Synthesis of 2H-furo[2,3-c]pyrazole ring systems through silver(I) ion-mediated ring-closure reaction

• Vaida Milišiūnaitė,
• Rūta Paulavičiūtė,
• Eglė Arbačiauskienė,
• Vytas Martynaitis,
• Wolfgang Holzer and
• Algirdas Šačkus

Beilstein J. Org. Chem. 2019, 15, 679–684, doi:10.3762/bjoc.15.62

• ]pyrazoles was explored (Scheme 2). For substrates 3b–j, the reactions were complete after 14 hours at 120 °C, and products 4b–j were generated in fair to excellent yields. The structural assignments of 4a–j were based on multinuclear NMR and IR spectroscopy as well as high-resolution mass spectrometry (HRMS

Coordination-driven self-assembly of discrete Ru₆–Pt₆ prismatic cages

• Aderonke Ajibola Adeyemo and
• Partha Sarathi Mukherjee

Beilstein J. Org. Chem. 2018, 14, 2242–2249, doi:10.3762/bjoc.14.199

• –ruthenium(II) clips (1a(NO3)2 and 1b(NO3)2) and a tritopic platinum(II) metalloligand 2 has been performed in methanol at room temperature. The [3 + 2] hexanuclear cages 3a and 3b were isolated in good yields and characterized by well-known spectroscopic techniques including multinuclear NMR, mass

• was ascertained by multinuclear NMR experiments and ESIMS analyses. An upfield shift was observed in the pyridyl protons of cage 3b as compared to the free triplatinum metalloligand 2 in their 1H NMR spectra while cage 3a exhibited a downfield shift in the pyridyl protons (Figure 1 and Supporting

• cages are confirmed by multinuclear NMR and ESIMS studies. The optimized structures of cages 3a and 3b showed large prismatic cages composed of twelve metal centers comprising six ruthenium(II) and six platinum(II) metal centers thus showcasing how two different metal components can be incorporated to

Silica-supported sulfonic acids as recyclable catalyst for esterification of levulinic acid with stoichiometric amounts of alcohols

• Raimondo Maggi,
• N. Raveendran Shiju,
• Veronica Santacroce,
• Giovanni Maestri,
• Franca Bigi and
• Gadi Rothenberg

Beilstein J. Org. Chem. 2016, 12, 2173–2180, doi:10.3762/bjoc.12.207

• chromatography on silica gel (eluent = hexane/ethyl acetate) and characterised by multinuclear NMR. Anchoring methodologies: a) impregnation; b) covalent binding. Activity of the supported sulfonic acid catalyst within the first six cycles. Reaction conditions: 1 mol % cat., acid:alcohol ratio = 1:1, solvent

Smart molecules for imaging, sensing and health (SMITH)

• Bradley D. Smith

Beilstein J. Org. Chem. 2015, 11, 2540–2548, doi:10.3762/bjoc.11.274

• lithium enolates in a weakly polar solvents using a range of multinuclear NMR methods [2]. The work involved vacuum line preparation of the samples and extensive measurements of NMR parameters. Jackman was a wonderful academic advisor, a passionate scientist who also enjoyed sports and recreation. He was

Synthesis of γ-hydroxypropyl P-chirogenic (±)-phosphorus oxide derivatives by regioselective ring-opening of oxaphospholane 2-oxide precursors

• Iris Binyamin,
• Shoval Meidan-Shani and
• Nissan Ashkenazi

Beilstein J. Org. Chem. 2015, 11, 1332–1339, doi:10.3762/bjoc.11.143

• reagents such as aliphatic (Me, Et), aromatic (Ph), cyclic (cyclopentyl) or allylic derivativess (Table 1). The products were identified by multinuclear NMR and MS (CI) detection. Generally, the reaction was performed in cooled (0 ºC) ether, using 3 equiv of the Grignard reagent, while warming to rt with

Synthesis, characterization and DNA interaction studies of new triptycene derivatives

• Sourav Chakraborty,
• Snehasish Mondal,
• Rina Kumari,
• Sourav Bhowmick,
• Prolay Das and
• Neeladri Das

Beilstein J. Org. Chem. 2014, 10, 1290–1298, doi:10.3762/bjoc.10.130

• . Subsequently, derivatization of ethynyl-substituted triptycenes was studied to yield the respective propiolic acid and ethynylphosphine derivatives. Characterization of the newly functionalized triptycene derivatives and their regioisomers were carried out using FTIR and multinuclear NMR spectroscopy, mass

• multinuclear NMR spectroscopy, mass spectrometry, and elemental analyses techniques. We have also studied the photophysical properties of all triptycene derivatives. Furthermore, we have explored a new face of triptycene-based molecules, viz., interaction of tripodal triptycene-based molecules (with various

• hydrochloric acid and subsequent reaction with sodium azide yielded the triazidotriptycene 3 and 4 in 81% and 76% yield respectively. The newly synthesized triethynyltriptycenes (TETs) and triazidotriptycenes (TATs) were characterized by FTIR, multinuclear NMR (1H and 13C), LRMS, and elemental analyses. In

Structure of 1,5-benzodiazepinones in the solid state and in solution: Effect of the fluorination in the six-membered ring

• Marta Pérez-Torralba,
• Rosa M. Claramunt,
• M. Ángeles García,
• Concepción López,
• M. Carmen Torralba,
• M. Rosario Torres,
• Ibon Alkorta and
• José Elguero

Beilstein J. Org. Chem. 2013, 9, 2156–2167, doi:10.3762/bjoc.9.253

• solid state. Keywords: benzodiazepinones; DFT; GIAO calculations; inversion barriers; multinuclear NMR; tautomerism; X-ray structures; Introduction In our previous paper [1] we already reported the relevance of 1,5-benzodiazepine derivatives in central nervous system pathologies as well as for other

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

• single crystals of the macrocycle 2c have so far been unsuccessful. However, the analysis of multinuclear NMR (1H, 13C and 19F) in concurrence with the ESIMS study is fully consistent with the formation of a [4 + 2] self-assembled octanuclear metallacage. In view toward gaining further insight into the

Synthesis of dye/fluorescent functionalized dendrons based on cyclotriphosphazene

• Aurélien Hameau,
• Sabine Fuchs,
• Régis Laurent,
• Jean-Pierre Majoral and
• Anne-Marie Caminade

Beilstein J. Org. Chem. 2011, 7, 1577–1583, doi:10.3762/bjoc.7.186

• substoichiometric amount of phenol was used, in order to avoid disubstitution with phenols 5 or 2 (the A function). The monosubstituted products 6 and 7 were isolated in moderate yield after work-up (51.7 and 48.3%, respectively) (Scheme 2). Both compounds were characterized by multinuclear NMR, in particular by

• were isolated in good yields after work-up (69.2 and 56.6%), and characterized by mass spectrometry and multinuclear NMR. The 31P NMR spectra generally consisted of multiplets, due to the non-symmetrical nature of these compounds. The aldehyde group is directly usable for grafting, as we have already