Recent advances in transition-metal-catalyzed incorporation of fluorine-containing groups

• Xiaowei Li,
• Xiaolin Shi,
• Xiangqian Li and
• Dayong Shi

Beilstein J. Org. Chem. 2019, 15, 2213–2270, doi:10.3762/bjoc.15.218

Tautomerism as primary signaling mechanism in metal sensing: the case of amide group

• Vera Deneva,
• Georgi Dobrikov,
• Aurelien Crochet,
• Daniela Nedeltcheva,
• Katharina M. Fromm and
• Liudmil Antonov

Beilstein J. Org. Chem. 2019, 15, 1898–1906, doi:10.3762/bjoc.15.185

• solution: Aniline (0.90 mL, 10.00 mmol) was dissolved in a mixture of concentrated hydrochloric acid (5 mL) and distilled water (20 mL). A solution of sodium nitrite (0.83 g, 12.00 mmol) in distilled water (5 mL) was prepared in a test tube. The sodium nitrite solution was added dropwise to the acidic

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

• the past few years [57]. Recently, Buchwald and Castillo have reviewed the exceptional utility of Pd-catalyzed C–N cross-coupling reactions for the preparation of anilines and aniline derivatives [58]. In many of the reactions, palladium was used along with a co-catalyst to enhance its catalytic

Enantioselective PCCP Brønsted acid-catalyzed aza-Piancatelli rearrangement

• Gabrielle R. Hammersley,
• Meghan F. Nichol,
• Helena C. Steffens,
• Jose M. Delgado,
• Gesine K. Veits and
• Javier Read de Alaniz

Beilstein J. Org. Chem. 2019, 15, 1569–1574, doi:10.3762/bjoc.15.160

• -, meta-, and para-substituted aniline derivatives. The reaction of anilines bearing an electron-withdrawing group at the para-position afforded the optimal balance between efficiency and enantioselectivity. Consistent with Rueping’s work [35], ortho-aminobenzoic acid, which contains an additional

• bonding capability of the carboxylic acid group. In contrast, with the exception of 7p and 7q, a lower yield was obtained when ortho-aminobenzoic acid was used. Presumably, this decrease in efficiency is due to the increased steric bulk on the aniline, which slows the initial nucleophilic attack on the

• acid catalyzed reaction shows good substrate scope and proceeds well with a range of aniline and furylcarbinol derivatives. The ability to control the absolute stereochemistry of the 4π electrocylization using an inexpensive and easy to prepare chiral Brønsted acid catalyst holds tremendous promise for

Formation of an unexpected 3,3-diphenyl-3H-indazole through a facile intramolecular [2 + 3] cycloaddition of the diazo intermediate

• Andrew T. King,
• Hugh G. Hiscocks,
• Lidia Matesic,
• Mohan Bhadbhade,
• Roger Bishop and
• Alison T. Ung

Beilstein J. Org. Chem. 2019, 15, 1347–1354, doi:10.3762/bjoc.15.134

• ]. More recently, the formation of cyclic 3,3-disubstituted 3H-indazoles was reported to form mainly through the [2 + 3] cycloaddition of diazo compounds with arynes under mild reaction conditions [29][30][31]. However, none of these contained a 2-diphenylmethyl (benzhydryl) aniline system, as found in

Doebner-type pyrazolopyridine carboxylic acids in an Ugi four-component reaction

• Maryna V. Murlykina,
• Oleksandr V. Kolomiets,
• Maryna M. Kornet,
• Yana I. Sakhno,
• Sergey M. Desenko,
• Victoriya V. Dyakonenko,
• Svetlana V. Shishkina,
• Oleksandr A. Brazhko,
• Vladimir I. Musatov,
• Alexander V. Tsygankov,
• Erik V. Van der Eycken and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2019, 15, 1281–1288, doi:10.3762/bjoc.15.126

• optimal acidity to the reaction medium needed for successful protonation of the intermediate azomethine, formed between the aromatic aldehyde 8 and aniline 9, to the corresponding iminium cation and its further transformation involving carboxylic acid 4 and isocyanide 10. As a result, we developed an

Steroid diversification by multicomponent reactions

• Leslie Reguera,
• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Daniel G. Rivera

Beilstein J. Org. Chem. 2019, 15, 1236–1256, doi:10.3762/bjoc.15.121

• ]. In short, the organocatalytic conjugated addition of benzoylacetonitrile to cinnamaldehyde generates the hemiacetal 30, which next initiates the multicomponent sequence upon condensation with the aniline and formation of the imine, eventually occurring as a stable cyclic aminal. The attack of the

Electrophilic oligodeoxynucleotide synthesis using dM-Dmoc for amino protection

• Shahien Shahsavari,
• Dhananjani N. A. M. Eriyagama,
• Bhaskar Halami,
• Vagarshak Begoyan,
• Marina Tanasova,
• Jinsen Chen and
• Shiyue Fang

Beilstein J. Org. Chem. 2019, 15, 1116–1128, doi:10.3762/bjoc.15.108

• electrophilic oligodeoxynucleotides (ODNs) was achieved using dimethyl-Dmoc (dM-Dmoc) as amino protecting group. Due to the high steric hindrance of the 2-(propan-2-ylidene)-1,3-dithiane side product from deprotection, the use of excess nucleophilic scavengers such as aniline to prevent Michael addition of the

• , we found that the deprotection and cleavage could be achieved by oxidation with sodium periodate followed by treating with the mild base aniline at room temperature. Due to the mild deprotection and cleavage conditions, we concluded that the technology was suitable for the synthesis of sensitive ODNs

• that contain electrophilic groups. However, at the current state of art one drawback of the technology is that large excess aniline has to be used as a scavenger to prevent the deprotection side product 1 from reacting with the deprotected ODNs via Michael addition. Aniline is a weak nucleophile, but

Mechanochemistry of supramolecules

• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2019, 15, 881–900, doi:10.3762/bjoc.15.86

• organocatalysis using PhI (10 mol %)–mCPBA at ambient conditions as well as under neat mixing [115]. The N1,N1-dibenzylbenzene-1,2-diamine (Figure 27) which is an integrated system by the combination of aniline and N,N-dibenzylaniline led to the successful formation of 1-benzyl-2-phenyl-benzo[d]imidazole 48 under

Synthesis of a novel category of pseudo-peptides using an Ugi three-component reaction of levulinic acid as bifunctional substrate, amines, and amino acid-based isocyanides

• Maryam Khalesi,
• Azim Ziyaei Halimehjani and
• Jürgen Martens

Beilstein J. Org. Chem. 2019, 15, 852–857, doi:10.3762/bjoc.15.82

• -peptides. For this purpose, aliphatic amines such as o-chlorobenzylamine and tryptamine and aromatic amines such as aniline, 4-chloroaniline, 4-aminophenol, p-toluidine, 4-fluoroaniline, and m-anisidine were applied successfully in this protocol. In addition, all three prepared isocyanides from DL

Microwave-assisted synthesis of N,N-bis(phosphinoylmethyl)amines and N,N,N-tris(phosphinoylmethyl)amines bearing different substituents on the phosphorus atoms

• Erika Bálint,
• Anna Tripolszky,
• László Hegedűs and
• György Keglevich

Beilstein J. Org. Chem. 2019, 15, 469–473, doi:10.3762/bjoc.15.40

• ) and a secondary phosphine oxide react in a condensation reaction [1]. However, only a few papers deal with the synthesis of α-aminophosphine oxides. (Phenylaminomethyl)dibenzylphosphine oxide was prepared by the three-component reaction of aniline, paraformaldehyde and dibenzylphosphine oxide [7], as

• well as by the reaction of (hydroxymethyl)dibenzylphosphine oxide and aniline [8]. The condensation of butylamine, paraformaldehyde and di(p-tolyl)phosphine oxide to afford (butylaminomethyl)di(p-tolyl)phosphine oxide was also described [9]. A microwave (MW)-assisted, catalyst-free method was

Adhesion, forces and the stability of interfaces

• Robin Guttmann,
• Johannes Hoja,
• Christoph Lechner,
• Reinhard J. Maurer and
• Alexander F. Sax

Beilstein J. Org. Chem. 2019, 15, 106–129, doi:10.3762/bjoc.15.12

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

• multicomponent Mannich-type synthesis of β-aminocarbonyl products 16 in suitable times and yields (Scheme 2). To check the reusability of the catalysts, the reaction between benzaldehyde, aniline, and acetophenone in 5 mmol scale in ethanol was chosen. All catalysts were recycled three times using filtration of

• protected aniline derivatives were obtained by the solvent-free reaction of anilines with 1,3-diketones at 120 °C or 140 °C in the presence of 2 equiv of water under 1 atm O2 atmosphere (Scheme 16). The probable reaction pathway for this reaction is shown in Scheme 16. Arylamine 15 attacks the activated

Gold-catalyzed post-Ugi alkyne hydroarylation for the synthesis of 2-quinolones

• Xiaochen Du,
• Jianjun Huang,
• Anton A. Nechaev,
• Ruwei Yao,
• Jing Gong,
• Erik V. Van der Eycken,
• Olga P. Pereshivko and
• Vsevolod A. Peshkov

Beilstein J. Org. Chem. 2018, 14, 2572–2579, doi:10.3762/bjoc.14.234

• functionalization [25][26][27][28][29] of the 2-quinolone scaffold has become a budding research trend. In the last decade, a great number of efficient approaches has been developed utilizing transition metal-catalyzed [30][31][32], Lewis acid-mediated [33], and radical cyclizations [34] of various aniline

Quinolines from the cyclocondensation of isatoic anhydride with ethyl acetoacetate: preparation of ethyl 4-hydroxy-2-methylquinoline-3-carboxylate and derivatives

• Nicholas G. Jentsch,
• Jared D. Hume,
• Emily B. Crull,
• Samer M. Beauti,
• Amy H. Pham,
• Julie A. Pigza,
• Jacques J. Kessl and
• Matthew G. Donahue

Beilstein J. Org. Chem. 2018, 14, 2529–2536, doi:10.3762/bjoc.14.229

• regioselectivity issues and practical challenges associated with the aniline cyclocondensation (7→8), along with the scarcity of commercially available highly substituted quinolines, we sought to employ an entirely different tactic by utilizing 2H-3,1-benzoxazine-2,4(1H)-dione (isatoic anhydride) chemistry [16][17

• ester carbonyl of the isatoic anhydride forming tetrahedral intermediate A. Subsequent collapse of the sp3-hybridized carbon to the ketone B with concomitant expulsion of carbon dioxide and enolization affords the ketone C. The anion of the aniline nitrogen then attacks the ketone carbonyl via

Synthesis of aryl sulfides via radical–radical cross coupling of electron-rich arenes using visible light photoredox catalysis

• Amrita Das,
• Mitasree Maity,
• Simon Malcherek,
• Burkhard König and
• Julia Rehbein

Beilstein J. Org. Chem. 2018, 14, 2520–2528, doi:10.3762/bjoc.14.228

• of the reaction mixture, also when nitrobenzene (PhNO2) was used as oxidant, trace amounts of product were observed along with the formation of aniline, likely arising from the regeneration of the catalyst. Control experiments confirmed that light and photocatalyst were essential for the arylation

Synthesis of dihydroquinazolines from 2-aminobenzylamine: N³-aryl derivatives with electron-withdrawing groups

• Nadia Gruber,
• Jimena E. Díaz and
• Liliana R. Orelli

Beilstein J. Org. Chem. 2018, 14, 2510–2519, doi:10.3762/bjoc.14.227

• ][43][44] or formic [45] acid to yield symmetrically substituted 3,4-DHQs, usually in low yields [45] and accompanied by several by-products [46][47]. In addition, this strategy is limited to the preparation of 3,6-disubstituted compounds, because a p-substituted aniline is required to block this

Synthesis of indolo[1,2-c]quinazolines from 2-alkynylaniline derivatives through Pd-catalyzed indole formation/cyclization with N,N-dimethylformamide dimethyl acetal

• Antonio Arcadi,
• Sandro Cacchi,
• Giancarlo Fabrizi,
• Francesca Ghirga,
• Antonella Goggiamani,
• Antonia Iazzetti and
• Fabio Marinelli

Beilstein J. Org. Chem. 2018, 14, 2411–2417, doi:10.3762/bjoc.14.218

• or by sequential Pd-catalyzed reaction of o-(o-aminophenylethynyl)aniline with DMFDMA. Keywords: arylboronic acids; DMFDMA; indoles; indoloquinazolines; quinazolines; Introduction Indoloquinazoline derivatives constitute an important class of compounds which exhibit a wide range of biological

• -arylindolo[1,2-c]quinazolines 10 from o-(o-aminophenylethynyl) trifluoroacetanilides 5 and arylboronic acids, by avoiding the isolation of intermediate indoles 9. Starting from indoles 14, or from o-(o-aminophenylethynyl)aniline 15a, selective formation of 12-unsubstituted[1,2-c]quinazolines 13 was

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

• benzaldehydes, aniline and IBX under ball-milling conditions an explosion was observed (Figure 1a; Caution! see experimental section) [30][31] and similar observations were made with Dess–Martin periodinane (DMP). On the other hand, benzamide was found to be unreactive with IBX and no reaction was observed

• aniline derivative with moderate reactivity. Therefore, we anticipate that the controlled reactivity of IBX under mechano-milling conditions led to successful reaction with 2-aminobenzamide. Finally, a large scale synthesis was performed to prove the synthetic utility of this methodology. By taking

• ). Melting points (mp) of the compounds were determined using a digital melting point apparatus and are uncorrected. Caution. When aniline and IBX are mixed under solvent-free conditions or at maximum contact, immediate explosion was observed. However, no explosion could be observed under similar conditions

Practical tetrafluoroethylene fragment installation through a coupling reaction of (1,1,2,2-tetrafluorobut-3-en-1-yl)zinc bromide with various electrophiles

• Ken Tamamoto,
• Shigeyuki Yamada and
• Tsutomu Konno

Beilstein J. Org. Chem. 2018, 14, 2375–2383, doi:10.3762/bjoc.14.213

• . 4n was smoothly converted to the corresponding aniline derivative 4s in 87% isolated yield, after exposure to a reductive environment using Fe powder and NH4Cl. Subsequent Sandmeyer reaction of 4s took place very nicely to afford the corresponding CF2CF2-substituted iodobenzene derivative 4t in 67

Revisiting ring-degenerate rearrangements of 1-substituted-4-imino-1,2,3-triazoles

• James T. Fletcher,
• Matthew D. Hanson,
• Joseph A. Christensen and
• Eric M. Villa

Beilstein J. Org. Chem. 2018, 14, 2098–2105, doi:10.3762/bjoc.14.184

• groups attached at the para-phenyl positions of both 1-phenyl-4-formyl-1,2,3-triazole and aniline reactants were used in the current investigation. Two reaction conditions were employed in this study. Low temperature conditions used a 1:1 CHCl3/MeOH solvent system at room temperature, identified as

• where an electron-rich triazole was paired with an electron-poor aniline generated significant populations of rearranged imine products (Table 2, entries 16, and 22–24). This stands as a cautionary observation informing the design of 1-substituted-4-imino-1,2,3-triazoles intended for exposure to high

Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry

• Michael K. Bogdos,
• Emmanuel Pinard and
• John A. Murphy

Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179

• electron-poor heterocycles under the current conditions. However, the aniline coupling partner opens up a huge variety of opportunities, as arylamines and heteroarylamines are widely available. Scaffolds such as 7b have lots of potential for further elaboration. In addition, the presence of electron-poor

Rational design of boron-dipyrromethene (BODIPY) reporter dyes for cucurbit[7]uril

• Mohammad A. Alnajjar,
• Jürgen Bartelmeß,
• Robert Hein,
• Pichandi Ashokkumar,
• Mohamed Nilam,
• Werner M. Nau,
• Knut Rurack and
• Andreas Hennig

Beilstein J. Org. Chem. 2018, 14, 1961–1971, doi:10.3762/bjoc.14.171

• -dipyrromethene (BODIPY) dyes as a new class of fluorophores for the design of reporter dyes for supramolecular host–guest complex formation with cucurbit[7]uril (CB7). The BODIPYs contain a protonatable aniline nitrogen in the meso-position of the BODIPY chromophore, which was functionalized with known binding

• motifs for CB7. The unprotonated dyes show low fluorescence due to photoinduced electron transfer (PET), whereas the protonated dyes are highly fluorescent. Encapsulation of the binding motif inside CB7 positions the aniline nitrogen at the carbonyl rim of CB7, which affects the pKa value, and leads to a

• (BODIPYs) with an aniline substituent in the meso-position as fluorescent dyes in this type of anchor approach (Figure 1). BODIPYs are a class of fluorescent dyes that are particularly suitable for applications in medical imaging, and as fluorescent labels in biology, biochemistry and related fields [29

A pyridinium/anilinium [2]catenane that operates as an acid–base driven optical switch

• Sarah J. Vella and
• Stephen J. Loeb

Beilstein J. Org. Chem. 2018, 14, 1908–1916, doi:10.3762/bjoc.14.165

• benzylanilinium, as well as a smaller DB24C8 ring was synthesized and characterized. 1H NMR spectroscopy showed that the DB24C8 ring can shuttle between the two recognition sites depending on the protonation state of the larger macrocycle. When the aniline group is neutral, the DB24C8 ring resides solely at the

• chemical shifts for protons a–d and I–L on the benzylaniline portion of the large ring of [8DB24C8]6+ do not shift significantly inferring that in the neutral aniline state the crown ether resides exclusively at the bis(pyridinium)ethane site of the [2]catenane. Table 1 summarizes the chemical shift

• protonation of the aniline nitrogen atom to give [8-HDB24C8]7+ and a second viable recognition site for the crown ether. Figure 4 shows a partial 1H NMR spectrum of protonated [8-HDB24C8]7+ in CD3CN at 298 K. The smaller DB24C8 ring can now reside at either of the bis(pyridinium)ethane or benzylanilinium

Design, synthesis and structure of novel G-2 melamine-based dendrimers incorporating 4-(n-octyloxy)aniline as a peripheral unit

• Cristina Morar,
• Pedro Lameiras,
• Attila Bende,
• Gabriel Katona,
• Emese Gál and
• Mircea Darabantu

Beilstein J. Org. Chem. 2018, 14, 1704–1722, doi:10.3762/bjoc.14.145

• Background: 4-(n-Octyloxy)aniline is a known component in the elaboration of organic materials with mesogenic properties such as N-substituted Schiff bases, perylene bisimide assemblies with a number of 2-amino-4,6-bis[4-(n-octyloxy)phenylamino]-s-triazines, amphiphilic azobenzene-containing linear-dendritic

• block copolymers and G-0 monomeric or dimeric dendritic liquid crystals with photochromic azobenzene mesogens. The present ab initio study explores a previously unknown use of 4-(n-octyloxy)aniline in the synthesis, structure and supramolecular behaviour of new dendritic melamines. Results: Starting

• from 4-(n-octyloxy)aniline, seven G-2 melamine-based dendrimers were obtained in 29–79% overall yields. Their iterative convergent- and chemoselective synthesis consisted of SN2-Ar aminations of cyanuric chloride and final triple N-acylations and Williamson etherifications (→ G-2 covalent trimers) or