Copper–phenanthroline catalysts for regioselective synthesis of pyrrolo[3′,4′:3,4]pyrrolo[1,2-a]furoquinolines/phenanthrolines and of pyrrolo[1,2-a]phenanthrolines under mild conditions

• Rupankar Paira,
• Tarique Anwar,
• Maitreyee Banerjee,
• Yogesh P. Bharitkar,
• Shyamal Mondal,
• Sandip Kundu,
• Abhijit Hazra,
• Prakas R. Maulik and
• Nirup B. Mondal

Beilstein J. Org. Chem. 2014, 10, 692–700, doi:10.3762/bjoc.10.62

• studies started with the preparation (Scheme 1 and Scheme 2) of maleimides 4a–c employing maleic anhydride (1) and different aromatic amines 2a–c, and of furo[3,2-h]quinoliniums 9a–d from 5-chloro-8-hydroxy-7-iodoquinoline 5 [19][24]. However, attempted condensation of 4a with the 1,3-dipole generated in

Isocyanide-based multicomponent reactions towards cyclic constrained peptidomimetics

• Gijs Koopmanschap,
• Eelco Ruijter and
• Romano V.A. Orru

Beilstein J. Org. Chem. 2014, 10, 544–598, doi:10.3762/bjoc.10.50

• also explored with several aliphatic and aromatic amines, in which the more electron-rich inputs gave the higher yields. In a variation, first the triazole-unit was formed followed by the Ugi MCR. However this resulted in lower yields compared to the initial sequence (33–39% vs. 31–61%). Pyrazoles and

Silver and gold-catalyzed multicomponent reactions

• Giorgio Abbiati and
• Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

• secondary amines, as well as aryl and alkyl-substituted alkynes (Scheme 2). It is noteworthy that the approach tolerated challenging substrates such as formaldehyde, o-substituted benzaldehydes, and secondary aromatic amines. Moreover, the PS–NHC–Ag(I) catalyst was proven to be reusable at least 12 times

Synthesis, characterization and luminescence studies of gold(I)–NHC amide complexes

• Adrián Gómez-Suárez,
• David J. Nelson,
• David G. Thompson,
• David B. Cordes,
• Duncan Graham,
• Alexandra M. Z. Slawin and
• Steven P. Nolan

Beilstein J. Org. Chem. 2013, 9, 2216–2223, doi:10.3762/bjoc.9.260

• = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) with a series of commercially available (hetero)aromatic amines leads to the synthesis of several [Au(NRR’)(IPr)] complexes in good yields and with water as the sole byproduct. Interestingly, these complexes present luminescence properties. UV–vis and

• deprotonation reactions with this building block, limited to substrates with a pKa lower than 30. Encouraged by these exploratory reactions, a series of (hetero)aromatic amines were employed to prepare the corresponding gold(I)–amide complexes. The desired complexes were obtained by reaction of [Au(OH)(IPr)] (1

• ) with each (hetero)aromatic amine in THF at room temperature for 20 h. A range of aromatic amines were employed, including aniline, diphenylamine, pyridines, a pyrimidine and one isoquinoline. The corresponding complexes were obtained in analytically pure form and in good yields as yellow or white

The chemistry of amine radical cations produced by visible light photoredox catalysis

• Jie Hu,
• Jiang Wang,
• Theresa H. Nguyen and
• Nan Zheng

Beilstein J. Org. Chem. 2013, 9, 1977–2001, doi:10.3762/bjoc.9.234

• provides an indirect approach for α-C–H functionalization of N-aryltetrahydroquinolines and N-arylindolines. Based on the feasibility of oxidation of aromatic amines as well as reduction of di-tert-butyl azodicarboxylate (110) by the photoexcited Ir(III) complex [98][99], the authors favored a mechanism

• limited by the substrate scope of the amine precursors, since aromatic amines are typically required (vide supra). The cleavage reaction, as demonstrated by Li and Wang’s work, has the potential to produce different types of iminium ions and α-amino radicals that are not accessible by oxidizing amines

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

A study on electrospray mass spectrometry of fullerenol C₆₀(OH)₂₄

• Mihaela Silion,
• Andrei Dascalu,
• Mariana Pinteala,
• Bogdan C. Simionescu and
• Cezar Ungurenasu

Beilstein J. Org. Chem. 2013, 9, 1285–1295, doi:10.3762/bjoc.9.145

• on pristine fullerene anion radicals [34][35][36][37] unquestionably confirmed their generation by electron transfer from various electron donors (aliphatic and aromatic amines especially) [38][39], one can postulate that, under ESI conditions, a distonic radical carbanion [(C60(OH)24−•)2]2−• is

Mild and efficient cyanuric chloride catalyzed Pictet–Spengler reaction

• Ashish Sharma,
• Mrityunjay Singh,
• Nitya Nand Rai and
• Devesh Sawant

Beilstein J. Org. Chem. 2013, 9, 1235–1242, doi:10.3762/bjoc.9.140

• tryptamine (1), by aromatic amines [11]. Moreover, the aromatic amines can be originated from either carbon or nitrogen of the activated heterocycle. Hence, these substrates are referred to as “modified Pictet–Spengler substrates”. We employed one of the arylamine substrates for our studies (Figure 1). 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

• of 3-[18F]fluoropropyl thiocyanate to the corresponding sulfonyl chloride with the potential for automation have been identified. The reaction of 3-[18F]fluoropropanesulfonyl chloride with eight different aliphatic and aromatic amines was investigated and the identity of the resulting 18F-labelled

• and to study its reaction with a panel of aliphatic and aromatic amines of varying reactivity. Particular attention was paid to the synthesis of precursor molecules suitable for radiofluorination and nonradioactive reference compounds, as the information published in [18] is rather preliminary in this

• regard. Furthermore, we aimed to extend 18F-fluoropropanesulfonylation to the labelling of aromatic amines. Additionally, the metabolic stability of 3-fluoropropanesulfonamides was proven and comparatively assessed to that of analogous fluoroacetamides by degradation experiments with carboxylesterase

Polymerization of novel methacrylated anthraquinone dyes

• Christian Dollendorf,
• Susanne Katharina Kreth,
• Soo Whan Choi and
• Helmut Ritter

Beilstein J. Org. Chem. 2013, 9, 453–459, doi:10.3762/bjoc.9.48

• monomeric dye 9 with non-aromatic amines as functional moieties, which showed similar properties, was also synthesized starting from anthraquinone. 1,1-Dimethyl-2-hydroxyethylamine exhibits two methyl groups in the α-position to the nitrogen atom, which shields the chromophoric amine. The absence of

• -products derived from ring-closure reactions were only found when aliphatic amines with two carbon units between the amine and hydroxy functionality were used. In the synthesis of green and blue dyes, aromatic amines that cannot build six-membered rings were utilized. However, the ring-closure can be

Palladium-catalyzed C–N and C–O bond formation of N-substituted 4-bromo-7-azaindoles with amides, amines, amino acid esters and phenols

• Rajendra Surasani,
• Dipak Kalita,
• A. V. Dhanunjaya Rao and
• K. B. Chandrasekhar

Beilstein J. Org. Chem. 2012, 8, 2004–2018, doi:10.3762/bjoc.8.227

• reaction of primary aromatic amines (Table 4, entries 3, 4 and 6) proceeded smoothly under the optimized conditions to provide excellent yields of the corresponding coupling products 5a, 5b and 5d, respectively. The reaction was also effective for cyclic amine morpholine (Table 4, entry 5) and Boc

Synthesis and anion recognition properties of shape-persistent binaphthyl-containing chiral macrocyclic amides

• Marco Caricato,
• Nerea Jordana Leza,
• Claudia Gargiulli,
• Giuseppe Gattuso,
• Daniele Dondi and
• Dario Pasini

Beilstein J. Org. Chem. 2012, 8, 967–976, doi:10.3762/bjoc.8.109

• , we set out to exploit two orthogonal synthetic strategies (Figure 1, bottom): (1) A direct amidation of the carboxylic acids in the 3,3' positions, in the presence of the free phenolic oxygens in the 2,2' positions. Literature precedents for such amidation using aromatic amines in the presence of

• vicinal phenol moieties (which compete since they are comparable in nucleophilicity with aromatic amines) are rare [32][33]. As already reported [31], test reactions on model compounds gave disappointing results. The use of benzylic amines, more nucleophilic than arylamines, and therefore competing less

• protecting groups, since its synthesis has been reported, and the deprotection of these groups usually occurs under mild basic conditions [34]. Aromatic amines, as in (R,R)-1, could in principle be used. Preliminary synthetic work was performed on model compounds to test the reaction conditions. Both

Enaminones in a multicomponent synthesis of 4-aryldihydropyridines for potential applications in photoinduced intramolecular electron-transfer systems

• Nouria A. Al-Awadi,
• Maher R. Ibrahim,
• Mohamed H. Elnagdi,
• Elizabeth John and
• Yehia A. Ibrahim

Beilstein J. Org. Chem. 2012, 8, 441–447, doi:10.3762/bjoc.8.50

• /aromatic amines, ethyl propiolate and benzaldehyde [14], or by a cascade reaction of 1-phenylpropynone or ethyl propiolate with primary amines and aldehyde [15]. Enaminones are versatile starting materials for the synthesis of many classes of organic compounds and heterocyclic systems [16][17], and are

Double N-arylation reaction of polyhalogenated 4,4’-bipyridines. Expedious synthesis of functionalized 2,7-diazacarbazoles

• Mohamed Abboud,
• Emmanuel Aubert and
• Victor Mamane

Beilstein J. Org. Chem. 2012, 8, 253–258, doi:10.3762/bjoc.8.26

• scope and limitations of the Pd2(dba)3–XPhos catalyst system (Table 1). Under the standard conditions summarized in Table 1 (footnote a), the double N-arylation of 2a with various aromatic amines 6 furnished 2,7-diazacarbazoles 3 with good chemoselectivities. Moderate to good yields were generally

• 2a. Functionalized diazacarbazoles 12a–c from bipyridine 2b. Double N-arylation of 2a with aromatic amines 6 catalyzed by a palladium–XPhos complex.a Supporting Information Supporting Information File 48: Characterization data and NMR spectra of all compounds, including X-ray structure determination

Recent advances in the gold-catalyzed additions to C–C multiple bonds

• He Huang,
• Yu Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2011, 7, 897–936, doi:10.3762/bjoc.7.103

• catalytic addition of a nitrogen nucleophile to a C–C multiple bond represents an attractive approach to the formation of C–N bonds [55]. This is a direct and efficient procedure for the synthesis of nitrogen containing compounds of industrial importance. 3.1 Alkyl- and aromatic amines as nucleophiles

Approaches towards the synthesis of 5-aminopyrazoles

• Ranjana Aggarwal,
• Vinod Kumar,
• Rajiv Kumar and
• Shiv P. Singh

Beilstein J. Org. Chem. 2011, 7, 179–197, doi:10.3762/bjoc.7.25

• the alkylthio group by the unsubstituted nitrogen of the hydrazine. The reaction of bis(methylthio)methylenecyanoacetamide 86 (R = CH3, X = CONH2) with aromatic amines gave the corresponding 3-N-substituted aminoacrylamides 89, which on further treatment with phenylhydrazine furnished the

Palladium- and copper-mediated N-aryl bond formation reactions for the synthesis of biological active compounds

• Carolin Fischer and
• Burkhard Koenig

Beilstein J. Org. Chem. 2011, 7, 59–74, doi:10.3762/bjoc.7.10

• Carolin Fischer Burkhard Koenig Institute of Organic Chemistry, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany 10.3762/bjoc.7.10 Abstract N-Arylated aliphatic and aromatic amines are important substituents in many biologically active compounds. In the last few years

• (Scheme 13). The method benefits from controlled regiochemistry and is applicable to various aliphatic and aromatic amines 58. Although the reaction scope was limited to 1-bromo-2-iodobenzenes 59, scale-up to multigram quantities was possible [65]. A key intermediate 64 of imatinib 61, a standard anti

A new and facile synthetic approach to substituted 2-thioxoquinazolin-4-ones by the annulation of a pyrimidine derivative

• Nimalini D. Moirangthem and
• Warjeet S. Laitonjam

Beilstein J. Org. Chem. 2010, 6, 1056–1060, doi:10.3762/bjoc.6.120

• approach involves briefly heating 2-(methylcarboxy)-benzeneisothiocyanates in isopropyl alcohol with a wide variety of primary aliphatic or aromatic amines and their derivatives. Thus, most of the methods for the preparation of such compounds start with the benzene ring in place followed by construction of

EPR and pulsed ENDOR study of intermediates from reactions of aromatic azides with group 13 metal trichlorides

• Giorgio Bencivenni,
• Riccardo Cesari,
• Daniele Nanni,
• Hassane El Mkami and
• John C. Walton

Beilstein J. Org. Chem. 2010, 6, 713–725, doi:10.3762/bjoc.6.84

• the degree of protonation, which can facilitate electron transfer (ET) [39][40]. It has also been reported that electrochemical oxidation of aromatic amines can generate the same radical cations which can polymerise giving oligo- and poly-anilines [41]. In view of the fact that product analyses [31

• ] identified aniline amongst the products from 1 and anisole amongst the products from 2, it seems probable that the aromatic amines are the precursors of the dimer and trimer species. A possible mechanism for production of anilines from the aromatic azides is set out in Scheme 4. Coordination of the metal

• arrow indicating the magnetic field position of the ENDOR experiment. DFT structures and SOMOs for dimer and trimer radical cations. Organic azides studied. Reaction of 4-substituted-phenyl azides with GaCl3. Dimer and trimer radical cations. Possible mechanism of formation of aromatic amines. Possible

Molecular recognition of organic ammonium ions in solution using synthetic receptors

• Andreas Späth and
• Burkhard König

Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32

Synthesis of (S)-1-(2-chloroacetyl)pyrrolidine- 2-carbonitrile: A key intermediate for dipeptidyl peptidase IV inhibitors

• Santosh K. Singh,
• Narendra Manne and
• Manojit Pal

Beilstein J. Org. Chem. 2008, 4, No. 20, doi:10.3762/bjoc.4.20

• solution. The spectral data of compound 6 were identical to the reported data [6]. Having prepared the key intermediate 6 successfully we treated it with a variety of aliphatic and aromatic amines to generate a library of compounds for biological screening. Moreover, the DPP-IV inhibitor Vildagliptin or