Towards allosteric receptors – synthesis of β-cyclodextrin-functionalised 2,2’-bipyridines and their metal complexes

• Christopher Kremer,
• Gregor Schnakenburg and
• Arne Lützen

Beilstein J. Org. Chem. 2014, 10, 814–824, doi:10.3762/bjoc.10.77

• receptors whose recognition behaviour can be largely influenced by those effectors. We are currently evaluating the host–guest chemistry of these compounds and their metal complexes which will be reported in near future. X-ray crystal structure analysis of [(CO)3Re(14)Cl] (colour code: petrol: rhenium, grey

• -induced shifts of the individual signals. X-ray crystal structure analysis of [Cu(H3CCN)2(22)]BF4 and [Zn(22)2](OTf)2 (counterions are omitted, colour code: orange: copper, petrol: zinc, grey: carbon, red: oxygen, blue: nitrogen, white: hydrogen). Aromatic region of the 1H NMR spectra (400.1 MHz, 293 K

Intermediates in monensin biosynthesis: A late step in biosynthesis of the polyether ionophore monensin is crucial for the integrity of cation binding

• Wolfgang Hüttel,
• Jonathan B. Spencer and
• Peter F. Leadlay

Beilstein J. Org. Chem. 2014, 10, 361–368, doi:10.3762/bjoc.10.34

• a decisive effect on the three-dimensional structure of the ionophore-cation complex, as revealed by X-ray crystal structure analysis of both dehydroxymonensin A and demethylmonensin A, each in complex with a sodium ion. Results and Discussion PCR-targetted in-frame deletions using the ReDirect [21

Organobase-catalyzed three-component reactions for the synthesis of 4H-2-aminopyrans, condensed pyrans and polysubstituted benzenes

• Moustafa Sherief Moustafa,
• Saleh Mohammed Al-Mousawi,
• Maghraby Ali Selim,
• Ahmed Mohamed Mosallam and
• Mohamed Hilmy Elnagdi

Beilstein J. Org. Chem. 2014, 10, 141–149, doi:10.3762/bjoc.10.11

• acid derivatives 31a,b, ethyl 4-amino-5H-pyrano[2,3-d]pyrimidine-6-carboxylates 33a,b, 4-amino-6H-pyrrolo[3,4-g]quinazoline-9-carbonitrile 39, and 1,7-diamino-6-(N'-hydroxycarbamimidoyl)-3-oxo-5-phenyl-3H-isoindole-4-carboxylate 40. X-ray crystal structure of 9. X-ray crystal structure of 13a. X-ray

• crystal structure of 18. X-ray crystal structure of 21. X-ray crystal structure of 26. X-ray crystal structure of 27a. X-ray crystal structure of 28b. X-ray crystal structure of 31a. X-ray crystal structure of 31b. X-ray crystal structure of 33a. X-ray crystal structure of 37a. X-ray crystal structure of

• 37b. X-ray crystal structure of 39. Reaction of active methylenenitriles with α,β-unsaturated ketones 1. Synthesis of 2-amino-4-phenyl-3-cyanopyridines 2. Synthesis of polysubstituted benzenes 3. Syntheses of compound 9 and compounds 13a,b. Syntheses of compounds 18 and 21. Syntheses of compound 26

Studies toward bivalent κ opioids derived from salvinorin A: heteromethylation of the furan ring reduces affinity

• Thomas A. Munro,
• Wei Xu,
• Douglas M. Ho,
• Lee-Yuan Liu-Chen and
• Bruce M. Cohen

Beilstein J. Org. Chem. 2013, 9, 2916–2924, doi:10.3762/bjoc.9.328

• Information File 429: Synthetic procedures and 1H and 13C NMR spectra of all new compounds; HMQC and HMBC spectra from Figure 5; supporting Figure S1 and Table S1. Supporting Information File 430: 1H and 13C NMR spectra of all new compounds in jcamp-dx format. Supporting Information File 431: X-ray crystal

• structure of 2. Supporting Information File 432: Structure factors for 2. Acknowledgements Funding for this work was provided by the National Institute of Drug Abuse (P30 DA13429 to LYLC). Cécile Béguin suggested compounds for the negative modulation assay.

Efficient synthesis of dihydropyrimidinones via a three-component Biginelli-type reaction of urea, alkylaldehyde and arylaldehyde

• Haijun Qu,
• Xuejian Li,
• Fan Mo and
• Xufeng Lin

Beilstein J. Org. Chem. 2013, 9, 2846–2851, doi:10.3762/bjoc.9.320

• DHPMs by using a chiral SPINOL-phosphoric acid as the catalyst. Crystallographic Data Single crystal data for compound 4a (CCDC 918944) has been deposited in the Cambridge Crystallographic Data Centre. These data can be obtained free of charge via http://www.ccdc.cam.ac.uk/data_request/cif. X-ray

• crystal structure of 4a. Scope of the enantioselective reaction. Reaction conditions: 5a (10 mol %, 0.02 mmol), 1 (0.2 mmol), 2 (0.2 mmol), 3 (0.3 mmol), MS 4 Å (0.1 g), toluene (1 mL), rt, 2 days. Isolated Yields were given. The ee’s were determined by chiral HPLC. Possible mechanism. Optimization of

Less reactive dipoles of diazodicarbonyl compounds in reaction with cycloaliphatic thioketones – First evidence for the 1,3-oxathiole–thiocarbonyl ylide interconversion

• Valerij A. Nikolaev,
• Alexey V. Ivanov,
• Ludmila L. Rodina and
• Grzegorz Mlostoń

Beilstein J. Org. Chem. 2013, 9, 2751–2761, doi:10.3762/bjoc.9.309

• precipitate was separated by filtration and washed with dichloromethane (2 × 1–2 mL). The solvents from the filtrate were evaporated and the reaction products from the residue were isolated by recrystallization or chromatography. X-ray crystal-structure determination of 3a. All measurements were performed on

Synthesis of axially chiral gold complexes and their applications in asymmetric catalyses

• Yin-wei Sun,
• Qin Xu and
• Min Shi

Beilstein J. Org. Chem. 2013, 9, 2224–2232, doi:10.3762/bjoc.9.261

• was identified as 1:2 on the basis of 1H NMR spectroscopic data. After recrystallization from the mixed solvent of DCM and pentane, the single crystals of diastereomers (S)-15a and (S)-15b were obtained and their structures were confirmed by the X-ray crystal structure diffraction (Figure 2 and Figure

• purification with silica gel column chromatography. The structure of (S)-18 was confirmed by the X-ray crystal structure diffraction (Figure 4). The distance from the Au atom to the center of the aromatic ring (C11, C12 and C17–C20) in one naphthyl moiety was 3.3 Å. The compound (S)-19 and NiCl2(dppe) (10 mol

• (S)-diphenyl(2'-phenyl-1,1'-binaphthyl-2-yl)phosphine (21) in 81% yield. The corresponding gold complex (S)-22 was obtained in 91% yield upon treating (S)-21 with the same method as the gold complex (S)-18. The structure of (S)-22 was confirmed by X-ray crystal structure diffraction (Figure 5). The

Synthesis of the reported structure of piperazirum using a nitro-Mannich reaction as the key stereochemical determining step

• James C. Anderson,
• Andreas S. Kalogirou,
• Michael J. Porter and
• Graham J. Tizzard

Beilstein J. Org. Chem. 2013, 9, 1737–1744, doi:10.3762/bjoc.9.200

• (m, 4H), 1.72–1.79 (m, 1H), 1.94–1.99 (m, 2H), 3.50 (dd, J = 6.2, 4.3, 1H, C-6H), 3.79 (m, 1H, C-5H), 4.01 (dd, J = 8.3, 5.3, 1H, C-3H); 13C NMR (150 MHz, D2O) δ 18.8, 20.6, 21.3, 22.0, 22.5, 24.2, 24.7, 25.7, 27.4, 36.3, 38.8, 53.9, 54.9, 56.3, 169.9 (C=O). X-ray crystal structure of 2·HCl

Isolation and X-ray characterization of palladium–N complexes in the guanylation of aromatic amines. Mechanistic implications

• Abdessamad Grirrane,
• Hermenegildo Garcia and
• Eleuterio Álvarez

Beilstein J. Org. Chem. 2013, 9, 1455–1462, doi:10.3762/bjoc.9.165

• Figure 3 present ORTEP views of complexes 4a–c as well as selected views along some crystallographic axes (see Tables S1–S3 and also Figures S7, S11 and S15 in Supporting Information File 1, and for full details of the crystallographic data see Supporting Information File 2). Besides X-ray crystal

• structure analysis, palladium complexes 4a–c were also characterized by NMR spectroscopy, ESIMS and combustion analysis (see experimental section in Supporting Information File 1). 1H, 13C and 19F NMR spectroscopy of 4a–c in CD2Cl2 solution provides evidence showing that under the reaction conditions the

Catalytic asymmetric tandem Friedel–Crafts alkylation/Michael addition reaction for the synthesis of highly functionalized chromans

• Jiahuan Peng and
• Da-Ming Du

Beilstein J. Org. Chem. 2013, 9, 1210–1216, doi:10.3762/bjoc.9.137

• was stirred for another 24 h at room temperature. The solvent was removed under vacuum. Purification by column chromatography afforded the desired products 3. Diphenylamine-linked bis(oxazoline). X-ray crystal structure of the major diastereomer of 3g (one symmetric molecule and two solvent molecules

Carbolithiation of N-alkenyl ureas and N-alkenyl carbamates

• Julien Lefranc,
• Alberto Minassi and
• Jonathan Clayden

Beilstein J. Org. Chem. 2013, 9, 628–632, doi:10.3762/bjoc.9.70

• imines 7 and 8 with di-tert-butyl dicarbonate or with (−)-menthylchloroformate (Scheme 4). The N-alkenylcarbamates 10 and 11 were formed exclusively as their E isomers, and the X-ray crystal structure of E-10 is shown in Figure 2. Vinyl carbamate 9 was treated with primary, secondary or tertiary

• × CHar), 114.4 (2 × CHar), 64.3 (CH-N), 55.3 (O-CH3), 41.0 (N-CH3), 32.6 (CH-CH3), 32.1 (CH2-CH), 30.7 (N-CH3), 29.2 (CH2-CH2-CH3), 23.1 (CH2-CH3), 17.1 (CH3-CH), 14.2 (CH3-CH2); HRMS–ES (m/z): [M + H]+ calcd for C23H33N2O2, 369.2537; found, 369.2536. X-ray crystal structure of urea 6c. X-ray crystal

• structure of carbamate E-10. Carbolithiation of ureas 1. Diastereospecific carbolithiation of ureas 3. Diastereospecific carbolithiation of ureas 5. Synthesis of N-alkenyl carbamates 9–11. Umpolung carbolithiation of carbamates 9 and 10. Organolithium addition to ureas 1. Organolithium additions to ureas 3

Titanium-mediated reductive cross-coupling reactions of imines with terminal alkynes: An efficient route for the synthesis of stereodefined allylic amines

• Kebin Mao,
• Guoqin Fan,
• Yuanhong Liu,
• Shi Li,
• Xu You and
• Dan Liu

Beilstein J. Org. Chem. 2013, 9, 621–627, doi:10.3762/bjoc.9.69

• -ray crystal structure of compound 5c. X-ray crystal structure of compound 8. Titanium-mediated cross-coupling of imines with terminal alkynes. Synthesis of allylic amine 5a by titanium-mediated coupling reaction of imine 2a with 1-heptyne. The regiochemistry of titanium-mediated cross-coupling of

• intermediates and allylic amines are currently in progress. Acknowledegments We thank the National Natural Science Foundation of China (Grant No. 21072208, 21125210, 20821002), Chinese Academy of Science, and the Major State Basic Research Development Program (Grant No. 2011CB808700) for financial support. X

Synthesis and evaluation of cell-permeable biotinylated PU-H71 derivatives as tumor Hsp90 probes

• Tony Taldone,
• Anna Rodina,
• Erica M. DaGama Gomes,
• Matthew Riolo,
• Hardik J. Patel,
• Raul Alonso-Sabadell,
• Danuta Zatorska,
• Maulik R. Patel,
• Sarah Kishinevsky and
• Gabriela Chiosis

Beilstein J. Org. Chem. 2013, 9, 544–556, doi:10.3762/bjoc.9.60

• permeability (Figure 2) and was therefore of limited use and served as a further impetus for the synthesis of the novel probes described here. A critical factor in the design of biotinylated purine-scaffold Hsp90 probes is the site of attachment of biotin. From previous work including X-ray crystal structure

Asymmetric Diels–Alder reaction with >C=P– functionality of the 2-phosphaindolizine-η¹-P-aluminium(O-menthoxy) dichloride complex: experimental and theoretical results

• Rajendra K. Jangid,
• Nidhi Sogani,
• Neelima Gupta,
• Raj K. Bansal,
• Moritz von Hopffgarten and
• Gernot Frenking

Beilstein J. Org. Chem. 2013, 9, 392–400, doi:10.3762/bjoc.9.40

• formation of the cationic species 13 (Scheme 4). Furthermore, it has been established by X-ray crystal structure studies that Cr(CO)5 is coordinated to the phosphorus atom only, and no chelate complex involving the σ2,λ3-P atom and carbonyl oxygen atom is formed [27]. As reported recently, the DFT

One-pot tandem cyclization of enantiopure asymmetric cis-2,5-disubstituted pyrrolidines: Facile access to chiral 10-heteroazatriquinanes

• Ping-An Wang,
• Sheng-Yong Zhang and
• Henri B. Kagan

Beilstein J. Org. Chem. 2013, 9, 265–269, doi:10.3762/bjoc.9.32

• -heteroazatriquinanes are currently being investigated in our laboratory. The structures of azatriquinanes and azatriquinacene. The synthesis of 4 (previous work). X-ray crystal structure of compound 5a. X-ray crystal structure of compound 7b. The structural comparison of chiral ammonium salts such as 7 with the chiral

A new synthetic protocol for coumarin amino acid

• Xinyi Xu,
• Xiaosong Hu and
• Jiangyun Wang

Beilstein J. Org. Chem. 2013, 9, 254–259, doi:10.3762/bjoc.9.30

• ]. Nevertheless, crystallization of the TAG38 mutant thioredoxin is under way to obtain the X-ray crystal structure of it, which will give direct proof of the exclusive incorporation of the L-enantiomer of 1a. 6-Halogenated derivatives were also synthesized with this new protocol; these derivatives should have

Development of peptidomimetic ligands of Pro-Leu-Gly-NH₂ as allosteric modulators of the dopamine D₂ receptor

• Swapna Bhagwanth,
• Ram K. Mishra and
• Rodney L. Johnson

Beilstein J. Org. Chem. 2013, 9, 204–214, doi:10.3762/bjoc.9.24

• ] and computational studies [16] indicated that PLG, although a flexible molecule, assumes turn conformations. The X-ray crystal structure of PLG showed that it existed in a type II β-turn [17]. We began our PLG peptidomimetic development studies by trying to understand what is the bioactive

Organocatalytic cascade aza-Michael/hemiacetal reaction between disubstituted hydrazines and α,β-unsaturated aldehydes: Highly diastereo- and enantioselective synthesis of pyrazolidine derivatives

• Zhi-Cong Geng,
• Jian Chen,
• Ning Li,
• Xiao-Fei Huang,
• Yong Zhang,
• Ya-Wen Zhang and
• Xing-Wang Wang

Beilstein J. Org. Chem. 2012, 8, 1710–1720, doi:10.3762/bjoc.8.195

• . X-ray crystal structure of racemic 4a (25% thermal ellipsoids). X-ray crystal structure of racemic 4n (25% thermal ellipsoids). The X-ray crystal structure of chiral compound 4s (40% thermal ellipsoids). Secondary amine catalyzed cascade aza-Michael/hemiacetal reaction. Substrate scope for the

Regioselective synthesis of 7,8-dihydroimidazo[5,1-c][1,2,4]triazine-3,6(2H,4H)-dione derivatives: A new drug-like heterocyclic scaffold

• Nikolay T. Tzvetkov,
• Harald Euler and
• Christa E. Müller

Beilstein J. Org. Chem. 2012, 8, 1584–1593, doi:10.3762/bjoc.8.181

• % obtained by the literature procedure [14]. Compounds 7–11 were isolated after chromatographic purification in good to excellent yields and analyzed by NMR spectroscopy (1H and 13C) and LC/ESI-MS. In addition, we obtained an X-ray crystal structure of 11 [18], which confirmed the alkylation at the N3

The crystal structure of the Dess–Martin periodinane

• Albert Schröckeneder,
• Desiree Stichnoth,
• Peter Mayer and
• Dirk Trauner

Beilstein J. Org. Chem. 2012, 8, 1523–1527, doi:10.3762/bjoc.8.172

• the first X-ray crystal structure of DMP (1). This could serve as a basis for computational investigations concerning the mechanism of the Dess–Martin oxidation. Results and Discussion The difficulty in obtaining suitable single crystals for X-ray diffraction analysis of DMP (1) may lie in the high

Synthesis of a novel chemotype via sequential metal-catalyzed cycloisomerizations

• Bo Leng,
• Stephanie Chichetti,
• Shun Su,
• Aaron B. Beeler and
• John A. Porco Jr.

Beilstein J. Org. Chem. 2012, 8, 1338–1343, doi:10.3762/bjoc.8.153

• , 52.7, 30.5, 26.4, 12.2; IR (thin film) νmax: 2953, 2926, 2870, 1761, 1741, 1679, 1639, 1493, 1435, 1341, 1253, 1194, 1144, 1073, 1018, 912, 774, 749 cm−1; HRMS–ESI+ (m/z): [M + Na]+ calcd for C19H20O6, 367.1158; found, 367.1189. Reaction screen with diynyl benzaldehyde 3. X-ray crystal structure of

The preferred conformation of erythro- and threo-1,2-difluorocyclododecanes

• Yi Wang,
• Peer Kirsch,
• Tomas Lebl,
• Alexandra M. Z. Slawin and
• David O'Hagan

Beilstein J. Org. Chem. 2012, 8, 1271–1278, doi:10.3762/bjoc.8.143

• -difluorocyclododecanes (5a and 5b). X-ray crystal structure of threo-1,2-difluorocyclododecane (5b) showing corner angles and representative transannular contact distances. Variable-temperature 19F{1H} NMR of erythro- (5a) and threo-1,2-difluorocyclododecane (5b). Calculated relative energies of the conformations of the

Chiral multifunctional thiourea-phosphine catalyzed asymmetric [3 + 2] annulation of Morita–Baylis–Hillman carbonates with maleimides

• Hong-Ping Deng,
• De Wang,
• Yin Wei and
• Min Shi

Beilstein J. Org. Chem. 2012, 8, 1098–1104, doi:10.3762/bjoc.8.121

• ee values under the standard conditions (Table 2, entries 16–18). The absolute configuration of the major product 3r was determined as (1S,2R,3S) by X-ray crystal structure. Its ORTEP plot is shown in Figure 1 and the corresponding CIF data are presented in the Supporting Information File 2 [58]. As

Expanding the chemical diversity of spirooxindoles via alkylative pyridine dearomatization

• Chunhui Dai,
• Bo Liang and
• Corey R. J. Stephenson

Beilstein J. Org. Chem. 2012, 8, 986–993, doi:10.3762/bjoc.8.111

• conditions are very mild and tolerant of functional groups, providing moderate to high yields. The application and versatility of these spirooxindole derivatives to quickly access complex molecules is further demonstrated in good yielding D–A reactions. X-ray crystal structure of compound 6b. X-ray crystal

• structure of compound 3d. X-ray crystal structure of compound 8a. Unexpected alkylative pyridine dearomatization during our previous work on the synthesis of spirooxindole pyranochromenediones. Application of spiro [1,3]oxazino compound 3a in D–A reactions. Reaction of isatins 4 and 1,3-dicarbonyl compounds

On the bromination of the dihydroazulene/vinylheptafulvene photo-/thermoswitch

• Virginia Mazzanti,
• Martina Cacciarini,
• Søren L. Broman,
• Christian R. Parker,
• Magnus Schau-Magnussen,
• Andrew D. Bond and
• Mogens B. Nielsen

Beilstein J. Org. Chem. 2012, 8, 958–966, doi:10.3762/bjoc.8.108

• , the dibromide 3 as well as the known tetrabromide 18 [5] slowly turned into a mixture of azulenes, which we isolated and identified as 19–22 shown in Scheme 8. While, 19 (X-ray crystal structure is given in [6]), 20 [5], and 21 [5][14][15] are already known, the dibromoazulene 22 is new. UV–vis

• optical and redox properties [13]. The two bromo positions of 14 showed very different reactivity. Thus, subjecting 14 to a Sonogashira coupling with triisopropylsilylacetylene by using the Pd(PPh3)2Cl2/CuI catalyst system only gave the monocoupled product 15 (Scheme 7), confirmed by X-ray crystal

• structure analysis (Figure 3d). Moreover, a Suzuki cross-coupling reaction with boronic acid 16 gave the product 17, albeit in rather low yield (Scheme 7). The substitution was confirmed by NOESY 1D experiments (see Supporting Information File 1). Finally, we observed that upon storage at room temperature