Palladium-catalyzed synthesis of N-arylated carbazoles using anilines and cyclic diaryliodonium salts

• Stefan Riedmüller and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2013, 9, 1202–1209, doi:10.3762/bjoc.9.136

• when benzylamine (2c) was used (41% yield). Even more electron-donating aniline derivatives, such as p-anisidine (p-methoxyaniline), resulted in the formation of trace amounts of the carbazole product (not shown). The aliphatic primary amines tert-butylamine (2d) and propylamine (2e) were also

Amyloid-β probes: Review of structure–activity and brain-kinetics relationships

• Todd J. Eckroat,
• Abdelrahman S. Mayhoub and
• Sylvie Garneau-Tsodikova

Beilstein J. Org. Chem. 2013, 9, 1012–1044, doi:10.3762/bjoc.9.116

• that the more lipophilic secondary and tertiary amines at the 4'-position were more potent (Ki) than primary amines. Also, in general, substitution at the 6-position seemed to have only a small effect in terms of Ki as 6-OH, -OCH3, -CN, and -Br gave similar results. However, substitution at the 6

3D-printed devices for continuous-flow organic chemistry

• Vincenza Dragone,
• Victor Sans,
• Mali H. Rosnes,
• Philip J. Kitson and
• Leroy Cronin

Beilstein J. Org. Chem. 2013, 9, 951–959, doi:10.3762/bjoc.9.109

• of aldehydes and primary amines. Secondly, two reactors were connected in series to first perform an imine synthesis and then subsequently an imine reduction, with this second setup showing the potential for using the 3D-printed devices as reliable tools in multistep synthesis. This showed that the

• -valves. Flow system setup, where a R1 is connected to the syringe pumps and the ATR-IR flow cell with standard connectors. Carbonyl compounds and primary amines used in the syntheses reported in this work. Carbonyl compounds: benzaldehyde (1a); R-(−)-myrtenal (1b); 3-pentanone (1c). Aniline derivatives

Synthesis of functionalized spiro[indoline-3,4’-pyridines] and spiro[indoline-3,4’-pyridinones] via one-pot four-component reactions

• Li-Juan Zhang,
• Qun Wu,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2013, 9, 846–851, doi:10.3762/bjoc.9.97

• arylamines and other primary amines. Keywords: 1,4-dihydropyridine; electron-deficient alkyne; four-component reaction; isatin; one-pot reaction; spiro compound; Introduction β-Enaminones and β-enamino esters represent important synthetic building blocks for the development of versatile carbon–carbon bond

• -formation reactions and heterocyclic constructions [1][2][3][4][5]. In recent years, the in situ generated β-enamino esters, which could be easily obtained from the addition of aliphatic or aromatic primary amines to the activated alkynes, have been widely recognized as practical synthons for the synthesis

Some aspects of radical chemistry in the assembly of complex molecular architectures

• Béatrice Quiclet-Sire and
• Samir Z. Zard

Beilstein J. Org. Chem. 2013, 9, 557–576, doi:10.3762/bjoc.9.61

• 1,4-keto-aldehyde and, in this capacity, can react with ammonia or primary amines, such as cyclopropylamine, to produce the corresponding pyrrole 113 by what may be viewed as a variation of the classical Paal–Knorr synthesis [47][48]. Xanthate 107 is a highly versatile reagent, since it allows the

• replaced with various primary amines, one example being cyclopropylamine, which furnishes piperidine 129 as one stereoisomer. In the case of 1,2-diaminoethane, a further cyclisation is observed leading to bicyclic piperidine 130. All three components involved in this modular approach can be modified to

The chemistry of bisallenes

• Henning Hopf and
• Georgios Markopoulos

Beilstein J. Org. Chem. 2012, 8, 1936–1998, doi:10.3762/bjoc.8.225

Synthesis of conformationally restricted glutamate and glutamine derivatives from carbonylation of orthopalladated phenylglycine derivatives

• Esteban P. Urriolabeitia,
• Eduardo Laga and
• Carlos Cativiela

Beilstein J. Org. Chem. 2012, 8, 1569–1575, doi:10.3762/bjoc.8.179

• presence of additional nucleophiles, since the cyclization generates an isoindolinonium salt, from which it is relatively easy to promote a simple deprotonation. Very interestingly, the reactivity of 1 is not limited to the addition of alcohols, and primary amines, secondary amines, and even α-aminoesters

Organocatalytic C–H activation reactions

• Subhas Chandra Pan

Beilstein J. Org. Chem. 2012, 8, 1374–1384, doi:10.3762/bjoc.8.159

• ]. One well-known example of the “tert-amino effect” is the cyclization of N,N-dialkyl-substituted anilines with imines to generate cyclic aminals. The groups of Seidel and Akiyama independently reported mild organocatalytic approaches to cyclic aminals involving aminobenzaldehydes and primary amines [10

Palladium-catalyzed substitution of (coumarinyl)methyl acetates with C-, N-, and S-nucleophiles

• Kalicharan Chattopadhyay,
• Erik Fenster,
• Alexander J. Grenning and
• Jon A. Tunge

Beilstein J. Org. Chem. 2012, 8, 1200–1207, doi:10.3762/bjoc.8.133

• partners (Scheme 6). Primary amines were also compatible coupling partners, although under these conditions, the reaction never went to full conversion (5i–k). As mentioned previously, we were devising this approach to coumarin substitution not only for the sake of new chemical methodology, but also

Enantioselective supramolecular devices in the gas phase. Resorcin[4]arene as a model system

• Caterina Fraschetti,
• Matthias C. Letzel,
• Antonello Filippi,
• Maurizio Speranza and
• Jochen Mattay

Beilstein J. Org. Chem. 2012, 8, 539–550, doi:10.3762/bjoc.8.62

• the effect of the mentioned source of asymmetry by generating, in a nanoESI-FT-ICR mass spectrometer, proton-bound complexes between resorcinarenes C (Figure 10) [57] and several polyfunctionalized biomolecules (G, Table 4), and then by measuring their gas-phase reactivity towards some primary amines

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

• Nouria A. Al-Awadi Maher R. Ibrahim Mohamed H. Elnagdi Elizabeth John Yehia A. Ibrahim Chemistry Department, Faculty of Science, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait 10.3762/bjoc.8.50 Abstract An efficient three component reaction with enaminones, primary amines and aldehydes

• resulted in easy access to 1,4-dihydropyridines with different substituents at the 1-, 3-, 4- and 5-positions. Microwaves improved the reaction yield, reducing also considerably the reaction time and the amount of solvent used. Chiral primary amines gave chiral 1-substituted-1,4-dihydropyridines. The 4-(1

• /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

Derivatives of phenyl tribromomethyl sulfone as novel compounds with potential pesticidal activity

• Krzysztof M. Borys,
• Maciej D. Korzyński and
• Zbigniew Ochal

Beilstein J. Org. Chem. 2012, 8, 259–265, doi:10.3762/bjoc.8.27

• aliphatic amines (products 7c–7h), aromatic primary amines (products 7i–7k) and phenols (products 7l–7o), with all the resulting compounds being obtained in >85% yields (Table 1; see Supporting Information File 1 for further details on products 7a–7o). At this point, two groups of the designed target

A general and facile one-pot process of isothiocyanates from amines under aqueous conditions

• Nan Sun,
• Bin Li,
• Jianping Shao,
• Weimin Mo,
• Baoxiang Hu,
• Zhenlu Shen and
• Xinquan Hu

Beilstein J. Org. Chem. 2012, 8, 61–70, doi:10.3762/bjoc.8.6

• Academy of Sciences, Lanzhou 730000, China 10.3762/bjoc.8.6 Abstract A general and facile one-pot protocol for the preparation of a broad range of alkyl and aryl isothiocyanates has been developed from their corresponding primary amines under aqueous conditions. This synthetic process involves an in situ

• particularly for highly electron-deficient substrates. This novel and economical method is suitable for scale-up activities. Keywords: aqueous conditions; cyanuric acid; isothiocyanates; one-pot process; organic synthesis; primary amines; Introduction Isothiocyanates are a class of heteroallenic compounds

Synthesis of 2-amino-3-arylpropan-1-ols and 1-(2,3-diaminopropyl)-1,2,3-triazoles and evaluation of their antimalarial activity

• Matthias D’hooghe,
• Stéphanie Vandekerckhove,
• Karen Mollet,
• Karel Vervisch,
• Stijn Dekeukeleire,
• Liesbeth Lehoucq,
• Carmen Lategan,
• Peter J. Smith,
• Kelly Chibale and
• Norbert De Kimpe

Beilstein J. Org. Chem. 2011, 7, 1745–1752, doi:10.3762/bjoc.7.205

• prepared by treatment of N-(arylmethylidene)alkylamines (synthesized in high yields through condensation of the corresponding benzaldehydes with the appropriate primary amines in CH2Cl2 in the presence of anhydrous MgSO4) with 1.5 equiv of chloroacetyl chloride and 3 equiv of 2,6-lutidine in benzene

Amines as key building blocks in Pd-assisted multicomponent processes

• Didier Bouyssi,
• Nuno Monteiro and
• Geneviève Balme

Beilstein J. Org. Chem. 2011, 7, 1387–1406, doi:10.3762/bjoc.7.163

• sulfur dioxide. However, this Pd-catalyzed aminosulfonylation process proved inefficient with primary amines (Scheme 20) [20]. Multicomponent synthesis of nitrogen-containing heterocycles may also be initiated by an aza-Michael addition and terminated by a palladium-catalyzed ring-closure process [21

• Pd-catalyzed cross-coupling approach starting from 1-chloro-2-iodobenzenes, phenylacetylene and a variety of primary amines [28][29]. The sequential three-component reaction was performed with the aid of an N-heterocyclic carbene-palladium complex generated in situ, derived from imidazolium salt 50

• phenothiazine derivatives 72 starting from primary amines, 2-bromothiophenol and substituted 1-bromo-2-iodobenzenes [40]. Ferrocene ligands, such as dppf, and Pd2dba3 as the palladium source were found to be the most suitable and efficient catalyst systems for the preparation of a series of phenotiazine

Reductive amination with zinc powder in aqueous media

• Giovanni B. Giovenzana,
• Daniela Imperio,
• Andrea Penoni and
• Giovanni Palmisano

Beilstein J. Org. Chem. 2011, 7, 1095–1099, doi:10.3762/bjoc.7.125

• , Via Valleggio 11, I-22100 Como, Italy; Fax: +39-(0)31-2386449, Tel: +39-(0)31-2386234 10.3762/bjoc.7.125 Abstract Zinc powder in aqueous alkaline media was employed to perform reductive amination of aldehydes with primary amines. The corresponding secondary amines were obtained in good yields along

• . No difference in the reducing activity was noted in two reactions run with such recycled zinc powder. The scope of the reaction was assessed using different combinations of aldehydes and primary amines (Table 1). In the first entries, benzylamine was chosen and fixed as the amine component, then

• phenolic hydroxy groups. The list illustrates the significant applicability of this one-pot zinc-mediated reductive amination. Nevertheless the protocol showed some limitations with selected substrates: i) Secondary amines failed to give tertiary amines; ii) hindered primary amines (e.g., tert-butylamine

Microphotochemistry: 4,4'-Dimethoxybenzophenone mediated photodecarboxylation reactions involving phthalimides

• Oksana Shvydkiv,
• Kieran Nolan and
• Michael Oelgemöller

Beilstein J. Org. Chem. 2011, 7, 1055–1063, doi:10.3762/bjoc.7.121

• -Photodecarboxylation of N-phthaloylglycine The photodecarboxylation of phthaloyl amino acids results in a formal exchange of –CO2H by –H and offers a convenient pathway to primary amines [40]. The reaction of N-phthaloylglycine (1) in acetonitrile using 0.1 equivalents of DMBP as a mediator was thus investigated as an

A practical route to tertiary diarylmethylamides or -carbamates from imines, organozinc reagents and acyl chlorides or chloroformates

• Erwan Le Gall,
• Antoine Pignon and
• Thierry Martens

Beilstein J. Org. Chem. 2011, 7, 997–1002, doi:10.3762/bjoc.7.112

• and aldehydes to furnish tertiary diarylmethylamines [28][29][30][31][32][33]. However, while a large range of starting compounds could be used successfully in the process, we noticed that primary amines are ineffective, probably due to a weaker electrophilicity of the in situ-formed imines compared

• to iminium ions. Consequently, we report herein the use of primary amines in a sequential one-pot process, based on the preliminary activation of an aldimine with an acyl chloride or a chloroformate, and the subsequent trapping of the resulting acyliminium ion with an aromatic organozinc reagent, to

• -substituted aldimines, formed in situ upon reaction of primary amines with aromatic aldehydes, cannot be undertaken under our established conditions. Thus, we intended to activate the C=N double bond by rendering the carbon more electrophilic and we initially envisaged the use of Lewis acid catalysis. Indeed

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

• primary amines is an important reaction in organic synthesis. He et al. developed an efficient gold-catalyzed one-pot selective N-alkylation of amines with alcohols [57]. In their study, gold nanoparticles supported on titania act as an efficient heterogeneous catalyst for the reaction to give the N

Formation of epoxide-amine oligo-adducts as OH-functionalized initiators for the ring-opening polymerization of ε-caprolactone

• Julia Theis and
• Helmut Ritter

Beilstein J. Org. Chem. 2010, 6, 938–944, doi:10.3762/bjoc.6.105

• , the addition polymerization of primary amines with diepoxides forming linear adducts has been intensively studied [21]. Linear epoxide-amine addition polymers can be obtained for instance by the addition reaction of diglycidyl ethers and aromatic primary amines in equimolar amounts. With regard to our

Development of dynamic kinetic resolution on large scale for (±)-1-phenylethylamine

• Lisa K. Thalén and
• Jan-E. Bäckvall

Beilstein J. Org. Chem. 2010, 6, 823–829, doi:10.3762/bjoc.6.97

• product mixture. However, by racemizing the slower reacting enantiomer in situ, in a process known as dynamic kinetic resolution (DKR) [11], a theoretical yield of 100% can be achieved. We have previously developed a highly efficient protocol for the DKR of primary amines using Candida antarctica lipase B

• uncatalyzed chemical acylation of the substrate occurs at elevated temperatures when using acyl donors of this type in the DKR of primary amines. This has been overcome by initially adding one equivalent of the acyl donor followed by a later addition of 0.1 equiv of the acyl donor to allow the reaction to go

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 3-(phenylazo)-1,2,4-triazoles by a nucleophilic reaction of primary amines with 5-chloro- 2,3-diphenyltetrazolium salt via mesoionic 2,3-diphenyltetrazolium- 5-aminides

• Shuki Araki,
• Satoshi Hirose,
• Yoshikazu Konishi,
• Masatoshi Nogura and
• Tsunehisa Hirashita

Beilstein J. Org. Chem. 2009, 5, No. 8, doi:10.3762/bjoc.5.8

• amines have been examined. In the presence of an inorganic base such as NaHCO3, primary and secondary amines undergo a nucleophilic substitution to give the corresponding 5-aminotetrazolium salts. When triethylamine is used as a base, primary amines give 3-phenylazo-1,2,4-triazoles. A plausible dual-path

• hydrogencarbonate, 4a was obtained exclusively (Scheme 1). The results with other amines are summarized in Table 1. The reaction of butylamine showed a similar tendency: with the triethylamine base triazole 3b was obtained, whereas with sodium hydrogencarbonate 5-aminotetrazolium 4b was formed. Other primary amines

• , such as ethanolamine and ethyl glycinate gave the corresponding triazoles 3c and 3d. Interestingly, sterically bulky primary amines as well as secondary amines gave the respective 5-aminotetrazolium salts 4d–h. It is worthy to note that the reaction of isopropylamine/triethylamine gave 3

One-pot preparation of substituted pyrroles from α-diazocarbonyl compounds

• Fernando de C. da Silva,
• Mauricio G. Fonseca,
• Renata de S. Rianelli,
• Anna C. Cunha,
• Maria C. B. V. de Souza and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2008, 4, No. 45, doi:10.3762/bjoc.4.45

• -carbaldehyde (6) followed by reaction with primary amines. Keywords: diazocarbonyl; dihydrofuran; one-pot synthesis; pyrrole; Introduction The pyrrole unit [1] occurs in many interesting classes of compounds such as pharmaceutical agents [2][3][4][5], conducting polymers [6][7], molecular optics [8][9][10

• hexane-2,5-dione and primary amines under microwave irradiation. Other processes including several clay-mediated synthetic variations of these classical methods also have been reported for preparing pyrroles in equal or better yields [21]. In 2001 [22] and 2004 [23], Banik and co-workers, by using the

• variations in the reaction times (see Table 1). The reaction of the dihydrofuran intermediates 4, 5 and 6 with excess of primary amines in the presence of glacial acetic acid afforded the corresponding substituted pyrroles 7a–n in moderate to good yields (Table 1). Slightly different reactivity between 4, 5

The role of an aromatic group in remote chiral induction during conjugate addition of α-sulfonylallylic carbanions to ethyl crotonate

• Shlomo Levinger,
• Ranjeet Nair and
• Alfred Hassner

Beilstein J. Org. Chem. 2008, 4, No. 32, doi:10.3762/bjoc.4.32

• series of α-sulfonylallylic donor precursors 1, bearing a remote stereogenic center, were prepared by condensing a chiral aryl- or heteroarylalkylamine 6 with the bromo-substituted allyl sulfone 5 [2] (Scheme 2 and Table 1). Of the primary amines 6 used for generation of amino-substituted sulfones 1, 1

• -carbonitrile was indicated by formation of a 10-tert-butyl derivative on reaction with tert-butylmagnesium chloride [9]. However, since iminium ion intermediates are much more reactive than ketones [7], imines 8h and 8j were successfully reduced to the primary amines 6 upon treatment with sodium