Studies on the interaction of isocyanides with imines: reaction scope and mechanistic variations

• Ouldouz Ghashghaei,
• Consiglia Annamaria Manna,
• Esther Vicente-García,
• Marc Revés and
• Rodolfo Lavilla

Beilstein J. Org. Chem. 2014, 10, 12–17, doi:10.3762/bjoc.10.3

• monocrystal of the bis(imino)azetidine 3a was subjected to X-ray diffraction analysis and the solid state structure is depicted in Figure 1 [11]. This result confirms the structural features associated to this scaffold, and also raises some questions on the origin of the stereochemistry associated to the C=N

• that can account for the production of this rich structural outcome has been proposed. X-ray diffraction analysis of azetidine 3a. Azetidine formation from the interaction of imines with isocyanides. Reaction conditions. Stepwise mechanism for the formation of azetidine 3a. Manifold reaction mechanism

Synthetic scope and DFT analysis of the chiral binap–gold(I) complex-catalyzed 1,3-dipolar cycloaddition of azlactones with alkenes

• María Martín-Rodríguez,
• Luis M. Castelló,
• Carmen Nájera,
• José M. Sansano,
• Olatz Larrañaga,
• Abel de Cózar and
• Fernando P. Cossío

Beilstein J. Org. Chem. 2013, 9, 2422–2433, doi:10.3762/bjoc.9.280

• as base and toluene as solvent at 120 °C. Polycyclic compound 15 was finally obtained in 50% yield as single diastereoisomer (Scheme 8). Despite being a solid product it was not possible to perform an X-ray diffraction analysis. Positive (CH derived from NPM with the CH derived from NMM) nOe

Sequential Diels–Alder/[3,3]-sigmatropic rearrangement reactions of β-nitrostyrene with 3-methyl-1,3-pentadiene

• Peter A. Wade,
• Alma Pipic,
• Matthias Zeller and
• Panagiota Tsetsakos

Beilstein J. Org. Chem. 2013, 9, 2137–2146, doi:10.3762/bjoc.9.251

• combined chromatographic and recrystallization methods. The structure of nitro compound 12a,b is based on spectral data. However, isomer identification required single-crystal X-ray diffraction analysis, performed on the enriched sample (12a,b 91.4:8.6 ratio, respectively). The ternary adduct 12a,b is a

Anionic cascade reactions. One-pot assembly of (Z)-chloro-exo-methylenetetrahydrofurans from β-hydroxyketones

• István E. Markó and
• Florian T. Schevenels

Beilstein J. Org. Chem. 2013, 9, 1319–1325, doi:10.3762/bjoc.9.148

• -derivative 36 were obtained as a 1:5 mixture of diastereoisomers that could be separated (Scheme 6). Their structure was unambiguously established by single-crystal X-ray diffraction analysis, as shown in Figure 1. Increasing the steric hindrance at the tertiary alcohol site resulted in the exclusive

• unambiguously established as the spirocyclic dimer 41 by single-crystal X-ray diffraction analysis. It is noteworthy that a single diastereoisomer was generated in this transformation. The formation of these unique compounds can be rationalized as depicted in Scheme 8. Under acidic conditions, the (Z)-chloro

• established by single-crystal X-ray diffraction analysis (Figure 2). Once again, increasing the steric effect around the tertiary alcohol function of the (Z)-chloro-exo-methylenetetrahydrofurans has a profound influence on the fate of the condensation reaction. A plausible mechanistic rationale is provided in

Use of 3-[¹⁸F]fluoropropanesulfonyl chloride as a prosthetic agent for the radiolabelling of amines: Investigation of precursor molecules, labelling conditions and enzymatic stability of the corresponding sulfonamides

• Reik Löser,
• Steffen Fischer,
• Achim Hiller,
• Martin Köckerling,
• Uta Funke,
• Aurélie Maisonial,
• Peter Brust and
• Jörg Steinbach

Beilstein J. Org. Chem. 2013, 9, 1002–1011, doi:10.3762/bjoc.9.115

• product 18. This compound was obtained in the form of crystals suitable for X-ray diffraction analysis. The molecular structure of 18 is shown in Figure 2A, confirming unambiguously its identity as N-(4-nitrophenyl)-3-fluoropropane-1-sulfonamide. Crystal data and structure refinement parameters are

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

• CH2Cl2, suitable for X-ray diffraction analysis. It was found that the ring-closing reaction took place during the heating process following N-methylation to provide the rigid 1-oxo-3-aza-10-azaquinane skeleton 7b as its ammonium salt. Compound 7b contains four stereogenic centers, and their

Inclusion of the insecticide fenitrothion in dimethylated-β-cyclodextrin: unusual guest disorder in the solid state and efficient retardation of the hydrolysis rate of the complexed guest in alkaline solution

• Dyanne L. Cruickshank,
• Natalia M. Rougier,
• Raquel V. Vico,
• Susan A. Bourne,
• Elba I. Buján,
• Mino R. Caira and
• Rita H. de Rossi

Beilstein J. Org. Chem. 2013, 9, 106–117, doi:10.3762/bjoc.9.14

• its volatility (and hence toxicity) by conversion of the liquid pesticide into a solid phase. Experimental The compounds used in this study were purified as indicated before [6]. Crystal preparation and X-ray diffraction analysis Fenitrothion (1, 20 mg, ~0.072 mmol) was added to a saturated aqueous

Asymmetric synthesis of γ-chloro-α,β-diamino- and β,γ-aziridino-α-aminoacylpyrrolidines and -piperidines via stereoselective Mannich-type additions of N-(diphenylmethylene)glycinamides across α-chloro-N-sulfinylimines

• Gert Callebaut,
• Sven Mangelinckx,
• Pieter Van der Veken,
• Karl W. Törnroos,
• Koen Augustyns and
• Norbert De Kimpe

Beilstein J. Org. Chem. 2012, 8, 2124–2131, doi:10.3762/bjoc.8.239

• diastereoselectivity of the Mannich-type addition of glycinamides 4 across chiral α-chloro-N-p-toluenesulfinylaldimines 3 was independent of the base used. The absolute stereochemistry of (SS,2S,3S)-γ-chloro-α,β-diaminocarboxylamides syn-5 was unambiguously determined by means of an X-ray diffraction analysis of

Iridium-catalyzed intramolecular [4 + 2] cycloadditions of alkynyl halides

• Andrew Tigchelaar and
• William Tam

Beilstein J. Org. Chem. 2012, 8, 1765–1770, doi:10.3762/bjoc.8.201

• ] cycloadditions in which the relative stereochemistry was assigned by X-ray diffraction analysis [32] or GOESY NMR [33]. For both alkynyl bromide 1a and alkynyl chloride 1b (Table 3, entries 1 and 2) the reaction went to completion quite quickly; however, a decreased yield was seen in the cycloaddition of 1b

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

Approaches to α-amino acids via rearrangement to electron-deficient nitrogen: Beckmann and Hofmann rearrangements of appropriate carboxyl-protected substrates

• Sosale Chandrasekhar and
• V. Mohana Rao

Beilstein J. Org. Chem. 2012, 8, 1393–1399, doi:10.3762/bjoc.8.161

• . All products were generally purified chromatographically and fully characterized spectroscopically (including HRMS). In addition, two of the final carbamates (10a and 10b) were confirmed by X-ray diffraction analysis (Figure 2 and Table 4) [24]. The carbamates 10 apparently evidenced restricted

Self-assembly of Ru₄ and Ru₈ assemblies by coordination using organometallic Ru(II)₂ precursors: Synthesis, characterization and properties

• Sankarasekaran Shanmugaraju,
• Dipak Samanta and
• Partha Sarathi Mukherjee

Beilstein J. Org. Chem. 2012, 8, 313–322, doi:10.3762/bjoc.8.34

• salts in high yields and were characterized fully by multinuclear (1H, 13C and 19F) NMR, infrared (IR) and electrospray ionization mass spectrometry (ESIMS). In addition, the molecular structure of macrocycle 2a was established unequivocally by single-crystal X-ray diffraction analysis and adopts a

• -crystal X-ray diffraction analysis, which reveals a tetranuclear geometry with the dimensions of 5.53 Å × 12.39 Å. In addition to their synthesis and characterization, the UV–vis absorption and cyclic voltammetry studies are reported. Results and Discussion Synthesis and characterization of the

• molecular structure of the tetranuclear metallamacrocycle [(p-cymene)4Ru4(μ-η4-oxalato)2(L)]4+(O3SCF3−)4 (2a) was unambiguously determined by single-crystal X-ray diffraction analysis. Single crystals of 2a of high enough quality for X-ray diffraction were grown by slow vapor diffusion of diethyl ether into

Continuous preparation of carbon-nanotube-supported platinum catalysts in a flow reactor directly heated by electric current

• Alicja Schlange,
• Antonio Rodolfo dos Santos,
• Ulrich Kunz and
• Thomas Turek

Beilstein J. Org. Chem. 2011, 7, 1412–1420, doi:10.3762/bjoc.7.165

• has much higher dispersion. Powder X-ray diffraction analysis was performed to investigate the crystalline structure of the prepared catalysts and the support material. XRD spectra are given in Figure 5. For pristine carbon nanotubes the diffraction peaks at 30.0° and 50.4° can be attributed to the

Functionalization of anthracene: A selective route to brominated 1,4-anthraquinones

• Kiymet Berkil Akar,
• Osman Cakmak,
• Orhan Büyükgüngör and
• Ertan Sahin

Beilstein J. Org. Chem. 2011, 7, 1036–1045, doi:10.3762/bjoc.7.118

• , however, it was difficult to distinguish the exact stereochemistry of symmetrical compounds 7 and 8 by NMR. Therefore, X-ray diffraction analysis was also carried out for 7. The study confirmed the structure of 7 without any ambiguity (Figure 1). Proton and carbon NMR studies indicated that tetrabromide 8

Photoinduced electron-transfer chemistry of the bielectrophoric N-phthaloyl derivatives of the amino acids tyrosine, histidine and tryptophan

• Axel G. Griesbeck,
• Jörg Neudörfl and
• Alan de Kiff

Beilstein J. Org. Chem. 2011, 7, 518–524, doi:10.3762/bjoc.7.60

• by X-ray diffraction analysis (Figure 2) [11], has also been described in literature as a yellow compound [12][13]. The color is not the consequence of any impurity and did not vanish after several recrystallizations and, more importantly, was also observed for the methyl ester and the

Tandem catalysis of ring-closing metathesis/atom transfer radical reactions with homobimetallic ruthenium–arene complexes

• Yannick Borguet,
• Xavier Sauvage,
• Guillermo Zaragoza,
• Albert Demonceau and
• Lionel Delaude

Beilstein J. Org. Chem. 2010, 6, 1167–1173, doi:10.3762/bjoc.6.133

• NMR tube revealed, however, the formation of a phosphorus-containing precipitate. Suitable crystals for X-ray diffraction analysis were obtained by repeating the RCM experiment on a larger scale in toluene at room temperature. Their structure was solved and assigned to the paramagnetic complex [(p

Anion receptors containing thiazine-1,1-dioxide heterocycles as hydrogen bond donors

• Hong-Bo Wang,
• James A. Wisner and
• Michael C. Jennings

Beilstein J. Org. Chem. 2010, 6, No. 50, doi:10.3762/bjoc.6.50

• installation of this subunit in a potential host. The solid-state structures of both newly synthesized receptors were confirmed by X-ray diffraction analysis of single crystals grown by the slow diffusion of isopropyl ether into concentrated DMSO solutions of each (Figure 3). Unfortunately, attempts to co

Acid catalyzed cyclodimerization of 2,2-bis(trifluoromethyl)-4-alkoxy-oxetanes and -thietanes. Synthesis of 2,2,6,6-tetrakis(trifluoromethyl)-4,8-dialkoxy-1,5-dioxocanes and 3,3,7,7-tetrakis(trifluoromethyl)-9-oxa-2,6-dithia-bicyclo[3.3.1]nonane

• Viacheslav A. Petrov and
• Will Marshall

Beilstein J. Org. Chem. 2010, 6, No. 46, doi:10.3762/bjoc.6.46

• was established by single crystal X-ray diffraction analysis (see Supporting Information File 2). Hydrocarbon oxetanes were reported to react with alcohols under relatively mild conditions [13]. It is interesting, that electron deficient oxetanes 1 also have similar reactivity and rapidly react with

• hexafluoroisopropanol (25 °C, 16 h, NMR) and both 4a and 4b were found to be inert towards BF3·OEt2 (25 °C, 10 h, CH2Cl2, NMR). However, the addition of compounds 4a or 4b to concentrated H2SO4 resulted in an exothermic reaction and formation of a product, which, after single crystal X-ray diffraction analysis, was

Synthesis and binding studies of two new macrocyclic receptors for the stereoselective recognition of dipeptides

• Ana Maria Castilla,
• M. Morgan Conn and
• Pablo Ballester

Beilstein J. Org. Chem. 2010, 6, No. 5, doi:10.3762/bjoc.6.5

• the formation of the peptide bonds of the macrocyclic structures, both receptors have been isolated as single diastereoisomers. The molecular structure of receptor 1 has been confirmed by single-crystal X-ray diffraction analysis. Although molecular modeling suggested that the cyclic receptors can

The enantiospecific synthesis of (+)-monomorine I using a 5-endo- trig cyclisation strategy

• Malcolm B. Berry,
• Donald Craig,
• Philip S. Jones and
• Gareth J. Rowlands

Beilstein J. Org. Chem. 2007, 3, No. 39, doi:10.1186/1860-5397-3-39

• epimeric pairs proved problematic due to difficulties encountered during separation, and the presence of overlapping signals in the 1H NMR spectrum. Finally, a combination of X-ray diffraction analysis and comparison of the 1H NMR showed that the major diastereoisomer in each case was the undesired C-5

Diastereoselective synthesis of some novel benzopyranopyridine derivatives

• Pradeep K. Mohakhud,
• Sujeet M. R. Kumar,
• Vasanth M. R. Kumar,
• Ravi M. R. Kumar,
• Moses D. R. Babu,
• Vyas D. R. K and
• Om D. R. Reddy

Beilstein J. Org. Chem. 2006, 2, No. 25, doi:10.1186/1860-5397-2-25

• determined as S,S by X-ray diffraction analysis (Figure 4) (For details see also: Figure 4 and Supporting Information File 1). Structure elucidation of 5b The mass spectrum of 5b displayed a molecular ion at m/z 245 corresponding to the molecular formula C14H15NO3. Interestingly the molecular ion is 18 amu