Synergistic approach to polycycles through Suzuki–Miyaura cross coupling and metathesis as key steps

• Sambasivarao Kotha,
• Milind Meshram and
• Chandravathi Chakkapalli

Beilstein J. Org. Chem. 2018, 14, 2468–2481, doi:10.3762/bjoc.14.223

• %) was prepared via a SM coupling of the dibromo compound 112 with 4-formylphenylboronic acid (100). Treatment of dialdehyde 113 with allyl bromide (28) in the presence of indium powder furnished the RCM precursor 114. Under the influence of the G-II catalyst 2 RCM of diolefinic compound 114 was realized

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

• -decorated TTF-rotaxanes was achieved by Gao and co-workers [95]. They deposited a thin-film of bistable donor–acceptor rotaxanes on an indium tin oxide (ITO)-coated substrate. A clean electrochemical switching on the substrate was observed with current–voltage curves showing a clear memory effect. The

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

Cross-coupling of dissimilar ketone enolates via enolonium species to afford non-symmetrical 1,4-diketones

• Keshaba N. Parida,
• Gulab K. Pathe,
• Shimon Maksymenko and
• Alex M. Szpilman

Beilstein J. Org. Chem. 2018, 14, 992–997, doi:10.3762/bjoc.14.84

• . Recently, Loh reported the palladium-catalyzed coupling of an acid chloride with premade isolable indium homoenolates (In(CH2CHRC=OR')2), 1.2 equiv relative to the acid chloride) to give the corresponding 1,4-diketones [5]. Yet the direct coupling of two enolates is inarguably the shortest and most direct

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

• ’ = isopropyl, 42). The reactions were carried out with various metal catalysts in acetic acid and acetonitrile solvents but reactions carried in acetic acid in presence of silica gel impregnated with indium trichloride provided the best results. Júnior et al. [53] also used N,N-dimethylpyrazoylimines 42 with N

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

• -5,10,15,20-tetraphenylporphyrins with meso-substituted dipyrromethanes. Hybrid compounds have been characterized by 1H NMR, 13C NMR, 2D NMR, UV–vis absorption and fluorescence spectroscopy. Keywords: corrole; hybrid compounds; indium(III) chloride; porphyrin; porphyrinoids; Introduction Porphyrins and

Reagent-controlled regiodivergent intermolecular cyclization of 2-aminobenzothiazoles with β-ketoesters and β-ketoamides

• Irwan Iskandar Roslan,
• Kian-Hong Ng,
• Gaik-Khuan Chuah and
• Stephan Jaenicke

Beilstein J. Org. Chem. 2017, 13, 2739–2750, doi:10.3762/bjoc.13.270

• , In(OTf)3, results in the regioselective nucleophilic attack at both carbonyl groups forming benzo[4,5]thiazolo[3,2-a]pyrimidin-4-ones instead. Keywords: cyclization; fused-ring systems; indium; radical; regiodivergent; Introduction β-Ketoesters are versatile substrates frequently used in

• (2a, 162 μL, 1.5 mmol) and indium(III) trifluoromethanesulfonate (56 mg, 0.1 mmol) in 1.5 mL of toluene. After stirring at 100 °C for 16 h, the reaction was diluted with water and extracted with EtOAc (15 mL × 5). The combined organic layers were washed with brine and dried with anhydrous Na2SO4

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

• synthesis. We have already achieved the metal-catalyzed and acid-mediated cationic cyclization of 1,1-difluoro-1-alkenes. In the former case, we reported the palladium [6][7][8][9][10], indium [10][11][12][13], and silver-catalyzed construction of ring-fluorinated carbocycles and heterocycles [14]. In the

A concise flow synthesis of indole-3-carboxylic ester and its derivatisation to an auxin mimic

• Marcus Baumann,
• Ian R. Baxendale and
• Fabien Deplante

Beilstein J. Org. Chem. 2017, 13, 2549–2560, doi:10.3762/bjoc.13.251

• incomplete reduction were obtained in greater amounts as the flow rate was further increased along with an increasing proportion of the hydroxyaminoindole 15. This correlates with previous literature findings employing catalysed hydrogenation [22][23][24][25][26] or stoichiometric metal (zinc or indium

Phosphonic acid: preparation and applications

• Charlotte M. Sevrain,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2017, 13, 2186–2213, doi:10.3762/bjoc.13.219

• 14, Figure 4), was assessed to complex indium [86] or terbium [87] with the aim to develop bone targeting and dosimetry. It was also employed to complex 89Y and applied as pH sensitive NMR probe [88], or as organic precursor of crystalline manganese, nickel [89] or lanthanide-containing hybrid

Main group mechanochemistry

• Agota A. Gečiauskaitė and
• Felipe García

Beilstein J. Org. Chem. 2017, 13, 2068–2077, doi:10.3762/bjoc.13.204

• methods (see Scheme 3).· Also noteworthy is the multistep solvent-free mechanochemical route to indium(III) complexes featuring aryl bis(imino)acenaphthene (Ar-BIAN) ligands [84]. Ar-BIAN ligands are versatile π-acceptors and have been widely employed for catalysis. These ligands are typically synthesised

• produce the desired Ar-BIAN ligands 2 and 3, respectively, in good yields (see Scheme 4). Here, mechanochemistry bypasses the use of templating agent transition metals, shortening the synthetic route and reducing its environmental impact. Their respective indium(III) BIAN complexes 4 and 5 were also

• ) (Cp′ = C5Me4(n-Pr)). Mechanochemical synthesis of the Ar-BIAN ligands and indium(III) complexes (top). One-pot synthesis of an indium complex (bottom). Synthesis of germanes from germanium (Ge) or germanium oxide (GeO2). Ball-milling nucleophilic substitution reactions to produce acyclic and cyclic

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

• first palladium-catalyzed arylation of thiols was reported by Migita and co-workers in 1980 [5], and soon after Cristau and co-workers developed a nickel-catalyzed route for C–S cross-coupling reactions [6]. Other metals such as copper [7], cobalt [8], iron [9], rhodium [10], manganese [11], indium [12

Synthesis of ribavirin 2’-Me-C-nucleoside analogues

• Fanny Cosson,
• Aline Faroux,
• Jean-Pierre Baltaze,
• Jonathan Farjon,
• Régis Guillot,
• Jacques Uziel and
• Nadège Lubin-Germain

Beilstein J. Org. Chem. 2017, 13, 755–761, doi:10.3762/bjoc.13.74

• carbon atom in the 2’-position are an indium-mediated alkynylation and a 1,3-dipolar cyclization. Keywords: alkynylation; antiviral; cancer; C-nucleosides; ribavirin; Introduction The triazole nucleoside ribavirin (RBV, Figure 1) is used for the treatment of a number of viral infections and may be

• of antivirals due to their stability in biological fluids and their bioavailability. Some years ago, we described an approach leading to the C-ribosylated analogue 1 of ribavirin (Figure 2) with the key-steps of the synthesis being an indium-mediated alkynylation of a ribose derivative followed by

• commercially available 2-C-methyl-1,2,3,5-tetra-O-benzoyl-β-D-ribofuranose (4) as shown in Scheme 1. Debenzoylation of 4 followed by selective protection led to derivative 5, which was submitted to the indium-mediated alkynylation reaction affording the alkynyl riboside 6 with the same β-anomeric selectivity

Effect of the ortho-hydroxy group of salicylaldehyde in the A³ coupling reaction: A metal-catalyst-free synthesis of propargylamine

• Sujit Ghosh,
• Kinkar Biswas,
• Suchandra Bhattacharya,
• Pranab Ghosh and
• Basudeb Basu

Beilstein J. Org. Chem. 2017, 13, 552–557, doi:10.3762/bjoc.13.53

• ], mercury [26], cobalt [27], iridium [28], ruthenium [29], indium [30] etc. Other methods towards the synthesis of propargylamine include: alkynylation of imine [31][32][33], enamine [34], and Csp³–H bonds adjacent to N-atoms [35][36]. In the A3 coupling, the role of the metal catalyst is believed to

Synthesis of 1-indanones with a broad range of biological activity

• Marika Turek,
• Dorota Szczęsna,
• Marek Koprowski and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

• rhodium(II) complex 220 followed by the carboxylic methyl ester hydrolysis/decarboxylation in DMSO/H2O at 120 °C with up to 72% enantiomeric excess (Scheme 60) [89]. 1.7 From epoxides and cyclopropanes The chalcone epoxides 221 ring opening catalyzed by indium(III) chloride, followed by a intramolecular

Conjugate addition–enantioselective protonation reactions

• James P. Phelan and
• Jonathan A. Ellman

Beilstein J. Org. Chem. 2016, 12, 1203–1228, doi:10.3762/bjoc.12.116

• the major enantiomer was not defined (Scheme 3) [18]. Indium was used to initiate the addition of a perfluorobutyl radical to α-aminoacrylate 11 followed by hydrogen atom transfer to the resulting α-amino α-ester radical from (R,R)-12. Enantioenriched tryptophan derivatives are useful building blocks

Chiral cyclopentadienylruthenium sulfoxide catalysts for asymmetric redox bicycloisomerization

• Barry M. Trost,
• Michael C. Ryan and
• Meera Rao

Beilstein J. Org. Chem. 2016, 12, 1136–1152, doi:10.3762/bjoc.12.110

• [41] (Figure 1a). The proposed mechanism of this fascinating reaction involves chloride abstraction of the ruthenium catalyst by indium(III) triflate and phosphine ligand dissociation. The propargyl alcohol then coordinates to the now coordinatively unsaturated cyclopentadienylruthenium (CpRu

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

• . The stereogenetic outcome could be explained by the configuration of oxametallacycle I, in which two bulky phenyl rings are trans orientated to each other. In 2014, Yoda and co-workers developed an indium/PyBox complex-catalyzed enantioselective allylation of isatins with stannylated reagents

Scope and mechanism of the highly stereoselective metal-mediated domino aldol reactions of enolates with aldehydes

• M. Emin Cinar,
• Bernward Engelen,
• Martin Panthöfer,
• Hans-Jörg Deiseroth,
• Jens Schlirf and
• Michael Schmittel

Beilstein J. Org. Chem. 2016, 12, 813–824, doi:10.3762/bjoc.12.80

• on the metals. While the yield was decreased with zirconium, it increased both with aluminum and indium. In the latter case, >99% yield was obtained. In the same manner the influence of the amount of aldehyde was examined. As can be seen from the data in Table 3 the ratio of 5a to 6a decreases

• incorporation of the two enantiomers of 7h and they are held together by hydrogen bonds (intramolecular: 1.90 Å, intermolecular: 1.93 Å) (Figure 2). Various aldehydes were also probed in the domino aldol reaction with the indium enolate of butyrophenone (1f, Scheme 4). Reactions involving 2-furfural

• core potential (ECP) on hexa-coordinate indium [51] as implemented in Gaussian 09 owing to the predicted good results in our earlier work [30]. The remaining coordination sites of indium were occupied by two THF molecules. The minima and transition states of the calculated structures were verified by

Synthesis and photophysical characteristics of polyfluorene polyrotaxanes

• Aurica Farcas,
• Giulia Tregnago,
• Ana-Maria Resmerita,
• Pierre-Henri Aubert and
• Franco Cacialli

Beilstein J. Org. Chem. 2015, 11, 2677–2688, doi:10.3762/bjoc.11.288

• reported [20]. Furthermore, these results suggest that the reduction process of 3·TM-βCD displays a semi-reversible behavior. The HOMO/LUMO energy levels in combination with the electronic potentials of the anodic indium tin oxide (ITO) glass substrate (−4.75 eV) and cathodic aluminum (−2.2 eV), prove that

Inclusion complexes of 2-methoxyestradiol with dimethylated and permethylated β-cyclodextrins: models for cyclodextrin–steroid interaction

• Mino R. Caira,
• Susan A. Bourne,
• Halima Samsodien and
• Vincent J. Smith

Beilstein J. Org. Chem. 2015, 11, 2616–2630, doi:10.3762/bjoc.11.281

• Nikon SMZ-10 stereoscopic microscope. The Soft Imaging system, analySIS [31] was used to process the images. For TGA a Mettler Toledo TGA/SDTA851e instrument was employed with a nitrogen gas purge (flow rate 30 cm3/min). Indium (mp 156.6 °C) and aluminium (mp 660.3 °C) were used for all calibrations

• of fusion of indium (156.6 °C) and zinc (419.5 °C). The heat flow calibration was based on the value of ΔH of fusion of indium (28.62 J/g). Samples in the form of fine powders (mass range 2–5 mg) were sealed in crimped, vented aluminium pans and were heated at 10 K/min, with a sealed, empty pan as

Easy access to heterobimetallic complexes for medical imaging applications via microwave-enhanced cycloaddition

• Nicolas Desbois,
• Sandrine Pacquelet,
• Adrien Dubois,
• Clément Michelin and
• Claude P. Gros

Beilstein J. Org. Chem. 2015, 11, 2202–2208, doi:10.3762/bjoc.11.239

• applications [24]. Indium-111. One major isotope used within DOTA–SPECT agents is 111In (displaying a half-live of 67 hours). It should be noted that the well-established 111In–DOTA is in vivo robust [25] and many articles have been reported in the literature highly supporting the potential convenient utility

• of radiolabeled 111In–NOTA [26]. Unlike the corrole macrocycle, indium(III) porphyrins can be prepared [27]. We wish to report herein (Scheme 1) the convenient synthesis of various multimodal ligands. Those complexes, incorporating one porphyrin or one corrole moiety on one side and one DOTA or NOTA

• solution of GaCl3 in pyridine and then refluxed for 1.5 h as previously described [28]. Corroles 8a and 8b were prepared and characterized by 1H NMR, HRMS and UV–vis absorption spectroscopy. Different metal ions were introduced inside the porphyrin core 2, namely copper, gallium, indium and manganese. For

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• and an RCM as key steps. In this regard, the α,α'-dibromo-m-xylene (136) was treated with arylboronic acid 180, to give the dialdehyde 181 which on reaction with indium-mediated Grignard addition reaction gave diolefin 182. Later RCM of diolefin 182 delivered cyclophane 183. Subsequent oxidation of

Inclusion of trans-resveratrol in methylated cyclodextrins: synthesis and solid-state structures

• Lee Trollope,
• Dyanne L. Cruickshank,
• Terence Noonan,
• Susan A. Bourne,
• Milena Sorrenti,
• Laura Catenacci and
• Mino R. Caira

Beilstein J. Org. Chem. 2014, 10, 3136–3151, doi:10.3762/bjoc.10.331

• was previously calibrated with indium as standard reference. Measurements were carried out at least in triplicate. For co-precipitated, crystalline products, traces were recorded on a DSC-Q200 differential scanning calorimeter with samples in closed aluminium pans heated at 10 K min−1 and dry nitrogen

• Toledo, Novate Milanese, MI, Italy) TGA with simultaneous DSC (TGA/DSC1) on 4–6 mg samples in alumina crucibles with lid [β = 10 K min−1, nitrogen air atmosphere (flux 50 mL min−1), 30–350 °C temperature range]. The instrument was previously calibrated with indium as standard reference and measurements

One-pot functionalisation of N-substituted tetrahydroisoquinolines by photooxidation and tunable organometallic trapping of iminium intermediates

• Joshua P. Barham,
• Matthew P. John and
• John A. Murphy

Beilstein J. Org. Chem. 2014, 10, 2981–2988, doi:10.3762/bjoc.10.316

• albeit in lower yield (68%). Murthy and Blechert and their respective co-workers reported allylation of THIQs under aerobic conditions using allyltrialkylstannanes [12][16] (Blechert’s studies also included success with allylboron reagents). Whilst our reactions are carried out under N2, the indium metal

• used, allylindium reagents generated and indium trihalide salt byproducts are non-toxic [43]. Our conditions benefit from the absence of amide side-products typically effected by peroxide intermediates in aerobic photoactivation of THIQs [16][22] and so our methodology serves to complement existing