matthew D. Hanson,
• Joseph A. Christensen and
• Eric M. Villa

Beilstein J. Org. Chem. 2018, 14, 2098–2105, doi:10.3762/bjoc.14.184

• ][14][15][16][17], quinoline [18][19], pyridazine [20][21], phthalazine [22], benzimidazole [23], phenanthroline [24], bipyridine [25] and amine [26] subunits. The utility of such chelators in constructing coordination compounds has been demonstrated for a wide range of transition metal and lanthanide

Cationic cobalt-catalyzed [1,3]-rearrangement of N-alkoxycarbonyloxyanilines

• Itaru Nakamura,
• Mao Owada,
• Takeru Jo and
• Masahiro Terada

Beilstein J. Org. Chem. 2018, 14, 1972–1979, doi:10.3762/bjoc.14.172

• 2-aminophenol derivative 2a (Table 1, entries 3 and 4). Moreover, a cationic copper catalyst generated from CuCl2 and two equivalents of AgSbF6 was effective to afford 2a in good yield (Table 1, entry 5), even at 30 °C (Table 1, entry 8). The use of a ligand, such as 1,10-phenanthroline (phen) and

Efficient catenane synthesis by cucurbit[6]uril-mediated azide–alkyne cycloaddition

• Antony Wing Hung Ng,
• Chi-Chung Yee,
• Kai Wang and
• Ho Yu Au-Yeung

Beilstein J. Org. Chem. 2018, 14, 1846–1853, doi:10.3762/bjoc.14.158

• a preliminary study of a [6]catenane synthesis featuring the CB[6]-mediated azide–alkyne cycloaddition (CBAAC) using phenanthroline-based building blocks [24]. To further explore the applicability and generality of the CBAAC in the construction of mechanically interlocked molecules, we report here

• other topological isomers. The building blocks contain either a central hexaethylene glycol (HEG) unit or are derived from 1,5-dioxynaphthalene (DN), naphthalenediimide (NDI), 2,9-phenanthroline (Phen) or 4,4’-biphenyl (BP) cores which can engage in additional non-covalent interactions, such as metal

• ). Together with our previous demonstration of the compatibility of CBAAC with Cu+-phenanthroline coordination in a [6]catenane assembly, the successful synthesis of Cat-11 shows the feasibility of using CBAAC with a versatile selection of building blocks and non-covalent interactions to construct complex

Synthesis and photophysical studies of a multivalent photoreactive Ru^II-calix[4]arene complex bearing RGD-containing cyclopentapeptides

• Sofia Kajouj,
• Lionel Marcelis,
• Alice Mattiuzzi,
• Adrien Grassin,
• Damien Dufour,
• Pierre Van Antwerpen,
• Didier Boturyn,
• Eric Defrancq,
• Mathieu Surin,
• Julien De Winter,
• Pascal Gerbaux,
• Ivan Jabin and
• Cécile Moucheron

Beilstein J. Org. Chem. 2018, 14, 1758–1768, doi:10.3762/bjoc.14.150

• in the IR spectrum of 4. Phenanthroline derivative 5 was synthesized from 5-glycinamido-1,10-phenanthroline in a two-step sequence consisting of a peptide-type coupling reaction with a Boc-protected glycine N-hydrosuccinimide ester followed by the deprotection of the amino group (see Supporting

• Information File 1) [71]. Different coupling agents (DCC/HOBt, EDC·HCl/HOBt, PyBOP) and conditions were then tested for the peptide-type coupling reaction between calix[4]arene 4 and phenanthroline derivative 5. The use of an excess of 5 (2 equiv) in the presence of EDC·HCl and HOBt in DMF at room temperature

• Information File 1. Calix[4]arenes 2 and 3 were synthesized from commercial p-tert-butylcalix[4]arene 1 according to procedures described in the literature [69]. The experimental procedures and characterization data for calixarene derivatives 4, 6, 7 and 9, phenanthroline derivative 5 and c-[RGDfK]-alkyne 8

β-Hydroxy sulfides and their syntheses

• Mokgethwa B. Marakalala,
• Edwin M. Mmutlane and
• Henok H. Kinfe

Beilstein J. Org. Chem. 2018, 14, 1668–1692, doi:10.3762/bjoc.14.143

• excellent catalyst for the thiolysis and selenolysis of meso-epoxides to give the corresponding β-hydroxy derivatives in good yields and high enantioselectivities, in dichloromethane as the solvent [47][48]. As an extension to this work, a novel chiral 2,9-disubstituted-1,10-phenanthroline 54 was prepared

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

• reaction has been extended by using a combination of 10 mol % of Cu(OTf)2, 12 mol % of 1,10-phenanthroline, and 2 equivalents of potassium phosphate, as reported by the group of Jiang (Scheme 30) [70]. Six- to eight-membered sulfur heterocycles 67 can thus be isolated from cyclic diaryl-λ3-iodanes. More

• . The same group has then developed a radical method to access the corresponding sulfones from cyclic diaryl-λ3-iodanes (Scheme 33) [73]. The reaction is catalyzed by a 1,10-phenanthroline-copper complex and affords the dibenzothiophene-5,5-dioxides 76 in moderate to high yields. The transformation has

• corresponding cyclic diaryl-λ3-iodanes, utilizing potassium thioacetate as the sulfur source, in the presence of 10 mol % of Cu(OTf)2, and 12 mol % of 1,10-phenanthroline [70]. This transformation has been successfully applied to linear diaryl-λ3-iodanes (Scheme 39). Interestingly, symmetrical and non

[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

• this synthetic approach for the synthesis of polysubstituted 1,2-diazoles (pyrazoles, indazoles). However, until 2013 when Taran’s group introduced the regioselective Cu(I)-phenanthroline catalysis [3] this method was of limited value due to the harsh reaction conditions and sometimes also due to low

• mechanism). Copper-catalyzed reaction of sydnones with terminal alkynes A substantial breakthrough in the field of 3-arylsydnone-terminal alkyne cycloaddition was achieved by Taran’s group in 2013 [3]. They developed a regioselective Cu(I)-phenanthroline-catalyzed variant of this reaction (i.e., copper

• polymeric arrangement was observed [126]. From this observations it appears that mono- or dimeric three-coordinated trigonal planar Cu(I)-acetylide-phenanthroline complex should be the reactive species during CuSAC. This idea was supported by the fact that during the reaction of 4-bromosydnones with 4