Methylpalladium complexes with pyrimidine-functionalized N-heterocyclic carbene ligands

• Dirk Meyer and
• Thomas Strassner

Beilstein J. Org. Chem. 2016, 12, 1557–1565, doi:10.3762/bjoc.12.150

• anomalous dispersion corrections for the non-hydrogen atoms were taken from the International Tables for Crystallography [77]. All calculations were performed with the SHELXL-97 [78] package and the programs COLLECT [79], DIRAX [80], EVALCCD [81], SIR-92 [82], SADABS [76], ORTEP III [83] and PLATON [84

Beta-hydroxyphosphonate ribonucleoside analogues derived from 4-substituted-1,2,3-triazoles as IMP/GMP mimics: synthesis and biological evaluation

• Tai Nguyen Van,
• Audrey Hospital,
• Corinne Lionne,
• Lars P. Jordheim,
• Charles Dumontet,
• Christian Périgaud,
• Laurent Chaloin and
• Suzanne Peyrottes

Beilstein J. Org. Chem. 2016, 12, 1476–1486, doi:10.3762/bjoc.12.144

• potential binding sites have been described in the literature [17][18]. According to the X-ray crystallography, kinetics and mutagenesis studies, four effectors have been identified for binding in the effector site 1. The activation of the site 2 is more questionable as solid data is still required to

Stereodynamic tetrahydrobiisoindole “NU-BIPHEP(O)”s: functionalization, rotational barriers and non-covalent interactions

• Golo Storch,
• Sebastian Pallmann,
• Frank Rominger and
• Oliver Trapp

Beilstein J. Org. Chem. 2016, 12, 1453–1458, doi:10.3762/bjoc.12.141

• phase for seven days. Investigation of “NU-BIPHEP(O)” 1b. A) Solid-state structure determined by X-ray crystallography. Hydrogen atoms and methanol solvent molecules are omitted for clarity. B) Interaction studies in solution with soluble Okamoto phase 4 by 31P{1H} NMR spectroscopy. Black: spectrum of

Synthesis of ferrocenyl-substituted 1,3-dithiolanes via [3 + 2]-cycloadditions of ferrocenyl hetaryl thioketones with thiocarbonyl S-methanides

• Grzegorz Mlostoń,
• Róża Hamera-Fałdyga,
• Anthony Linden and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2016, 12, 1421–1427, doi:10.3762/bjoc.12.136

• , bearing a phenyl group, the absorption of the CH2 group was found at 31.2 ppm. The structures of the ferrocenyl-substituted 1,3-dithiolanes 5b, 5e, 5f, and 5g have been established unambiguously by X-ray crystallography (see Figure 1 for 5b and 5f). The space group of 5b is non-centrosymmetric with a

Ring-whizzing in polyene-PtL₂ complexes revisited

• Oluwakemi A. Oloba-Whenu,
• Thomas A. Albright and
• Chirine Soubra-Ghaoui

Beilstein J. Org. Chem. 2016, 12, 1410–1420, doi:10.3762/bjoc.12.135

• the uncoordinated portion of the polyene having alternating C–C bond lengths of ≈1.45 and 1.35 Å. This is in fact the structure of an analogous Ni complex as determined by X-ray crystallography [56]. The haptotropic rearrangement of 28 to 30 does not permute all of the carbon atoms in the COT ring

Selective bromochlorination of a homoallylic alcohol for the total synthesis of (−)-anverene

• Frederick J. Seidl and
• Noah Z. Burns

Beilstein J. Org. Chem. 2016, 12, 1361–1365, doi:10.3762/bjoc.12.129

• (−)-anverene (1, see below), the absolute configuration of which was determined by the isolation chemists on natural material by X-ray crystallography [10]. Interestingly, using the same enantiomer of ligand, the bromochlorides derived from prenol and homoprenol (5) have the same absolute configuration. This

Reactivity studies of pincer bis-protic N-heterocyclic carbene complexes of platinum and palladium under basic conditions

• David C. Marelius,
• Curtis E. Moore,
• Arnold L. Rheingold and
• Douglas B. Grotjahn

Beilstein J. Org. Chem. 2016, 12, 1334–1339, doi:10.3762/bjoc.12.126

• -Pt and 8-Pt as LiCl-imidazolyl adducts. All attempts at characterization by crystallography have been unsuccessful due to the very water-sensitive nature of 7 and 8. Therefore, the environment of the lithium and chloride is unknown but it is assumed to be similar to that of 3, which is formed under

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

• lithium aluminum hydride in excellent yield. The absolute configuration of the [3.1.0] pyrrolidines was assigned by analogy to 76, which was determined to be (R,R) by single crystal X-ray crystallography. Mechanistic studies After having successfully developed this synthetic methodology, a few questions

• : Experimental details and NMR data of new catalysts. Supporting Information File 116: X-ray crystallography data for 76. Acknowledgements We would like to thank the NSF for their generous support (NSF-CHE-1360634).

Modular synthesis of the pyrimidine core of the manzacidins by divergent Tsuji–Trost coupling

• Sebastian Bretzke,
• Stephan Scheeff,
• Felicitas Vollmeyer,
• Friederike Eberhagen,
• Frank Rominger and
• Dirk Menche

Beilstein J. Org. Chem. 2016, 12, 1111–1121, doi:10.3762/bjoc.12.107

• obtained (24%) could be readily removed by column chromatography. The configuration of 31 was initially assigned by Mosher ester analysis of the free amine 36 (Scheme 6) and finally proven in an indirect manner by an X-ray crystallography of the minor diastereomer 32. Within the course of this study also

• place even without an additional base, which shows the strong influence of the amine protective group on this type of condensation. Importantly, at this stage, the structure of 39 was fully confirmed by X-ray crystallography. As shown in Figure 2, this urea derivative is present as an unsymmetrical

Towards the total synthesis of keramaphidin B

• Pavol Jakubec,
• Alistair J. M. Farley and
• Darren J. Dixon

Beilstein J. Org. Chem. 2016, 12, 1096–1100, doi:10.3762/bjoc.12.104

• the Oxford Chemical Crystallography Service for use of the instrumentation. X-ray crystallographic data have been deposited in the Cambridge Crystallographic Data Centre database (http://www.ccdc.cam.ac.uk/) under accession code 1481419.

Cationic Pd(II)-catalyzed C–H activation/cross-coupling reactions at room temperature: synthetic and mechanistic studies

• Takashi Nishikata,
• Alexander R. Abela,
• Shenlin Huang and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2016, 12, 1040–1064, doi:10.3762/bjoc.12.99

• gave excellent selectivity at room temperature (Scheme 5). When this substrate was subjected to optimized conditions for the boronic acid C–H coupling, the corresponding singly ortho-arylated product was obtained in 97% yield solely as the 2-aryl isomer, as confirmed by 1H NMR and X-ray crystallography

• herbicide boscalid. Mechanistic investigations revealed that a dicationic Pd(II) complex reacts readily with an arylurea to rapidly produce a mono-cationic palladacycle at room temperature, and this likely, catalytically competent species has been characterized by X-ray crystallography. Experiments revealed

Separation and identification of indene–C₇₀ bisadduct isomers

• Bolong Zhang,
• Jegadesan Subbiah,
• David J. Jones and
• Wallace W. H. Wong

Beilstein J. Org. Chem. 2016, 12, 903–911, doi:10.3762/bjoc.12.88

• device performance. In a previous communication [9], an isomer of IC70BA was obtained by chromatographic separation using both flash chromatography and high pressure liquid chromatography (HPLC). X-ray crystallography revealed that this sample contained the 2 o’clock-B isomer (Figure 2b). This material

Bi- and trinuclear copper(I) complexes of 1,2,3-triazole-tethered NHC ligands: synthesis, structure, and catalytic properties

• Shaojin Gu,
• Jiehao Du,
• Jingjing Huang,
• Huan Xia,
• Ling Yang,
• Weilin Xu and
• Chunxin Lu

Beilstein J. Org. Chem. 2016, 12, 863–873, doi:10.3762/bjoc.12.85

• fully characterized by NMR, elemental analysis (EA), and X-ray crystallography. In particular, [Cu2(L2)2](PF6)2 (3) and [Cu2(L3)2](PF6)2 (4) were dinuclear copper complexes. Complexes [Cu3(L4)2](PF6)3 (5) and [Cu3(L5)2](PF6)3 (6) consist of a triangular Cu3 core. These structures vary depending on the

• copper–NHC complexes are stable in air. They were fully characterized by NMR, elemental analysis (EA), and X-ray crystallography. The generation of these copper–NHC complexes were confirmed by the absence of the 1H NMR resonance signal of the acidic imidazolium protons between 10.04 and 10.89 ppm. The 1H

• -heterocyclic carbene ligands have been prepared via simple reactions of imidazolium salts with copper powder in good yields. These complexes have been fully characterized by NMR, elemental analysis (EA) and X-ray crystallography. Fine adjustment of the structure of the ligand can lead to different structures

A modular approach to neutral P,N-ligands: synthesis and coordination chemistry

• Vladislav Vasilenko,
• Torsten Roth,
• Clemens K. Blasius,
• Sebastian N. Intorp,
• Hubert Wadepohl and
• Lutz H. Gade

Beilstein J. Org. Chem. 2016, 12, 846–853, doi:10.3762/bjoc.12.83

• neutral κ2-P,N-ligands comprising an imine and a phosphine binding site. These ligands were reacted with rhodium, iridium and palladium metal precursors and the structures of the resulting complexes were elucidated by means of X-ray crystallography. We observed that subtle changes of the ligand backbone

Natural products from microbes associated with insects

• Christine Beemelmanns,
• Huijuan Guo,
• Maja Rischer and
• Michael Poulsen

Beilstein J. Org. Chem. 2016, 12, 314–327, doi:10.3762/bjoc.12.34

• geldanamycin analog with an unusual side chain modification (20) were isolated (Figure 6) [96]. The structure of 18 was elucidated using a combination of NMR spectroscopy, X-ray crystallography and additional quantum chemical NMR calculations. Bacterial mutualists Streptomyces and other Actinobacteria are well

Copper-catalyzed intermolecular oxyamination of olefins using carboxylic acids and O-benzoylhydroxylamines

• Brett N. Hemric and
• Qiu Wang

Beilstein J. Org. Chem. 2016, 12, 22–28, doi:10.3762/bjoc.12.4

• this work and the fellowships from the Burroughs Wellcome Endowment (B.N.H.). We also thank Dr. George Dubay for assistance with HRMS experiments and Dr. Roger Sommer for assistance with X-ray crystallography.

Selectively fluorinated cyclohexane building blocks: Derivatives of carbonylated all-cis-3-phenyl-1,2,4,5-tetrafluorocyclohexane

• Mohammed Salah Ayoup,
• David B. Cordes,
• Alexandra M. Z. Slawin and
• David O'Hagan

Beilstein J. Org. Chem. 2015, 11, 2671–2676, doi:10.3762/bjoc.11.287

• a mixture of stilbene isomers 16. Direct hydrogenation of the mixture afford dihydrostilbene 17 as a crystalline solid, a structure which was confirmed by X-ray crystallography and is shown in the inset in Scheme 3. Aldehyde 15 could also be converted to styrene 18 in good yield using the Simmons

Comparison of the catalytic activity for the Suzuki–Miyaura reaction of (η⁵-Cp)Pd(IPr)Cl with (η³-cinnamyl)Pd(IPr)(Cl) and (η³-1-t-Bu-indenyl)Pd(IPr)(Cl)

• Patrick R. Melvin,
• Nilay Hazari,
• Hannah M. C. Lant,
• Ian L. Peczak and
• Hemali P. Shah

Beilstein J. Org. Chem. 2015, 11, 2476–2486, doi:10.3762/bjoc.11.269

• one bridging allyl or indenyl ligand [13]. CpDim was characterized by NMR spectroscopy and X-ray crystallography (see Figure 4). The binding of the bridging Cp ligand is similar to that observed in other Pd(I) dimers supported by a bridging Cp or indenyl ligand [23][24][25][26][27][28][29][30][31][32

• crystallography X-ray diffraction experiments were carried out on a Rigaku MicroMax-007HF diffractometer coupled to a Saturn994+ CCD detector with Cu Kα radiation (λ = 1.54178 Å) at −180 °C. The crystals were mounted on MiTeGen polyimide loops with immersion oil. The data frames were processed using Rigaku

• an NSF Graduate Research Fellow. NH is a fellow of the Alfred P. Sloan Foundation and a Camille and Henry-Dreyfus Foundation Teacher Scholar. We thank Dr. Brandon Mercado for assistance with X-ray crystallography.

Co-solvation effect on the binding mode of the α-mangostin/β-cyclodextrin inclusion complex

• Chompoonut Rungnim,
• Sarunya Phunpee,
• Manaschai Kunaseth,
• Supawadee Namuangruk,
• Kanin Rungsardthong,
• Thanyada Rungrotmongkol and
• Uracha Ruktanonchai

Beilstein J. Org. Chem. 2015, 11, 2306–2317, doi:10.3762/bjoc.11.251

• databank (3C6G), while the α-MGS structure was extracted from the International Union of Crystallography (KP2293) database, see Figure 1. According to the ChemAxon method [25][26][27], the calculated pKa of three hydroxy groups are 7.4 (O6), 7.8 (O3), and 8.2 (O5). For that reason, the α-mangostin was

2-Hetaryl-1,3-tropolones based on five-membered nitrogen heterocycles: synthesis, structure and properties

• Yury A. Sayapin,
• Inna O. Tupaeva,
• Alexandra A. Kolodina,
• Eugeny A. Gusakov,
• Vitaly N. Komissarov,
• Igor V. Dorogan,
• Nadezhda I. Makarova,
• Anatoly V. Metelitsa,
• Valery V. Tkachev,
• Sergey M. Aldoshin and
• Vladimir I. Minkin

Beilstein J. Org. Chem. 2015, 11, 2179–2188, doi:10.3762/bjoc.11.236

• the three representative compounds were determined by X-ray crystallography. In crystal and (as shown by the DFT PBE0/6-311+G** calculations) in solution, 2-hetaryl-4,5,6,7-tetrachloro- and 2-hetaryl-5,6,7-trichloro-1,3-tropolones exist in the NH-tautomeric form with a strong resonance-assisted

Half-sandwich nickel(II) complexes bearing 1,3-di(cycloalkyl)imidazol-2-ylidene ligands

• Johnathon Yau,
• Kaarel E. Hunt,
• Laura McDougall,
• Alan R. Kennedy and
• David J. Nelson

Beilstein J. Org. Chem. 2015, 11, 2171–2178, doi:10.3762/bjoc.11.235

• . The new species were fully characterised using methods including NMR spectroscopy and X-ray crystallography. When tested in model Suzuki–Miyaura cross-coupling reactions, these complexes were found to be active for the cross-coupling of aryl bromides and aryl chlorides. Keywords: catalysis; cross

• , elemental analysis and X-ray crystallography (Figure 1). Selected crystallographic data can be found in Table 1, and some key bond lengths in Table 2. X-ray quality crystals were obtained by slow diffusion of pentane into a DCM solution of each complex. The 1H NMR spectra show the expected features; a sharp

Investigation of the role of stereoelectronic effects in the conformation of piperidones by NMR spectroscopy and X-ray diffraction

• Cesar Garcias-Morales,
• David Ortegón-Reyna and
• Armando Ariza-Castolo

Beilstein J. Org. Chem. 2015, 11, 1973–1984, doi:10.3762/bjoc.11.213

• -97 [69] and refined by the full-matrix least-squares method on F2 with SHELXL-97. Note that in this report we use our crystallography results of compounds 1, 3, 5, 6, and 7. Details of the calculations and computational methods The computational chemistry calculations were performed using the

[2.2]Paracyclophane derivatives containing tetrathiafulvalene moieties

• Laura G. Sarbu,
• Lucian G. Bahrin,
• Peter G. Jones,
• Lucian M. Birsa and
• Henning Hopf

Beilstein J. Org. Chem. 2015, 11, 1917–1921, doi:10.3762/bjoc.11.207

• aliphatic hydrogen atoms from the dialkylamino groups, and the 13C NMR spectra show the signals at ca. 196 ppm attributable to the thiocarbonyl group. Finally, the structure of 2-([2.2]paracyclophan-4-yl)-2-oxoethyl-N,N-dimethyldithiocarbamate (4a) was unambiguously confirmed by X-ray crystallography

• this reaction. The formation of 1,3-dithiol-2-thione 6 is supported by the NMR and mass spectrometry data. Moreover, the structure of 1,3-dithiol-2-thione 6 was confirmed by X-ray crystallography (Figure 2). The asymmetric unit contains two molecules, which differ in the orientation of the 1,3-dithiol

Synthesis and structures of ruthenium–NHC complexes and their catalysis in hydrogen transfer reaction

• Chao Chen,
• Chunxin Lu,
• Qing Zheng,
• Shengliang Ni,
• Min Zhang and
• Wanzhi Chen

Beilstein J. Org. Chem. 2015, 11, 1786–1795, doi:10.3762/bjoc.11.194

• acetonitrile protons appear at 2.35 and 2.08 ppm as two singlets. The 13C NMR spectrum of 3 exhibits a resonance peak at 190 ppm, which is ascribed to the carbenic carbon atom. Complex 3 has been further identified by X-ray crystallography and the cationic structure of molecular 3 is depicted in Figure 3. The

• using nickel–NHC as the carbene source. Their structures have been definitely determined by X-ray crystallography. The catalytic behavior of di-, tetra- and tri-acetonitrile-coordinated ruthenium complexes in transfer hydrogenation reactions was studied. These ruthenium complexes were found to be highly

Deproto-metallation of N-arylated pyrroles and indoles using a mixed lithium–zinc base and regioselectivity-computed CH acidity relationship

• Mohamed Yacine Ameur Messaoud,
• Ghenia Bentabed-Ababsa,
• Madani Hedidi,
• Aïcha Derdour,
• Floris Chevallier,
• Yury S. Halauko,
• Oleg A. Ivashkevich,
• Vadim E. Matulis,
• Laurent Picot,
• Valérie Thiéry,
• Thierry Roisnel,
• Vincent Dorcet and
• Florence Mongin

Beilstein J. Org. Chem. 2015, 11, 1475–1485, doi:10.3762/bjoc.11.160

• spectrometer at 300 and 75 MHz, respectively. 1H chemical shifts (δ) are given in ppm relative to the solvent residual peak, 13C chemical shifts are relative to the central peak of the solvent signal [55]. Mass spectra measurements were performed using a HP 6890 instrument. Crystallography. The single crystals