Development of a method for the synthesis of 2,4,5-trisubstituted oxazoles composed of carboxylic acid, amino acid, and boronic acid

• Kohei Yamada,
• Naoto Kamimura and
• Munetaka Kunishima

Beilstein J. Org. Chem. 2017, 13, 1478–1485, doi:10.3762/bjoc.13.146

• 2,4,5-trisubstituted oxazoles in good yields. Keywords: one-pot oxazole synthesis; Suzuki–Miyaura coupling; triazine; 5-(triazinyloxy)oxazole; trisubstituted oxazole; Introduction Oxazoles are found in numerous natural products and are used as a broad range of artificial compounds [1][2]. In

Strategies toward protecting group-free glycosylation through selective activation of the anomeric center

• A. Michael Downey and
• Michal Hocek

Beilstein J. Org. Chem. 2017, 13, 1239–1279, doi:10.3762/bjoc.13.123

• the reaction with the corresponding triazine chloride and N-methylmorpholine. These agents are then able to selectively react with the anomeric center of a fully unprotected saccharide in the presence of an amine base in a dehydrative manner analogous to DMC from the previous section. These triazine

• donors are then isolated and reacted in the following step. The power of these two-step strategies is the ability to obtain the much more challenging 1,2-cis glycoside. In their first study [90] DBT-MM was generated in situ and reacted with three saccharides to form the triazine donor in good yield and

A novel method for heterocyclic amide–thioamide transformations

• Walid Fathalla,
• Ibrahim A. I. Ali and
• Pavel Pazdera

Beilstein J. Org. Chem. 2017, 13, 174–181, doi:10.3762/bjoc.13.20

• extra proton to II to afford the quinazoline thione C2. On the other hand the free cyclohexylamine will add to cyclohexyl isothiocyanate (4) to form the thiourea 3. Similar results were obtained by Furumoto [40], and Sun [41] reported the application of cyanuric chloride (2,4,6-trichloro-1,3,5-triazine

Elongated and substituted triazine-based tricarboxylic acid linkers for MOFs

• Arne Klinkebiel,
• Ole Beyer,
• Barbara Malawko and
• Ulrich Lüning

Beilstein J. Org. Chem. 2016, 12, 2267–2273, doi:10.3762/bjoc.12.219

• Arne Klinkebiel Ole Beyer Barbara Malawko Ulrich Luning Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität zu Kiel, Olshausenstr. 40, D-24098 Kiel, Germany 10.3762/bjoc.12.219 Abstract New triazine-based tricarboxylic acid linkers were prepared as elongated relatives of

• triazinetribenzoic acid (TATB). Additionally, functional groups (NO2, NH2, OMe, OH) were introduced for potential post-synthetic modification (PSM) of MOFs. Functionalized tris(4-bromoaryl)triazine “cores” (3a,3b) were obtained by unsymmetric trimerization mixing one equivalent of an acid chloride (OMe or NO2

• the methoxy group gave the respective amino and hydroxy-substituted triazine linkers. Keywords: isoreticular; linker; MOF; Suzuki coupling; triazine; Introduction A typical building block for many metal–organic frameworks (MOFs) [1][2][3][4] carries two functional groups such as carboxylic acids or

An effective one-pot access to polynuclear dispiroheterocyclic structures comprising pyrrolidinyloxindole and imidazothiazolotriazine moieties via a 1,3-dipolar cycloaddition strategy

• Alexei N. Izmest’ev,
• Galina A. Gazieva,
• Natalya V. Sigay,
• Sergei A. Serkov,
• Valentina A. Karnoukhova,
• Vadim V. Kachala,
• Alexander S. Shashkov,
• Igor E. Zanin,
• Angelina N. Kravchenko and
• Nina N. Makhova

Beilstein J. Org. Chem. 2016, 12, 2240–2249, doi:10.3762/bjoc.12.216

• regio- and diastereoselective one-pot method for the synthesis of new polynuclear dispiroheterocyclic systems with five stereogenic centers (dispiro[imidazo[4,5-e]thiazolo[3,2-b]-1,2,4-triazine-6,3′-pyrrolidine-2′,3′′-indoles]) comprising pyrrolidinyloxindole and imidazo[4,5-e]thiazolo[3,2-b]-1,2,4

• -triazine moieties has been developed. The method relies on a 1,3-dipolar cycloaddition of azomethine ylides generated in situ from isatin derivatives and sarcosine to 6-benzylideneimidazo[4,5-e]thiazolo[3,2-b]-1,2,4-triazine-2,7-diones. Keywords: azomethine ylides; cycloaddition; diastereoselectivity

• of many natural and synthetic bioactive products [33][34][35][36][37][38][39][40]. The pyrimido[5,4-e]-1,2,4-triazine constitutes the core of the antibiotics fervenulin, xanthothricin, and reumycin [33][34]. Other hetero-annelated 1,2,4-triazines reveal antiviral effect against influenza A and B

Hydroxy-functionalized hyper-cross-linked ultra-microporous organic polymers for selective CO₂ capture at room temperature

• Partha Samanta,
• Priyanshu Chandra and
• Sujit K. Ghosh

Beilstein J. Org. Chem. 2016, 12, 1981–1986, doi:10.3762/bjoc.12.185

• types of microporous organic materials including covalent organic frameworks (COFs), conjugate microporous polymers (CMPs), porous polymeric networks (PPNs), porous aromatic frameworks (PAFs), covalent triazine framework (CTFs), etc. [19][20][21][22][23][24]. Hyper-cross-linked microporous organic

Potent triazine-based dehydrocondensing reagents substituted by an amido group

• Munetaka Kunishima,
• Daiki Kato,
• Nobu Kimura,
• Masanori Kitamura,
• Kohei Yamada and
• Kazuhito Hioki

Beilstein J. Org. Chem. 2016, 12, 1897–1903, doi:10.3762/bjoc.12.179

• University, 1-1-3 Minatojima Chuo-ku, Kobe 655-8586, Japan 10.3762/bjoc.12.179 Abstract This study describes the synthesis of triazine-based dehydrocondensing reagents substituted by amido substituents and demonstrates their efficiency for dehydrocondensing reactions in MeOH and THF. N-Phenylbenzamido

• feature enables the use of DMT-MM for dehydrocondensing reactions in water or alcohols to give amides without the recovery of hydrolyzed carboxylic acids and the formation of corresponding esters. DMT-MM is quantitatively synthesized from 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT) and N-methylmorpholine

• intermediate in Scheme 1b, basically shows the same reactivity for aminolysis and alcoholysis regardless of which tertiary amine 5 was used (Scheme 1b,d). Therefore, it is reasonable to modify the activity of the 1,3,5-triazine ring that is involved in both steps shown in Scheme 1b by introducing another

New synthetic strategies for xanthene-dye-appended cyclodextrins

• Milo Malanga,
• Andras Darcsi,
• Mihaly Balint,
• Gabor Benkovics,
• Tamas Sohajda and
• Szabolcs Beni

Beilstein J. Org. Chem. 2016, 12, 537–548, doi:10.3762/bjoc.12.53

• formation of these byproducts could lead to depletion of the coupling agent by conversion to 2-hydroxy-4,6-dimethoxy-1,3,5-triazine (DMM-OH) and could explaining the moderate conversion of the starting material. It is worth emphasizing that the coupling of fluorescein based on DCC/HOBt in organic solvents

A journey in bioinspired supramolecular chemistry: from molecular tweezers to small molecules that target myotonic dystrophy

• Steven C. Zimmerman

Beilstein J. Org. Chem. 2016, 12, 125–138, doi:10.3762/bjoc.12.14

• use of a melamine (2,4,6-triamino-1,3,5-triazine) unit for formation of a base-triplet, as shown in Figure 8b. Additional reports by Lehn [78] and McLaughlin [79] supported this approach and the melamine unit has more recently been used extensively by Bong [80]. So why did we once again become

• bonds, hypothetically forming base-triplet with 2,4,6-triamino-1,3,5-triazine. (c) Aromatic recognition unit tethered to intercalator in stacked and unstacked conformation. (d) Ligand 27, an inhibitor of MBNL1N sequestration. (a) CTG trinucleotide repeat expansion in DMPK gene produces expanded

The simple production of nonsymmetric quaterpyridines through Kröhnke pyridine synthesis

• Isabelle Sasaki,
• Jean-Claude Daran and
• Gérard Commenges

Beilstein J. Org. Chem. 2015, 11, 1781–1785, doi:10.3762/bjoc.11.193

• pathway [17][20], or a Suzuki–Miyaura cross-coupling reaction [21]. The use of triazine derivatives (which under particular conditions undergo an inverse Diels–Alder reaction) can also produce oligopyridines [22]. On the other hand, there are a limited number of reports dealing with the preparation of

• nonsymmetric quaterpyridines; Constable et al. proposed a multistep synthesis of 4’-(alkylthio)quaterpyridines [23] to avoid the Stille palladium-catalyzed coupling, whereas Fallahpour obtained the 4’-nitroquaterpyridine by employing the Stille coupling method [24]. Sauer et al. extended the use of triazine

Photo, thermal and chemical degradation of riboflavin

• Muhammad Ali Sheraz,
• Sadia Hafeez Kazi,
• Sofia Ahmed,
• Zubair Anwar and
• Iqbal Ahmad

Beilstein J. Org. Chem. 2014, 10, 1999–2012, doi:10.3762/bjoc.10.208

• ,N-dioctadecyl-[1,3,5]triazine-2,4,6-triamine [122], certain amino acids and indole [123][124], proteins [125] and metals such as Ag+, Ru2+ [126] to enhance the photostability of the vitamin. Quenchers: RF on the absorption of light is promoted to the excited singlet state and then to the excited

Expeditive synthesis of trithiotriazine-cored glycoclusters and inhibition of Pseudomonas aeruginosa biofilm formation

• Meriem Smadhi,
• Sophie de Bentzmann,
• Anne Imberty,
• Marc Gingras,
• Raoudha Abderrahim and
• Peter G. Goekjian

Beilstein J. Org. Chem. 2014, 10, 1981–1990, doi:10.3762/bjoc.10.206

• glycoclusters based on a triazine core bearing D-galactose and L-fucose epitopes are able to inhibit biofilm formation by Pseudomonas aeruginosa. These multivalent ligands are simple to synthesize, are highly soluble, and can be either homofunctional or heterofunctional. The galactose-decorated cluster shows

• . Synthesis of ligands The glycoclusters were prepared from the inexpensive trithiocyanuric acid (1,3-5-triazine-2,4,6-trithiol) as the heteroaromatic core (Scheme 1). Trisubstitution of the commercial trisodium salt with propargyl bromide ensured the facile preparation of 2,4,6-tris(propargylthio)-1,3,5

• -triazine (2) as a key precursor [37]. The glycosyl units were incorporated via Cu(I)-catalyzed Huisgen cycloaddition with protected or unprotected glycosyl azides. We first investigated the Cu-catalyzed azide–alkyne cycloaddition (CuAAC) of acetyl protected β-D-galactopyranosyl azide 3 [38], to tris

Investigations of thiol-modified phenol derivatives for the use in thiol–ene photopolymerizations

• Sebastian Reinelt,
• Monir Tabatabai,
• Urs Karl Fischer,
• Norbert Moszner,
• Andreas Utterodt and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 1733–1740, doi:10.3762/bjoc.10.180

• suitable allyl-modified precursors and subsequent hydrolysis. Compared to PETMP better flexural strength and modulus of elasticity are achievable in thiol–ene photopolymerizations employing 1,3,5-triallyl-1,3,5-triazine-2,4,6-trione (TATATO) as the ene derivative. Especially, after storage in water, the

• photopolymerizations regarding the conversion and mechanical properties before and after water storage is investigated and compared to the widely used PETMP. Thereby, the well-established, commercially available triallyl-1,3,5-triazine-2,4,6-trione (TATATO) is utilized as the ene monomer. Results and Discussion

Multicomponent reactions in nucleoside chemistry

• Mariola Koszytkowska-Stawińska and
• Włodzimierz Buchowicz

Beilstein J. Org. Chem. 2014, 10, 1706–1732, doi:10.3762/bjoc.10.179

• nucleoside analogs were also prepared by these methods [101][102]. Sharma et al. used 2,4,6-trichloro[1,3,5]triazine (TCT) as the source of hydrogen chloride to promote the reactions leading to C-4-substituted C-nucleosides 81 with the high (ca. 7:1) diastereoisomeric ratio (Scheme 30) [103]. The products

Tailoring of organic dyes with oxidoreductive compounds to obtain photocyclic radical generator systems exhibiting photocatalytic behavior

• Christian Ley,
• Julien Christmann,
• Ahmad Ibrahim,
• Luciano H. Di Stefano and
• Xavier Allonas

Beilstein J. Org. Chem. 2014, 10, 936–947, doi:10.3762/bjoc.10.92

• , an electron acceptor and an electron donor leading to energy conversion through electron transfer, was the basis of the so called three-component systems. In this paper, an experimental work combining Rose bengal dye with a triazine derivative as electron acceptor and ethyl 4-(dimethylamino)benzoate

• ]. Hydrogen donor coinitiators could be amines [33][34][35][36][37][38], ethers [39][40], sulfides [41][42][43] or thiols [43][44][45]. Electron transfer coinitiators could be borate salts [46][47], iodonium [48][49] or triazine [32] derivatives. However, if Type II PIS gain sensitivity in the visible part of

• on the Rose Bengal as dye, and a triazine derivative (TA) as an acceptor (coinitiator). In addition, an amine (ethyl 4-(dimethylamino)benzoate, EDB) was chosen as redox (electron donor) additive for the PCIS (see Scheme 1). Type II photoinitiating system In Scheme 2, the typical reaction mechanism of

Metal and metal-free photocatalysts: mechanistic approach and application as photoinitiators of photopolymerization

• Jacques Lalevée,
• Sofia Telitel,
• Pu Xiao,
• Marc Lepeltier,
• Frédéric Dumur,
• Fabrice Morlet-Savary,
• Didier Gigmes and
• Jean-Pierre Fouassier

Beilstein J. Org. Chem. 2014, 10, 863–876, doi:10.3762/bjoc.10.83

• reactions. Reaction mechanisms for the Ru(ligand)32+/MDEA/R-Br system upon visible lights. Reaction mechanisms for the Violanthrone/Ru(ligand)32+/Ph2I+/R3SiH system upon visible lights. Reaction mechanisms for the MK/amine/triazine system upon visible lights.

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

Synthesis of 3,4-dihydro-1,8-naphthyridin-2(1H)-ones via microwave-activated inverse electron-demand Diels–Alder reactions

• Salah Fadel,
• Youssef Hajbi,
• Mostafa Khouili,
• Said Lazar,
• Franck Suzenet and
• Gérald Guillaumet

Beilstein J. Org. Chem. 2014, 10, 282–286, doi:10.3762/bjoc.10.24

• reaction to yield 5-aryl-3,4-dihydro-1,8-naphthyridin-2(1H)-ones by an efficient synthetic route. Keywords: inverse-electron-demand Diels–Alder reaction; microwave irradiation; naphthyridin-2(1H)-ones; Sonogashira cross-coupling; 1,2,4-triazine; Introduction 1,8-Naphthyridine derivatives are an important

• . Results and Discussion Synthesis of 1,7-disubstituted 3,4-dihydro-1,8-naphthyridin-2(1H)-ones 3-Methylsulfonyl-5-phenyl-1,2,4-triazine Our strategy was first based on the 3-methylsulfonyl-1,2,4-triazine 1 (Scheme 1). This key triazine 1 was prepared according to the procedure described by Taylor and

• synthesis of 1-substituted 3,4-dihydro-1,8-naphthyridin-2(1H)-ones by using 1,2,4-triazine and alkyne tethered together by an amide linker. Synthesis of 1,5,7-trisubstituted-3,4-dihydro-1,8-naphthyridin-2(1H)-ones In order to functionalize the 4-position of the pyridine ring and to extend diversity, we

An overview of the synthetic routes to the best selling drugs containing 6-membered heterocycles

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2013, 9, 2265–2319, doi:10.3762/bjoc.9.265

• carmegliptin as its HCl salt. 3. Pyrimidines and quinazolines Whilst pyridine rings and their partially or fully saturated derivatives are very frequent components of pharmaceutical species there are also a considerable number of compounds based on diazine and triazine ring systems. Amongst the diazines

Metal-free aerobic oxidations mediated by N-hydroxyphthalimide. A concise review

• Lucio Melone and
• Carlo Punta

Beilstein J. Org. Chem. 2013, 9, 1296–1310, doi:10.3762/bjoc.9.146

• the photocatalytic oxidative activation of NHPI by graphitic carbon nitride (g-C3N4) and visible light irradiation [65]. g-C3N4, the most stable allotrope of carbon nitride, is a two-dimensional polymer with a tri-s-triazine ring unit and a π-conjugated layered structure similar to graphene. It is a

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

• Pictet–Spengler reaction catalyzed by cyanuric chloride (trichloro-1,3,5-triazine, TCT) is described. The 6-endo cyclization of tryptophan/tryptamine and modified Pictet–Spengler substrates with both electron-withdrawing and electron-donating aldehydes was carried out by using a catalytic amount of TCT

• additional deprotection step has to be introduced. Instead, a mild and efficient catalyst that can effectively produce iminium species in situ could generate the compound of interest without adding any extra steps. We envisaged that the use of cyanuric chloride (2,4,6-trichloro-1,3,5-triazine, TCT) [38][39

New core-pyrene π structure organophotocatalysts usable as highly efficient photoinitiators

• Sofia Telitel,
• Frédéric Dumur,
• Thomas Faury,
• Bernadette Graff,
• Mohamad-Ali Tehfe,
• Didier Gigmes,
• Jean-Pierre Fouassier and
• Jacques Lalevée

Beilstein J. Org. Chem. 2013, 9, 877–890, doi:10.3762/bjoc.9.101

• architectures (Scheme 2) [42][43][44] are linked PI–PI units (e.g., PI = pyrene) or PI-PI’ (e.g., PI = pyrene and PI’ = 2,2’-dimethoxy-2-phenylacetophenone) and PI moieties (e.g., PI = benzophenone, thioxanthone, 2,2’-dimethoxy-2-phenylacetophenone, pyrene) linked to a trifunctional core (truxene, triazine

Spin state switching in iron coordination compounds

• Philipp Gütlich,
• Ana B. Gaspar and
• Yann Garcia

Beilstein J. Org. Chem. 2013, 9, 342–391, doi:10.3762/bjoc.9.39

Bioactive selaginellins from Selaginella tamariscina (Beauv.) Spring

• Chao Yang,
• Yutian Shao,
• Kang Li and
• Wujiong Xia

Beilstein J. Org. Chem. 2012, 8, 1884–1889, doi:10.3762/bjoc.8.217

• conducted on precoated silica gel plates GF254 (Qingdao Marine Chemical Factory). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), cisplatin, and 2,4,6-tri(2-pyridyl)-1,3,5-triazine (TPTZ) were from Aladdin Reagent Co. Ltd. 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium

Regioselective synthesis of 7,8-dihydroimidazo[5,1-c][1,2,4]triazine-3,6(2H,4H)-dione derivatives: A new drug-like heterocyclic scaffold

• Nikolay T. Tzvetkov,
• Harald Euler and
• Christa E. Müller

Beilstein J. Org. Chem. 2012, 8, 1584–1593, doi:10.3762/bjoc.8.181

• /bjoc.8.181 Abstract Dihydroimidazo[5,1-c][1,2,4]triazine-3,6(2H,4H)-dione derivatives were prepared by successive N3- and N1-alkylation of hydantoins, followed by regioselective thionation and subsequent cyclization under mild conditions. In a final alkylation step a further substituent may be

• ] properties. The impressive array of biological effects of these compounds is associated with the 1,2,4-triazine ring as the core structural moiety, which also occurs in a number of natural products [5]. In addition, the 1,2,4-triazine scaffold has found application in pharmaceuticals and agrochemicals [6

• ]. For example, some 7-phenylimidazo-[1,2.b][1,2,4]triazine derivatives of the general structure 1 (Figure 1) have been developed as selective ligands for γ-aminobutyric acid type A (GABAA) receptors and are therefore of benefit in the treatment and prevention of adverse conditions of the central nervous