A trustworthy mechanochemical route to isocyanides

• Francesco Basoccu,
• Federico Cuccu,
• Federico Casti,
• Rita Mocci,
• Claudia Fattuoni and
• Andrea Porcheddu

Beilstein J. Org. Chem. 2022, 18, 732–737, doi:10.3762/bjoc.18.73

• were obtained when a stoichiometric ratio between the anhydride and the reference compound, N-benzylformamide (1f), was milled with 2 equivalents of triethylamine or N-methylimidazole as bases. Despite slightly performing as a method, the reaction mixture was “too liquid” for running a mechanochemical

• , pyridine handling is associated with many risks, mainly concerning human health [36]. Consequently, our idea was to substitute pyridine with N-methylimidazole because their basicity and physical state are analogous. When the reactions between the formamide and different equivalents (from 1 to 6) of N

• -methylimidazole were carried out, the outcomes were not as good as those already documented with pyridine in the literature. Possible explanations for this phenomenon are either a different electronic distribution between the two heterocycles or the absence of intermolecular interactions caused by the solvent

Photocontrolled DNA minor groove interactions of imidazole/pyrrole polyamides

• Sabrina Müller,
• Jannik Paulus,
• Jochen Mattay,
• Heiko Ihmels,
• Veronica I. Dodero and
• Norbert Sewald

Beilstein J. Org. Chem. 2020, 16, 60–70, doi:10.3762/bjoc.16.8

• promising strategy to obtain photoswitchable Im/Py hairpin polyamides capable of interacting with the dsDNA minor groove only in the Z-configuration. Keywords: azobenzene; DNA minor groove; N-methylimidazole; N-methylpyrrole; photoswitches; polyamide; Introduction The development of small chemical agents

• binders have been developed for all possible base pairings (AT, TA, GC, CG; 'pairing rules'). A GC pair is specifically being addressed in the minor groove by N-methylimidazole/N-methylpyrrole (Im/Py), while AT associates with the pair N-methylpyrrole/N-methylhydroxypyrrole (Py/Hp). The same applies to CG

• required because this allowed for an alignment between hydrogen-bonding groups in long polyamides and in the minor groove of DNA [41]. The Fmoc-protected heterocyclic amino acids 2 were obtained from N-methylpyrrole and N-methylimidazole, respectively (Scheme 2A). The N-terminal N-methylpyrrole and N

Syntheses and chemical properties of β-nicotinamide riboside and its analogues and derivatives

• Mikhail V. Makarov and
• Marie E. Migaud

Beilstein J. Org. Chem. 2019, 15, 401–430, doi:10.3762/bjoc.15.36

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

• -trifluoromethyloxadiazole substituent was not a viable substrate (Table 1, entry 10). Because of a similar result obtained with the N-methylimidazole substituted compound 7k, the difference between 7i and 7j could be explained by the imidazole-like structure of the 5-trifluoromethyloxadiazole moiety. The reduced inductive

Direct catalytic arylation of heteroarenes with meso-bromophenyl-substituted porphyrins

• Alexei N. Kiselev,
• Olga K. Grigorova,
• Alexei D. Averin,
• Sergei A. Syrbu,
• Oskar I. Koifman and
• Irina P. Beletskaya

Beilstein J. Org. Chem. 2017, 13, 1524–1532, doi:10.3762/bjoc.13.152

• , benzothiazole and N-methylimidazole was studied in the presence of three alternative catalytic systems: Pd(dba)2/DavePhos/Cs2CO3, Pd(PPh3)4/PivOH/K2CO3 and Pd(OAc)2/Cu(OAc)2/PPh3/K2CO3. The first catalytic system was found to be successful in the reaction with benzoxazole, the second one was less efficient for

Synthesis of oligonucleotides on a soluble support

• Harri Lönnberg

Beilstein J. Org. Chem. 2017, 13, 1368–1387, doi:10.3762/bjoc.13.134

• pyridine and 2,6-lutidine using 1-(mesitylene-2-sulfonyl)-3-nitro-1,2,4-triazole (MSNT; 6 equiv) as an activator and N-methylimidazole (NMI; 10 equiv) as a nucleophilic catalyst. Each coupling was followed by precipitation/recrystallization from EtOH, capping with Ac2O in pyridine and precipitation from

Copper-catalyzed asymmetric conjugate addition of organometallic reagents to extended Michael acceptors

• Thibault E. Schmid,
• Sammy Drissi-Amraoui,
• Christophe Crévisy,
• Olivier Baslé and
• Marc Mauduit

Beilstein J. Org. Chem. 2015, 11, 2418–2434, doi:10.3762/bjoc.11.263

• the 1,4-adduct 47, and the ethyl moiety was inserted with 74% enantiomeric excess in 78% yield (Scheme 13). Very recently, a new study dealing with the reactivity of unsaturated acyl-N-methylimidazole substrates in copper-catalyzed ACA was released by Mauduit, Campagne and co-workers [33

• ,δ-unsaturated acyl-N-methylimidazole. 1,4-Selectivity in conjugate addition on extended systems with the concomitant use of a chelating chiral hydroxyalkyl NHC and of a Grignard reagent. Cu-NHC catalyzed 1,4-ACA as the key step in the total synthesis of ent-riccardiphenol B. Cu-NHC-catalyzed 1,4

Synthesis of dinucleoside acylphosphonites by phosphonodiamidite chemistry and investigation of phosphorus epimerization

• William H. Hersh

Beilstein J. Org. Chem. 2015, 11, 184–191, doi:10.3762/bjoc.11.19

• triflate as the activator to give the monoamidites 3′-O-(P(N(iPr)2)C(O)R)-5′-O-DMTr-thymidine, and further coupling with 3′-O-(tert-butyldimethylsilyl)thymidine was carried out with activation by pyridinium trifluoroacetate/N-methylimidazole. The new dinucleoside acylphosphonites could be further oxidized

• both 10 and 11 in the 1H and 13C NMR spectra. Since this was not relevant to phosphorus epimerization, it was not further investigated. Dinucleoside coupling was carried out using the 2:1 pyridinium trifluoroacetate/N-methylimidazole (PTFA/NMI) activator developed at Isis to combine phosphonamidites 10

Gold(I)-catalysed synthesis of a furan analogue of thiamine pyrophosphate

• Amjid Iqbal,
• El-Habib Sahraoui and
• Finian J. Leeper

Beilstein J. Org. Chem. 2014, 10, 2580–2585, doi:10.3762/bjoc.10.270

• . Dehydrative cyclization catalysed by gold(I) and its presumed mechanism [31]. Synthesis of furan 12. Reagents and conditions: (i) TBDMS-Cl, N-methylimidazole. (ii) n-BuLi, −78 °C, then 9 and to rt, 55% (iii) TBAF, THF, 79%. (iv) AuCl, THF, 85%. Synthesis of the furan analogue 17 of ThDP. Reagents and

Hybrid super electron donors – preparation and reactivity

• Jean Garnier,
• Douglas W. Thomson,
• Shengze Zhou,
• Phillip I. Jolly,
• Leonard E. A. Berlouis and
• John A. Murphy

Beilstein J. Org. Chem. 2012, 8, 994–1002, doi:10.3762/bjoc.8.112

• bromide (16) [34] with N-methylimidazole (17) afforded disalt 19. Deprotonation with NaH (15 equiv) in DMF then afforded the electron donor 11 in situ; this was reacted with iodine to afford the oxidised diiodide salt, and this was subjected to anion exchange to afford the bis(hexafluorophosphate) salt 21

Synthesis of fluorinated maltose derivatives for monitoring protein interaction by ¹⁹F NMR

• Michaela Braitsch,
• Hanspeter Kählig,
• Georg Kontaxis,
• Michael Fischer,
• Toshinari Kawada,
• Robert Konrat and
• Walther Schmid

Beilstein J. Org. Chem. 2012, 8, 448–455, doi:10.3762/bjoc.8.51

• glacial acetic acid (Scheme 1) [25]. Treatment of bromide 3 with Zn and N-methylimidazole [26] afforded the protected maltal derivative 4, which was transformed to the target compounds by utilizing Selectfluor® as a fluorinating agent [23][27][28] in a nitromethane solution. The mixture of anomeric 2

• relaxation filter. Syntheses of maltose derivatives; reagents and conditions: (a) Ac2O, Pyr, 97%; (b) HBr, AcOH, 99%; (c) Zn, N-methylimidazole, ethyl acetate, 74%; (d) Selectfluor®, CH3NO2, 40%; (e) NaOMe, MeOH, 99%; (f) NH2NH2·HOAc, DMF, 94%; (g) DAST, CH2Cl2, 89%; (h) NaOMe, MeOH, 99%; (i) α,α

CuCl-catalyzed aerobic oxidation of 2,3-allenols to 1,2-allenic ketones with 1:1 combination of phenanthroline and bipyridine as ligands

• Shuxu Gao,
• Yu Liu and
• Shengming Ma

Beilstein J. Org. Chem. 2011, 7, 396–403, doi:10.3762/bjoc.7.51

• , entries 7–12). This may be explained by considering that the coordination of 2,2'-bipyridine is important for the formation of the catalytically active species and may be easily replaced with that of the alcohol. We also tried N-methylimidazole (NMI), which was used in oxidation of primary aliphatic

Michael-type addition of azoles of broad-scale acidity to methyl acrylate

• Sławomir Boncel,
• Kinga Saletra,
• Barbara Hefczyc and
• Krzysztof Z. Walczak

Beilstein J. Org. Chem. 2011, 7, 173–178, doi:10.3762/bjoc.7.24

• reports on the synthesis of Michael-type adducts of azoles by the use of microwave irradiation [7][24]. The optimisation of aza-Michael reactions with N-methylimidazole as the base catalyst was published in 2007 by Liu et al [25]. However, when this catalyst was used with azoles of narrower-scale acidity

A practical synthesis of the ¹³C/¹⁵N- labelled tripeptide N-formyl- Met-Leu-Phe, useful as a reference in solid- state NMR spectroscopy

• Sven T. Breitung,
• Jakob J. Lopez,
• Gerd Dürner,
• Clemens Glaubitz,
• Michael W. Göbel and
• Marcel Suhartono

Beilstein J. Org. Chem. 2008, 4, No. 35, doi:10.3762/bjoc.4.35

• h; 3. piperidine, 30 min. d) HCOOEt, over night. e) TFA, EDT, H2O, TIS (94 : 2.5 : 2.5 : 1), 4.5 h. All reactions were carried out at room temperature. Abbreviations: MSNT = 1-(mesitylene-2-sulphonyl)-3-nitro-1,2,4-triazole, MeIm = N-methylimidazole, DIC = diisopropylcarbodiimide, HOBt = 1