An overview on recent advances in the synthesis of sulfonated organic materials, sulfonated silica materials, and sulfonated carbon materials and their catalytic applications in chemical processes

• Hashem Sharghi,
• Pezhman Shiri and
• Mahdi Aberi

Beilstein J. Org. Chem. 2018, 14, 2745–2770, doi:10.3762/bjoc.14.253

• explored for tetrasubstituted imidazole synthesis from primary amines, aromatic aldehydes, ammonium acetate, and phenylglyoxal. The TFE-modified SMSM had better behavior than others. To highlight the catalytic activity of the RFOH/SBA-15-Pr-SO3H, the reaction was also carried out with non-RFOH

• –270 °C for 20 h, (e) after filtration, washing, and drying, MWCNTs-SO3H composite 97 was achieved (Scheme 17). N-Substituted pyrroles 99 were obtained in good to excellent yields (40–92%) via a simple and green reaction between 2,5-dimethoxytetrahydrofuran (98) and primary amines 15 in water media at

Synthesis and biological evaluation of 1,2-disubstituted 4-quinolone analogues of Pseudonocardia sp. natural products

• Stephen M. Geddis,
• Teodora Coroama,
• Suzanne Forrest,
• James T. Hodgkinson,
• Martin Welch and
• David R. Spring

Beilstein J. Org. Chem. 2018, 14, 2680–2688, doi:10.3762/bjoc.14.245

• primary amines 12, which following metal-catalysed cyclisation would give 1,2-disubstituted quinolones 14. Upon the successful synthesis of analogues of the form 14, biological evaluation of these and the natural products 1, 4 and 5–7 (synthesised during our previous study [11]) would then be possible. In

• resulted for 11b, which was attributed to difficulties in obtaining its precursor 10b with high purity which stemmed from its volatility. These ynones were then subjected to a conjugate addition with an assortment of primary amines 12a–f (Scheme 3). The reactions proceeded with excellent yield in all cases

• of primary amines 12a–f with ynones 11a and 11b. aFollowing concentration in vacuo, further purification using silica gel flash chromatography was required. Cyclisation of precursors 13 to natural product analogues 14 using palladium- or copper-catalysed conditions. Yields quoted are isolated. a13ab

The mechanochemical synthesis of quinazolin-4(3H)-ones by controlling the reactivity of IBX

• Md Toufique Alam,
• Saikat Maiti and
• Prasenjit Mal

Beilstein J. Org. Chem. 2018, 14, 2396–2403, doi:10.3762/bjoc.14.216

• may take place between hypervalent iodine reagents and electron-rich amines. For this reason, synthetic methods based on hypervalent iodine reagents and primary amines under solvent-free conditions or constrained media are limited [8]. Recently, we have described a method for the successful reaction

• of primary amines and hypervalent iodine(III) reagents by controlling the reactivity using an acid salt, NaHSO4, as additive [9]. Results and Discussion The last few decades have witnessed a significant growth in organic synthesis using hypervalent iodines [10][11][12]. Their easy availability, high

• quinazolin-4(3H)-ones (Figure 1d). In a recent report we have shown a successful dehydrogenative cross-coupling or CDC reaction using a combination of primary amines and phenyleneiodine diacetate (PIDA) under solvent-free ball-milling conditions, i.e., at the highest possible contact of the reactants [9

Investigation of the electrophilic reactivity of the biologically active marine sesquiterpenoid onchidal and model compounds

• Melissa M. Cadelis and
• Brent R. Copp

Beilstein J. Org. Chem. 2018, 14, 2229–2235, doi:10.3762/bjoc.14.197

• binneyi) also exhibit biological properties including feeding deterrence, antibacterial and anticholinesterase activities. Chemical reactivity studies using polygodial (1), scalaradial (2) and caulerpenyne (3) have demonstrated evidence of pyrrole formation upon reaction with primary amines, with

Functionalization of graphene: does the organic chemistry matter?

• Artur Kasprzak,
• Agnieszka Zuchowska and
• Magdalena Poplawska

Beilstein J. Org. Chem. 2018, 14, 2018–2026, doi:10.3762/bjoc.14.177

• . Strong nucleophiles (e.g., primary amines or thiols) react with epoxides more rapidly than do weak nucleophiles (e.g., like primary alcohols). This functionalization approach based on the epoxides’ opening enables the introduction of the reactive groups to the surfaces of graphene-family materials. The

An amine protecting group deprotectable under nearly neutral oxidative conditions

• Shahien Shahsavari,
• Chase McNamara,
• Mark Sylvester,
• Emily Bromley,
• Savannah Joslin,
• Bao-Yuan Lu and
• Shiyue Fang

Beilstein J. Org. Chem. 2018, 14, 1750–1757, doi:10.3762/bjoc.14.149

• with 4 and heating excess amine with 4 without any solvent but failed to identify one that could afford useful yields. We also tried to use the optimized conditions for the protection of aliphatic primary amines to protect arylamines, but found that arylamines were not reactive enough for the reaction

Metal-free formal synthesis of phenoxazine

• Gabriella Kervefors,
• Antonia Becker,
• Chandan Dey and
• Berit Olofsson

Beilstein J. Org. Chem. 2018, 14, 1491–1497, doi:10.3762/bjoc.14.126

• [17][19][20]. A Pd-catalyzed double N-arylation using di(2-bromoaryl) ethers and primary amines was recently developed (Scheme 1c) [21]. Furthermore, N-functionalization of the phenoxazine core can be performed under metal-free conditions [22]. Our research group has reported highly efficient O

Synthesis of chiral 3-substituted 3-amino-2-oxindoles through enantioselective catalytic nucleophilic additions to isatin imines

• Hélène Pellissier

Beilstein J. Org. Chem. 2018, 14, 1349–1369, doi:10.3762/bjoc.14.114

• good yields (78–81%) while the presence of a halogen substituent on the oxindole moiety (R2 = 5-F, 5-Cl, 6-Br) resulted in a lowering of both yields (42–68%) and enantioselectivities (15–74% ee). In 2017, Shao et al. investigated the use of simple chiral primary amines to promote the enantioselective

• ligands and organocatalysts. For example, remarkable enantioselectivities of up to 94 to >99% ee have been reported in recent examples of Mannich reactions promoted by organocatalysts, as varied as cinchona-alkaloids, squaramides, phosphoric acids, simple primary amines and L-diphenylprolinol

On the design principles of peptide–drug conjugates for targeted drug delivery to the malignant tumor site

• Eirinaios I. Vrettos,
• Gábor Mező and
• Andreas G. Tzakos

Beilstein J. Org. Chem. 2018, 14, 930–954, doi:10.3762/bjoc.14.80

Phosphodiester models for cleavage of nucleic acids

• Satu Mikkola,
• Tuomas Lönnberg and
• Harri Lönnberg

Beilstein J. Org. Chem. 2018, 14, 803–837, doi:10.3762/bjoc.14.68

• observed, but only the cleavage was subject to buffer catalysis, viz. general base catalysis. In aqueous solution, second-order dependence of rate on buffer concentration has never been reported. Besides imidazole, guanidine and primary amines have received special interest as cleaving agents of RNA [69

• transfer from the attacking 2´-OH to non-bridging phosphoryl oxygen. Primary amines are, in turn, used to mimic the action of the ε-amino group of lysine. Both guanidine and primary amino groups are basic functions that at physiological pH are present as guanidinium and ammonium ions. These ions tend to

Diastereoselective auxiliary- and catalyst-controlled intramolecular aza-Michael reaction for the elaboration of enantioenriched 3-substituted isoindolinones. Application to the synthesis of a new pazinaclone analogue

• Romain Sallio,
• Stéphane Lebrun,
• Frédéric Capet,
• Francine Agbossou-Niedercorn,
• Christophe Michon and
• Eric Deniau

Beilstein J. Org. Chem. 2018, 14, 593–602, doi:10.3762/bjoc.14.46

• treatment with trifluoroacetic acid to provide in-situ the corresponding benzoic acids 14a–e and 15. The direct coupling of these functionalized carboxylic acids with chiral benzylic primary amines, (R) or (S)-16 (NH2-CH(Me)Ph) and (R)-17 (NH2CH(Me)p-MeO-C6H4), afforded the required parent amides 6a–d, 7a–e

Progress in copper-catalyzed trifluoromethylation

• Guan-bao Li,
• Chao Zhang,
• Chun Song and
• Yu-dao Ma

Beilstein J. Org. Chem. 2018, 14, 155–181, doi:10.3762/bjoc.14.11

• )–H with a electrophilic trifluoromethylation reagent (Togni’s reagent): N,N-Dialkylhydrazones were widely used in organic chemistry, including using as synthetic equivalents of carbonyl compounds, as precursors to substituted hydrazines or primary amines. In 2013, Baudoin and co-workers [53] firstly

Quinone-catalyzed oxidative deformylation: synthesis of imines from amino alcohols

• Xinyun Liu,
• Johnny H. Phan,
• Benjamin J. Haugeberg,
• Shrikant S. Londhe and
• Michael D. Clift

Beilstein J. Org. Chem. 2017, 13, 2895–2901, doi:10.3762/bjoc.13.282

• -catalyzed oxidative deformylation of 1,2-amino alcohols is reported. A wide range of readily accessible amino alcohols and primary amines can be reacted to provide N-protected imine products. The methodology presented provides a novel organocatalytic approach for imine synthesis and demonstrates the

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF₃SO₂Na

• Hélène Guyon,
• Hélène Chachignon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

One-pot three-component route for the synthesis of S-trifluoromethyl dithiocarbamates using Togni’s reagent

• Azim Ziyaei Halimehjani,
• Martin Dračínský and
• Petr Beier

Beilstein J. Org. Chem. 2017, 13, 2502–2508, doi:10.3762/bjoc.13.247

• rather than an electrophilic trifluoromethylating reagent (Scheme 3). A similar behavior was recently reported by Schoenebeck [37] who showed that isothiocyanates are formed in reactions of primary amines with the (Me4N)SCF3 salt (through a different mechanism). Interesting differences in the NMR spectra

One-pot syntheses of blue-luminescent 4-aryl-1H-benzo[f]isoindole-1,3(2H)-diones by T3P^® activation of 3-arylpropiolic acids

• Melanie Denißen,
• Alexander Kraus,
• Guido J. Reiss and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2017, 13, 2340–2351, doi:10.3762/bjoc.13.231

• , leaving the anhydride unimpaired. For employing 4-phenylnaphtho[2,3-c]furan-1,3-diones 2 as reactive intermediates for the en route conversion with primary amines 3 into 4-aryl-1H-benzo[f]isoindole-1,3(2H)-diones 4 the reaction conditions were optimized with 4-phenylnaphtho[2,3-c]furan-1,3-dione (2a) and

• be readily activated with T3P® (n-propylphosphonic acid anhydride) to initiate a domino reaction furnishing 4-arylnaphtho[2,3-c]furan-1,3-diones in excellent yields. These anhydrides can be considered as reactive intermediates for a subsequent imidation with primary amines and, therefore, a one-pot

Dialkyl dicyanofumarates and dicyanomaleates as versatile building blocks for synthetic organic chemistry and mechanistic studies

• Grzegorz Mlostoń and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 2235–2251, doi:10.3762/bjoc.13.221

• yields. The X-ray analysis showed that products 53 obtained with primary amines are Z-configured whereas those derived from secondary amines, 54, display E-configuration [58] (Scheme 18). The observed different configurations demonstrate the importance of the intramolecular hydrogen-bond between the NH

High-speed vibration-milling-promoted synthesis of symmetrical frameworks containing two or three pyrrole units

• Marco Leonardi,
• Mercedes Villacampa and
• J. Carlos Menéndez

Beilstein J. Org. Chem. 2017, 13, 1957–1962, doi:10.3762/bjoc.13.190

• approaches to organic and inorganic synthesis [4][5][6][7][8][9][10][11][12][13]. Indeed, the protocol reported here can be viewed as a generalization of our previously published pyrrole synthesis based on the reaction between primary amines, β-dicarbonyl compounds and ketones, promoted by high-speed

Mechanochemical N-alkylation of imides

• Anamarija Briš,
• Mateja Đud and
• Davor Margetić

Beilstein J. Org. Chem. 2017, 13, 1745–1752, doi:10.3762/bjoc.13.169

• equimolar amount of ethyl bromide resulted in the dominant formation of the mono-alkylated 1-ethyl product 38. The N-alkylated phthalimides 23 and 24, which were prepared in the previous section were employed in solvent-free Gabriel synthesis of primary amines (Scheme 4). In these milling reactions, the

1-Imidoalkylphosphonium salts with modulated C_α–P⁺ bond strength: synthesis and application as new active α-imidoalkylating agents

• Jakub Adamek,
• Roman Mazurkiewicz,
• Anna Węgrzyk and
• Karol Erfurt

Beilstein J. Org. Chem. 2017, 13, 1446–1455, doi:10.3762/bjoc.13.142

• -imidoalkylphosphonium salts 5 applied in the Tscherniac–Einhorn-type reaction with aromatic hydrocarbons as a model reaction. The obtained N-(1-arylalkyl)imides can easily be transformed to the corresponding primary 1-arylalkylamines, following the well-known procedures developed for the Gabriel synthesis of primary

• amines. Moreover, this class of compounds is itself attracting significant attention from chemists and biochemists due to their bioactivity as herbicides, and anticancer, anti-inflammatory, analgesic or anticonvulsant agents [26][27][28][29][30][31]. Especially interesting is apremilast (brand name

Sustainable synthesis of 3-substituted phthalides via a catalytic one-pot cascade strategy from 2-formylbenzoic acid with β-keto acids in glycerol

• Lina Jia and
• Fuzhong Han

Beilstein J. Org. Chem. 2017, 13, 1425–1429, doi:10.3762/bjoc.13.139

• efficiency of the reaction, a detailed optimization study was performed with various bases, such as tertiary, secondary and primary amines. When tertiary amines were used as the catalyst, very low yields of 3a were obtained (Table 1, entries 3–5). Unfortunately, a sluggish reaction was observed in the

• presence of pyrrolidine (Table 1, entry 6). Gratifyingly, the desired product was obtained in the presence of primary amines in good yields (Table 1, entries 7–9). In addition, the use of several inorganic bases delivered no catalytic activation (Table 1, entries 10 and 11). Notably, a higher reaction

New tricks of well-known aminoazoles in isocyanide-based multicomponent reactions and antibacterial activity of the compounds synthesized

• Maryna V. Murlykina,
• Maryna N. Kornet,
• Sergey M. Desenko,
• Svetlana V. Shishkina,
• Oleg V. Shishkin,
• Aleksander A. Brazhko,
• Vladimir I. Musatov,
• Erik V. Van der Eycken and
• Valentin A. Chebanov

Beilstein J. Org. Chem. 2017, 13, 1050–1063, doi:10.3762/bjoc.13.104

• exocyclic NH2 group and an endocyclic nucleophilic center, they can act both as primary amines and as 1,3-binucleophiles, therefore, their treatments with isocyanides, aldehydes and carboxylic acids may proceed either as Ugi-4CR (aminoazole – primary amine, acid – reagent) or as GBB-3CR (aminoazole – 1,3

• primary amines that allowed using it as an amine component in Ugi-4CR. Particularly, its reaction with aromatic aldehydes 1a–h, phenylpropiolic acid (8) and tert-butylisocyanide (3a) gave peptidomimetics 9 under stirring the starting reagents in MeOH at room temperature for 24 h. In the presence of strong

DMAP-assisted sulfonylation as an efficient step for the methylation of primary amine motifs on solid support

• Johnny N. Naoum,
• Koushik Chandra,
• Dorit Shemesh,
• R. Benny Gerber,
• Chaim Gilon and
• Mattan Hurevich

Beilstein J. Org. Chem. 2017, 13, 806–816, doi:10.3762/bjoc.13.81

• of over-methylated amines. The Mitsunobu–Fukuyama reaction was used for the conversion of primary amines to secondary mono-methylated amines in solution using an alcohol and via temporary protection of the amino group to avoid over methylation [17][18][19][20][21]. This method relies on the

• introduction of the o- or p-nitrobenzenesulfonyl groups to primary amines in the first step. The semi-protected sulfonamides can then undergo a selective mono-methylation via Mitsunobu reaction or by direct methylation. The reaction is completed by the selective removal of the sulfonamide group. Miller and

• additive for sulfonylation of primary amines with o-NBS-Cl for the purpose of N-methylation on solid support. We herein report a DMAP-mediated strategy for the efficient regioselective N-methylation of sterically hindered primary amines as well as less hindered amines on solid support (Figure 1B). Our DFT

Pd- and Cu-catalyzed approaches in the syntheses of new cholane aminoanthraquinone pincer-like ligands

• Nikolay V. Lukashev,
• Gennadii A. Grabovyi,
• Dmitry A. Erzunov,
• Alexey V. Kazantsev,
• Gennadij V. Latyshev,
• Alexei D. Averin and
• Irina P. Beletskaya.

Beilstein J. Org. Chem. 2017, 13, 564–570, doi:10.3762/bjoc.13.55

• LiAlH4 (Scheme 2) [37]. Cu-catalyzed amination is known to be a very efficient approach for C–N bond formation [38][39]. The availability of the variety of inexpensive ligands for copper(I) is a crucial benefit in comparison to the Pd-catalyzed variant. Primary amines of different structures can readily

Effect of the ortho-hydroxy group of salicylaldehyde in the A³ coupling reaction: A metal-catalyst-free synthesis of propargylamine

• Sujit Ghosh,
• Kinkar Biswas,
• Suchandra Bhattacharya,
• Pranab Ghosh and
• Basudeb Basu

Beilstein J. Org. Chem. 2017, 13, 552–557, doi:10.3762/bjoc.13.53

• . Furthermore, reactions with primary amines like cyclohexylamine and benzylamine produce only the imine and no A3-coupled product, signifying that imines are less efficient than iminium species to initiate further reaction with terminal alkyne. Conclusion In conclusion, the present study demonstrates an