Preparation, structure, and reactivity of bicyclic benziodazole: a new hypervalent iodine heterocycle

• Akira Yoshimura,
• Michael T. Shea,
• Cody L. Makitalo,
• Melissa E. Jarvi,
• Gregory T. Rohde,
• Akio Saito,
• Mekhman S. Yusubov and
• Viktor V. Zhdankin

Beilstein J. Org. Chem. 2018, 14, 1016–1020, doi:10.3762/bjoc.14.87

• assisted coupling of carboxylic acids with alcohols or amines to afford the corresponding esters or amides in moderate to good yields. X-ray crystal structure of compound 7a. Ellipsoids are drawn to the 50% probability level. Selected bond lengths and angles: I(1)–C(1) 2.040 (4) Å; I(1)–N(1) 2.184 (4) Å; I

Methyl isocyanide as a convertible functional group for the synthesis of spirocyclic oxindole γ-lactams via post-Ugi-4CR/transamidation/cyclization in a one-pot, three-step sequence

• Amarendar Reddy Maddirala and
• Peter R. Andreana

Beilstein J. Org. Chem. 2018, 14, 875–883, doi:10.3762/bjoc.14.74

• synthesis of 5-HT6 receptor antagonist 8j [53]. Optimization conditions for the intramolecular cyclization (Scheme 3, 6→7a and 7a').a Supporting Information Supporting Information File 50: 1H and 13C NMR spectroscopic data for compounds 7a–k and 8a–j, and X-ray crystal structure details for 7a

• . Acknowledgements This work was supported by The University of Toledo. We would like to acknowledge Dr. Kristin Kirschbaum and Jennifer Gadient for providing X-ray crystal structure data.

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

• . The structure of hydantoin-fused triazolobenzodiazepine was confirmed by a X-ray crystal structure determination of 10a (Figure 3). The three-step synthesis of heterocycle-fused triazolobenzodiazepines involves the well-known Ugi 4-CR as the first step and the IAAC as the last, the mechanisms of which

• examples. X-ray crystal structure of hydantoin-fused triazolobenzodiazepine 10a. (Displacement ellipsoids are drawn at the 30% probability level.) Retrosynthetic analysis towards 2,5-diketopiperazine fused triazolobenzodiazepine. Ugi 4-CR reaction. Synthesis of diketopiperazine-fused triazolobenzodiazepine

• triazolobenzodiazepines. Supporting Information The Supporting Information features further experimental details, copies of 1H and 13C NMR spectra of compounds 5a, 6, 8, diketopiperazine-fused triazolobenzodiazepines 7 and hydantoin-fused triazolobenzodiazepines 10, and X-ray crystal structure details of 10a. Supporting

An air-stable bisboron complex: a practical bidentate Lewis acid catalyst

• Longcheng Hong,
• Sebastian Ahles,
• Andreas H. Heindl,
• Gastelle Tiétcha,
• Andrey Petrov,
• Zhenpin Lu,
• Christian Logemann and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2018, 14, 618–625, doi:10.3762/bjoc.14.48

• compound A. In that case, after removal of all the volatile components under reduced pressure, a cooling finger can be installed on the Schlenk tube for sublimation affording compound A in 55% overall yield. X-ray crystal structure analysis A single crystal of the air-stable Lewis acid B was obtained from

• greatly enhance its practicality. X-ray crystal structure analysis and UV–vis spectroscopy analysis were conducted. The tetra-coordination of the boron atoms and the highly symmetric molecular framework help to stabilize the adduct complex with respect to oxidation or hydrolysis. In addition comparative

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

• ,S-acetals 9a–c since the X-ray crystal structure of Meldrum’s acid-based N,S-acetal was reported by Wentrup [84]. In addition, the intramolecular aldol condensation of Meldrum’s acids did not occur due to the ketone structures. Table 2 displays the 1H NMR result of the sulfur ylide-like intermediate

From dipivaloylketene to tetraoxaadamantanes

• Gert Kollenz and
• Curt Wentrup

Beilstein J. Org. Chem. 2018, 14, 1–10, doi:10.3762/bjoc.14.1

• . performed the dimerization of β-ketoaldehydes with SO2Cl2 (reaction 3 in Scheme 1) [4], and the X-ray crystal structure of 1b was reported [5]. Chekalov et al. described the preparation of the tetramethyl derivative 1d by dimerization of acetylacetone induced by SiF4 (reaction 4 in Scheme 1) [6] and also

• reported the compound’s X-ray crystal structure. This transformation can also be achieved with MoOCl4 [7]. Dersch and Reichardt obtained the tetrafluoro derivative 1e in the attempted preparation of difluoromalonic dialdehyde (Scheme 1, reaction 5) [8], and Guseinov et al. reported the synthesis of the

• corresponding tetrachlorotetraoxaadamantanes together with an X-ray crystal structure of the diphenyltetrachloro derivative 1g (reaction 6 in Scheme 1) [9]. A tetraarsatetraoxaadamantane [10] also has been reported, and 13C NMR spectral characteristics of tetraoxa-, tetrathia-, and tetraselenaadamantanes have

The photodecarboxylative addition of carboxylates to phthalimides as a key-step in the synthesis of biologically active 3-arylmethylene-2,3-dihydro-1H-isoindolin-1-ones

• Ommid Anamimoghadam,
• Saira Mumtaz,
• Anke Nietsch,
• Gaetano Saya,
• Cherie A. Motti,
• Jun Wang,
• Peter C. Junk,
• Ashfaq Mahmood Qureshi and
• Michael Oelgemöller

Beilstein J. Org. Chem. 2017, 13, 2833–2841, doi:10.3762/bjoc.13.275

• -isomers was again observed (Table 4, entries 26 and 27). The solid state structure of the amination product (Z)-8a was furthermore established by X-ray crystal structure analysis (Figure 4). The phenyl group of the arylmethylene unit is positioned almost perpendicular to the isoindolinone ring on top of

Pyrene–nucleobase conjugates: synthesis, oligonucleotide binding and confocal bioimaging studies

• Artur Jabłoński,
• Yannic Fritz,
• Hans-Achim Wagenknecht,
• Rafał Czerwieniec,
• Tytus Bernaś,
• Damian Trzybiński,
• Krzysztof Woźniak and
• Konrad Kowalski

Beilstein J. Org. Chem. 2017, 13, 2521–2534, doi:10.3762/bjoc.13.249

• . An X-ray crystal structure analysis of derivative 2 shows dimers stabilized by thymine–thymine hydrogen bonds. Conjugates 2 and 3 with the carbonyl function in the linker moiety are characterized by short emission decay times and low quantum yields. The reduction of the carbonyl function in 2 and 3

Asymmetric synthesis of propargylamines as amino acid surrogates in peptidomimetics

• Matthias Wünsch,
• David Schröder,
• Tanja Fröhr,
• Lisa Teichmann,
• Sebastian Hedwig,
• Nils Janson,
• Clara Belu,
• Jasmin Simon,
• Shari Heidemeyer,
• Philipp Holtkamp,
• Jens Rudlof,
• Lennard Klemme,
• Alessa Hinzmann,
• Beate Neumann,
• Hans-Georg Stammler and
• Norbert Sewald

Beilstein J. Org. Chem. 2017, 13, 2428–2441, doi:10.3762/bjoc.13.240

• transition states TI and TII for the transfer of the methyl moiety from AlMe3 to the imino moiety. b) X-ray crystal structure analysis of the methyl transfer product 10k. Base-induced rearrangement of propargylamines bearing electron-withdrawing substituents. Base-catalyzed rearrangement of propargylamines

• (conversion of 11i to 12i). Or LiOH (3 equiv), MeOH/H2O (2:1), 0 °C, 30 min. B) UV–vis spectra of propargylamines 11 and α,β-unsaturated imines 12. C) X-ray crystal structure analysis of propargylamine 11i and α,β-unsaturated imine 12i. Preparation of N-sulfinyl propargylamines 7 with aliphatic side chains.a

• . Consequently it was not removed prior to the rearrangement experiments. Treatment of 11i and 11k with the mild base piperidine led to the formation of α,β-unsaturated sulfinylimines 12i and 12k. The structures of the rearranged products were proven unequivocally by 1H and 13C NMR spectroscopy and X-ray crystal

Solvent-free copper-catalyzed click chemistry for the synthesis of N-heterocyclic hybrids based on quinoline and 1,2,3-triazole

• Martina Tireli,
• Silvija Maračić,
• Stipe Lukin,
• Marina Juribašić Kulcsár,
• Dijana Žilić,
• Mario Cetina,
• Ivan Halasz,
• Silvana Raić-Malić and
• Krunoslav Užarević

Beilstein J. Org. Chem. 2017, 13, 2352–2363, doi:10.3762/bjoc.13.232

• after purification by column chromatography shows no traces of copper in the ESR spectrum (Supporting Information File 1, Figure S21). X-ray crystal structure analysis Single-crystal X-ray structure analysis was performed for all products. It provided clear identification of the novel triazole

• /CW spectrometer with a microwave frequency around 9.7 GHz. The measurements were performed at a modulation frequency of 100 kHz and a magnetic field modulation amplitude of 0.5 mT. The results are shown in Supporting Information File 1, Figure S21. X-ray crystal structure analysis. Single crystals of

Homologated amino acids with three vicinal fluorines positioned along the backbone: development of a stereoselective synthesis

• Raju Cheerlavancha,
• Ahmed Ahmed,
• Yun Cheuk Leung,
• Aggie Lawer,
• Qing-Quan Liu,
• Marina Cagnes,
• Hee-Chan Jang,
• Xiang-Guo Hu and
• Luke Hunter

Beilstein J. Org. Chem. 2017, 13, 2316–2325, doi:10.3762/bjoc.13.228

• intermediate J values is consistent with two major conformations of 6a existing in equilibrium (Figure 2). The first conformer (left) has an extended zigzag structure. This matches the geometry that was observed in the X-ray crystal structure for the anti,syn-trifluoroalkane 40a [17]. The second conformer

2-Methyl-2,4-pentanediol (MPD) boosts as detergent-substitute the performance of ß-barrel hybrid catalyst for phenylacetylene polymerization

• Julia Kinzel,
• Daniel F. Sauer,
• Marco Bocola,
• Marcus Arlt,
• Tayebeh Mirzaei Garakani,
• Andreas Thiel,
• Klaus Beckerle,
• Tino Polen,
• Jun Okuda and
• Ulrich Schwaneberg

Beilstein J. Org. Chem. 2017, 13, 1498–1506, doi:10.3762/bjoc.13.148

• of FhuA ΔCVFtev with MALDI–TOF mass spectrometry, two cleavage sites of the TEV protease (ENLYFQ|G) were introduced in the extracellular loop regions 7 and 8 [29]. Protease cleavage was performed as described previously [12][29]. MD simulations Simulations were based on the X-ray crystal structure of

Derivatives of the triaminoguanidinium ion, 5. Acylation of triaminoguanidines leading to symmetrical tris(acylamino)guanidines and mesoionic 1,2,4-triazolium-3-aminides

• Jan Szabo,
• Julian Greiner and
• Gerhard Maas

Beilstein J. Org. Chem. 2017, 13, 579–588, doi:10.3762/bjoc.13.57

• Information File 234: Experimental procedures, characterization data for synthesized compounds and the data for the X-ray crystal structure determinations. Acknowledgements We thank Bernhard Müller (Institute of Inorganic Chemistry II, University of Ulm) for the X-ray crystal data collection.

Synthesis of spiro[isoindole-1,5’-isoxazolidin]-3(2H)-ones as potential inhibitors of the MDM2-p53 interaction

• Salvatore V. Giofrè,
• Santa Cirmi,
• Raffaella Mancuso,
• Francesco Nicolò,
• Giuseppe Lanza,
• Laura Legnani,
• Agata Campisi,
• Maria A. Chiacchio,
• Michele Navarra,
• Bartolo Gabriele and
• Roberto Romeo

Beilstein J. Org. Chem. 2016, 12, 2793–2807, doi:10.3762/bjoc.12.278

• silica gel 0.040–0.063 mm. X-ray crystal structure determination of compound 6a was performed at room temperature on a suitable single crystal, obtained by recrystallization from ether/dichloromethane 2:1, by a Bruker AXS K Apex II CCD diffractometer with Mo Kα radiation (λ = 0.71073 Å). The structure

• MDM2-p53 interaction inhibitors. Retrosynthetic route to spiro[isoindole-1,5-isoxazolidin]-3(2H)-ones 3. Selected NOESY observed for compounds 6a and 7a. ORTEP drawing of the X-ray crystal structure of 7a showing the model atomic numbering scheme (C10 and C9 correspond to the chiral centres C1 and C4

Et₃B-mediated and palladium-catalyzed direct allylation of β-dicarbonyl compounds with Morita–Baylis–Hillman alcohols

• Ahlem Abidi,
• Yosra Oueslati and
• Farhat Rezgui

Beilstein J. Org. Chem. 2016, 12, 2402–2409, doi:10.3762/bjoc.12.234

• chromatography over silica gel (gradient: petroleum ether/ether = 4:1) to give the pure allylated products 3–8 in moderate to good yields. Cyclic and acyclic MBH alcohols. X-ray crystal structure of tricyclic compound 6j. Proposed catalytic cycle involving palladium catalysis for Et3B-promoted allylation of

Superelectrophilic activation of 5-hydroxymethylfurfural and 2,5-diformylfuran: organic synthesis based on biomass-derived products

• Dmitry S. Ryabukhin,
• Dmitry N. Zakusilo,
• Mikhail O. Kompanets,
• Anton A.Tarakanov,
• Irina A. Boyarskaya,
• Tatiana O. Artamonova,
• Mikhail A. Khohodorkovskiy,
• Iosyp O. Opeida and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2016, 12, 2125–2135, doi:10.3762/bjoc.12.202

• -glucose or D-fructose followed by oxidation to 2,5-DFF. X-ray crystal structure of compounds 5a (a), and 5c (b) (ORTEP diagrams, ellipsoid contour of probability levels is 50%, CCDC reference numbers 5a: 1483523, 5c: 1483524). Protonation of 5-HMF (1a) and 2,5-DFF (2) leading to cationic species A, B, C

Synthesis and properties of fluorescent 4′-azulenyl-functionalized 2,2′:6′,2″-terpyridines

• Adrian E. Ion,
• Liliana Cristian,
• Mariana Voicescu,
• Masroor Bangesh,
• Augustin M. Madalan,
• Daniela Bala,
• Constantin Mihailciuc and
• Simona Nica

Beilstein J. Org. Chem. 2016, 12, 1812–1825, doi:10.3762/bjoc.12.171

• can influence the emission behavior and it may be changed from dominant S2→S0 fluorescence to either dual fluorescence or to dominant S1→S0 fluorescence. Theoretical calculations Methods The geometries of 4a and 4b with initial atomic coordinates taken from X-ray crystal structure were optimized with

Catalytic Chan–Lam coupling using a ‘tube-in-tube’ reactor to deliver molecular oxygen as an oxidant

• Carl J. Mallia,
• Paul M. Burton,
• Alexander M. R. Smith,
• Gary C. Walter and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2016, 12, 1598–1607, doi:10.3762/bjoc.12.156

• being detected. The regioselectivity of the 1,3-disubsituted pyrazoles was confirmed by NOESY NMR experiments (30, 33 and 35, Figures 4–6) as well as comparison to known published data. In addition, an X-ray crystal structure for compound 33 was obtained and the connectivity confirmed. It was noted that

The hydrolysis of geminal ethers: a kinetic appraisal of orthoesters and ketals

• Sonia L. Repetto,
• James F. Costello,
• Craig P. Butts,
• Joseph K. W. Lam and
• Norman M. Ratcliffe

Beilstein J. Org. Chem. 2016, 12, 1467–1475, doi:10.3762/bjoc.12.143

• rates of hydrolysis for six-membered 15 and 8 could be explained with the kinetic anomeric effect. Consistent with this, the X-ray crystal structure of an analogous yet conformationally constrained bicyclic orthoester possesses an unusually elongated axial C─O bond (Figure 2a), which undergoes

Stereoselective synthesis of tricyclic compounds by intramolecular palladium-catalyzed addition of aryl iodides to carbonyl groups

• Jakub Saadi,
• Christoph Bentz,
• Kai Redies,
• Dieter Lentz,
• Reinhold Zimmer and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2016, 12, 1236–1242, doi:10.3762/bjoc.12.118

• -catalyzed cyclization process that stereoselectively led to bi- and tricyclic compounds in moderate to excellent yields. Four X-ray crystal structure analyses unequivocally defined the structure of crucial cyclization products. The relative configuration of the precursor compounds is essentially transferred

• with those discussed below, where X-ray crystal structure analyses unequivocally confirmed the relative configurations of cyclization products. With the cyclic ketones in part considerably higher yields of tricyclic products could be obtained (Schemes 4–6). The cyclopentanone derivative 3 (Scheme 4

• determined by an X-ray crystal structure analysis of the corresponding p-nitrobenzoate 12a obtained by esterification of the tertiary alcohol under standard conditions (Scheme 4, Figure 1) [13]. The configuration of the second product 11b is only tentatively assigned as depicted since the available data do

Synthesis of 2-oxindoles via 'transition-metal-free' intramolecular dehydrogenative coupling (IDC) of sp² C–H and sp³ C–H bonds

• Nivesh Kumar,
• Santanu Ghosh,
• Subhajit Bhunia and
• Alakesh Bisai

Beilstein J. Org. Chem. 2016, 12, 1153–1169, doi:10.3762/bjoc.12.111

• efficient one-pot formation of three consecutive carbon–carbon bonds. X-ray crystal structure determination of (±)-19b proved the outcome of the reaction unambiguously. It was noteworthy to observe Pd-catalyzed highly enantio-, chemo-, and diastereoselective double decarboxylative allylations on dimeric β-N

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

• for chiral sulfoxide synthesis. (a) General synthetic sequence to access enyne bicycloisomerization substrates (b) Synthesis of 2-cyclopropylprop-2-en-1-ol using a modified Suzuki coupling reaction developed by Soderquist. Deprotection of [3.1.0] bicycles and X-ray crystal structure of 76. ProPhenol

Iodine-mediated synthesis of 3-acylbenzothiadiazine 1,1-dioxides

• Long-Yi Xi,
• Ruo-Yi Zhang,
• Lei Shi,
• Shan-Yong Chen and
• Xiao-Qi Yu

Beilstein J. Org. Chem. 2016, 12, 1072–1078, doi:10.3762/bjoc.12.101

• over Na2SO4 (anhydrous), concentrated in vacuum, and the resulting residue was purified by column chromatography on silica gel with EtOAc/petroleum (1:4) to afford the product. X-ray crystal structure of 4b (CCDC 1444753). Selected benzothiadaiazine 1,1-dioxides with potent biological activities. Scope

Muraymycin nucleoside-peptide antibiotics: uridine-derived natural products as lead structures for the development of novel antibacterial agents

• Daniel Wiegmann,
• Stefan Koppermann,
• Marius Wirth,
• Giuliana Niro,
• Kristin Leyerer and
• Christian Ducho

Beilstein J. Org. Chem. 2016, 12, 769–795, doi:10.3762/bjoc.12.77

• phosphate. This was speculated to be followed by a one-step nucleophilic attack of the C55-alkyl phosphate at the UDP-MurNAc-pentapeptide (Figure 6B) [69]. In 2013, Lee et al. reported an X-ray crystal structure (3.3 Å resolution) of MraY from Aquifex aeolicus (MraYAA) as the first structure of a member of

Pyridylidene ligand facilitates gold-catalyzed oxidative C–H arylation of heterocycles

• Kazuhiro Hata,
• Hideto Ito,
• Yasutomo Segawa and
• Kenichiro Itami

Beilstein J. Org. Chem. 2015, 11, 2737–2746, doi:10.3762/bjoc.11.295

• PhICl2 (see Experimental section and Supporting Information File 1 for details) [114]. The X-ray crystallographic analysis was successfully accomplished with a colorless single crystal of AuCl3(PyC), which was recrystallized from nitrobenzene and pentane (Figure 3) [115]. The X-ray crystal structure