Sequential Ugi reaction/base-induced ring closing/IAAC protocol toward triazolobenzodiazepine-fused diketopiperazines and hydantoins

• Robby Vroemans,
• Fante Bamba,
• Jonas Winters,
• Joice Thomas,
• Jeroen Jacobs,
• Luc Van Meervelt,
• Jubi John and
• Wim Dehaen

Beilstein J. Org. Chem. 2018, 14, 626–633, doi:10.3762/bjoc.14.49

• , we investigated the effect of the substitution pattern on the propargylamine 2. For this, we chose easily available propargylamines 2b and 2c which gave moderate to good yields (60 and 40%, respectively) of diketopiperazine-fused triazolobenzodiazepine 7e and 7f. Furthermore, halogen substituents

Recent advances on organic blue thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs)

• Thanh-Tuân Bui,
• Fabrice Goubard,
• Malika Ibrahim-Ouali,
• Didier Gigmes and
• Frédéric Dumur

Beilstein J. Org. Chem. 2018, 14, 282–308, doi:10.3762/bjoc.14.18

• substitution pattern of the carbazole unit on the photophysical properties. While maintaining the same number of carbazole units on the emitter and by varying the substitution pattern of the carbazole core, only a weak influence on the EL characteristics was evidenced [55]. In fact, performances only varied by

Photocatalytic formation of carbon–sulfur bonds

• Alexander Wimmer and
• Burkhard König

Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4

• sulfenylated dienes by dehydration. A series of aryl thiols with different steric and electronic properties give high yields of the thiol–yne products. Noteworthy is the high E-selectivity of the resulting alkene. Dependent on the substitution pattern of the aryl thiol a ratio up to 60:1 was observed due to

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation and chlorination. Part 2: Use of CF₃SO₂Cl

• Hélène Chachignon,
• Hélène Guyon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2800–2818, doi:10.3762/bjoc.13.273

• also suitable to carry out this reaction [12]. The same tendencies in term of reactivity of the substrates depending on their substitution pattern was observed, and similar yields were achieved (Scheme 10). Similarly, Ir(ppy)2(dtbbpy)PF6 was also described as an appropriate catalyst for this cascade

• selectively place from a direction anti to the CF3 group, probably because of electrostatic repulsion. The reaction proceeded smoothly with prop-1-yn-1-ylbenzene derivatives, indifferently to the substitution pattern of the aryl moiety. As for the R group, alkyl, ester or amide moieties were well-tolerated

Synthesis of 1,3-cis-disubstituted sterically encumbered imidazolidinone organocatalysts

• Jan Wallbaum and
• Daniel B. Werz

Beilstein J. Org. Chem. 2017, 13, 2577–2583, doi:10.3762/bjoc.13.254

• subtle differences in the substitution pattern a modular approach for their preparation is highly desirable. A simple retrosynthetic cut of the five-membered ring delivers an amino acid methyl amide and a carbaldehyde as starting materials. Chirality is commonly introduced by the use of derivatives of

Syntheses, structures, and stabilities of aliphatic and aromatic fluorous iodine(I) and iodine(III) compounds: the role of iodine Lewis basicity

• Tathagata Mukherjee,
• Soumik Biswas,
• Andreas Ehnbom,
• Subrata K. Ghosh,
• Ibrahim El-Zoghbi,
• Nattamai Bhuvanesh,
• Hassan S. Bazzi and
• John A. Gladysz

Beilstein J. Org. Chem. 2017, 13, 2486–2501, doi:10.3762/bjoc.13.246

• substitution pattern was evident from the 1H NMR spectrum. When Cl2 gas was sparged through a CF3C6H5 solution of 1,3,5-(Rf6)2C6H3I at −30 °C to −35 °C, the sample turned bright yellow. Two aliquots were removed. The 1H NMR spectrum of one (Figure 1b) showed two downfield shifted signals (cf. Figure 1a), which

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

• can be detected and monitored by absorption and emission spectroscopy. Furthermore, the investigation of a substance library of various 2,3- and 1,8-naphthalene imides has shown that the electronic nature of the ground and the excited state is decisively influenced by variation of the substitution

• pattern of the naphthalene scaffold. Even the smallest polarity change in the solvent system effects their absorption and emission behavior [34][40]. Very recent investigations on naphthaleneimide derivatives revealed enormous phosphorescence lifetimes that are particularly interesting for imaging

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

• - and Z-1b, and depending on the substitution pattern of the aziridine ring, the formation of the pyrrolidine derivative 34 occurred either with complete stereoselectivity or mixtures of isomeric products were obtained. The [3 + 2]-cycloaddition of the azomethine ylide E,Z-32a, formed via conrotatory

The chemistry and biology of mycolactones

• Matthias Gehringer and
• Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

Base-promoted isomerization of CF₃-containing allylic alcohols to the corresponding saturated ketones under metal-free conditions

• Yoko Hamada,
• Tomoko Kawasaki-Takasuka and
• Takashi Yamazaki

Beilstein J. Org. Chem. 2017, 13, 1507–1512, doi:10.3762/bjoc.13.149

• intermolecular reprotonation by the solvent. The present interesting proton shift reaction was also computationally simulated [7] by employing (R,E)-6h with the substitution pattern of R1 = Ph and R2 = Me as the model substrate. For simplicity, 1,4-diazabicyclo[2.2.2]octane (DABCO) was employed as the

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

• substitution pattern at the 4-position of the oxazole. The one-pot oxazole synthesis with phenylalanine (2b), valine (2c), leucine (2d), methionine (2e), and phenylglycine (2f) proceeded to give the corresponding intermediates in good yields (Table 1, entries 6–10). Despite the existence of highly polar

Photocatalyzed synthesis of isochromanones and isobenzofuranones under batch and flow conditions

• Manuel Anselmo,
• Lisa Moni,
• Hossny Ismail,
• Davide Comoretto,
• Renata Riva and
• Andrea Basso

Beilstein J. Org. Chem. 2017, 13, 1456–1462, doi:10.3762/bjoc.13.143

• isochromanone 4a in 72% yield (Scheme 2 and Table 1). Analogous results were obtained when the substitution pattern on both the diazonium salt and the alkene was varied, results that paralleled those reported by König and Fagnoni [5]. In our hands reactions were slower (6–8 h vs 2 h), probably due to the lower

A speedy route to sterically encumbered, benzene-fused derivatives of privileged, naturally occurring hexahydropyrrolo[1,2-b]isoquinoline

• Olga Bakulina,
• Alexander Ivanov,
• Vitalii Suslonov,
• Dmitry Dar’in and
• Mikhail Krasavin

Beilstein J. Org. Chem. 2017, 13, 1413–1424, doi:10.3762/bjoc.13.138

•  5). The tolerance of the reaction to the substitution pattern in the aromatic portion of the indolenines appears rather broad, both in terms of the electronic character of substituents and steric effects – although substituents in position 7 of the indolenine significantly affect the conformational

Synthesis of alkynyl-substituted camphor derivatives and their use in the preparation of paclitaxel-related compounds

• M. Fernanda N. N. Carvalho,
• Rudolf Herrmann and
• Gabriele Wagner

Beilstein J. Org. Chem. 2017, 13, 1230–1238, doi:10.3762/bjoc.13.122

• , leading to pure dialkynes with a well-defined substitution pattern. The reactivity of a pair of isomers containing a phenyl and a pentyl group attached to the triple bonds towards cycloisomerisation induced by Pt(II) catalysis was studied. The expected annulation–sulphur reduction–ring enlargement cascade

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

• the substitution pattern in the carbonyl component is related with the ability of the intermediate Schiff bases to be protonated as well as with their solubility. In case of the presence of electron-withdrawing substituents in the aldehyde the corresponding Schiff bases 5 are less soluble and less

A practical and efficient approach to imidazo[1,2-a]pyridine-fused isoquinolines through the post-GBB transformation strategy

• Taofeng Shao,
• Zhiming Gong,
• Tianyi Su,
• Wei Hao and
• Chao Che

Beilstein J. Org. Chem. 2017, 13, 817–824, doi:10.3762/bjoc.13.82

• , the substitution pattern of the amidine moiety had little effect on the Au-catalyzed annulation reaction, whereas neutral or electron-donating groups on the aldehyde moiety gave a higher yield in comparison with the electron-withdrawing halides. Notably, bromo-substituted substrates were also

Cyclodextrins tethered with oligolactides – green synthesis and structural assessment

• Cristian Peptu,
• Mihaela Balan-Porcarasu,
• Alena Šišková,
• Ľudovít Škultéty and
• Jaroslav Mosnáček

Beilstein J. Org. Chem. 2017, 13, 779–792, doi:10.3762/bjoc.13.77

• and small amounts of functionalized CD-LA and L-lactide monomer. All samples showed peaks for the unreacted L-lactide and separated peaks for the protons of the substituted glucopyranose units. In the 1H NMR spectra the substitution pattern of the glycoside rings of cyclodextrins can be followed by

Dimerization reactions of aryl selenophen-2-yl-substituted thiocarbonyl S-methanides as diradical processes: a computational study

• Michael L. McKee,
• Grzegorz Mlostoń,
• Katarzyna Urbaniak and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 410–416, doi:10.3762/bjoc.13.44

• convenient access comprises the treatment of a C=S substrate with diazomethane or its derivatives. Depending on the substitution pattern, 2,5-dihydro-1,3,4-thiadiazoles 2 display different thermal stability. Whereas sterically bulky aliphatic substituents increase the temperature required for the

Highly reactive, liquid diacrylamides via synergistic combination of spatially arranged curing moieties

• Maximilian Maier,
• Magnus S. Schmidt,
• Markus Ringwald and
• Christoph P. Fik

Beilstein J. Org. Chem. 2017, 13, 372–383, doi:10.3762/bjoc.13.40

• as relatively low viscous, highly soluble/compatible liquids [19]. Furthermore, acrylamides are generally more reactive than the respective methacrylamides. Regarding the substitution pattern, N-monosubstituted acrylamides tend to homopolymerize more readily than their N,N-disubstituted analogues [20

Construction of bis-, tris- and tetrahydrazones by addition of azoalkenes to amines and ammonia

• Artem N. Semakin,
• Aleksandr O. Kokuev,
• Yulia V. Nelyubina,
• Alexey Yu. Sukhorukov,
• Petr A. Zhmurov,
• Sema L. Ioffe and
• Vladimir A. Tartakovsky

Beilstein J. Org. Chem. 2016, 12, 2471–2477, doi:10.3762/bjoc.12.241

• ]. Tetraazaadamantane with this substitution pattern is a promising platform for the design of supramolecular recognizing systems and for the construction of new molecular cage architectures. The formation of the 1,4,6,10-tetraazaadamantane cage was unambiguously confirmed by X-ray analysis of the crystal solvate of

• isomers depends on the substitution pattern and solvent. For example, the E,E-isomer was predominant for 2a in DMSO-d6, while in CDCl3 E,Z-2a was the major isomer. The assignment of stereoisomers was performed using known correlations between the configuration of the C=N bond and the chemical shift of

A new paradigm for designing ring construction strategies for green organic synthesis: implications for the discovery of multicomponent reactions to build molecules containing a single ring

• John Andraos

Beilstein J. Org. Chem. 2016, 12, 2420–2442, doi:10.3762/bjoc.12.236

• ], [3 + 2 + 1], and [2 + 2 + 2] partitions given the symmetry elements of the pyridine ring depending on its substitution pattern. Hence, for 2- or 3-substituted pyridines we have six [4 + 1 + 1], twelve [3 + 2 + 1], and two [2 + 2 + 2] target bond dissection maps; whereas, for 4-substituted pyridines

Experimental and theoretical investigations into the stability of cyclic aminals

• Edgar Sawatzky,
• Antonios Drakopoulos,
• Martin Rölz,
• Christoph Sotriffer,
• Bernd Engels and
• Michael Decker

Beilstein J. Org. Chem. 2016, 12, 2280–2292, doi:10.3762/bjoc.12.221

• Information File 1). The results of this study are summarized in Figure 3a–c. Compounds 8a–f (Figure 3a) showed no differences in the extent of hydrolysis depending on their substitution pattern. However, a general trend for all of the test compounds was observed: Compounds 8a–f are stable in a basic or

• structure is highlighted in red. Hydrolysis of the aminal core of tetrahydroquinazolines 1 into the corresponding diamines 2 and aldehydes 3. pH-Stability test of the aminal core toward hydrolysis in dependency of different substitution pattern at (a) the 2-phenyl residue, (b) the N-1 position and (c) the N

The direct oxidative diene cyclization and related reactions in natural product synthesis

• Juliane Adrian,
• Leona J. Gross and
• Christian B. W. Stark

Beilstein J. Org. Chem. 2016, 12, 2104–2123, doi:10.3762/bjoc.12.200

• the trans-isomer from cis-THFs see the examples section below). For all three procedures (using Mn(VII), Ru(VIII) and Os(VIII)) the scope of the reaction is very broad and a large number of 1,5-dienes with any kind of substitution pattern and double bond geometry have been used as substrates [4][5][6

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

• (σm = 0.31 for –NMeCOMe, 0.21 for –NHCOMe, and 0.12 for –OMe [19]). In addition, we expected that the appropriate substitution pattern of amido groups (R3 and R4 in Figure 1) would enable the precise control of the reactivity of triazines in dehydrocondensing reactions. We therefore synthesized

Synthesis and characterization of benzodithiophene and benzotriazole-based polymers for photovoltaic applications

• Desta Gedefaw,
• Marta Tessarolo,
• Margherita Bolognesi,
• Mario Prosa,
• Renee Kroon,
• Wenliu Zhuang,
• Patrik Henriksson,
• Kim Bini,
• Ergang Wang,
• Michele Muccini,
• Mirko Seri and
• Mats R. Andersson

Beilstein J. Org. Chem. 2016, 12, 1629–1637, doi:10.3762/bjoc.12.160

• this class of polymers. Conclusion In conclusion, we reported the synthesis and characterization of two high bandgap polymers based on BDT and Tz units. We showed that the aryl substitution pattern on BDT is an important factor for the reorganization of the polymer in the solid state, affecting the