Synthesis of benzannelated sultams by intramolecular Pd-catalyzed arylation of tertiary sulfonamides

• Valentin A. Rassadin,
• Mirko Scholz,
• Anastasiia A. Klochkova,
• Armin de Meijere and
• Victor V. Sokolov

Beilstein J. Org. Chem. 2017, 13, 1932–1939, doi:10.3762/bjoc.13.187

• , the tertiary analogue 5 underwent cyclization smoothly and rapidly (1 h) under the same conditions to furnish the benzannelated sultam 6 in 78% yield (Scheme 2). Thus, in order to enable the preparation of arene-annelated tertiary sultams of type 6 along this route, an effective and versatile access

• approach to arene-annelated sultams. Pd-catalyzed cyclization of (2-iodophenyl)sulfonamides 3 and 5. Preparation of 4-methoxybenzyl-protected methyl 2-(N-o-iodoarylsulfamoyl)acetates 8. Reagents and conditions A: MeO2CCH2SO2Cl (2a), Py, MeCN, 60 °C, 48 h; conditions B: MeO2CCH2SO2Cl (2a), PhNEt2, CH2Cl2

• , rt, 20 h; conditions C: EtO2CCH(Me)SO2Cl (2b), Py, MeCN, 60 °C, 48 h. Synthesis of arene-annelated sultams 10 by Pd-catalyzed intramolecular arylation of a C–H acidic methylene group. Palladium-catalyzed transformation of N-(2-iodophenyl)-N-(4-methoxybenzyl-benzylsulfonamide 12. Ar = 4-MeOC6H4; a

Mechanochemical synthesis of small organic molecules

• Tapas Kumar Achar,
• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

• ], carbon–heteroatom [41][42], metal–ligand coordination bonds [43], non-covalent interactions such as hydrogen bonds or π–π arene stacking interactions [44], etc. are popularly known in literature. In this review the efforts are given towards documentation of various mechanochemical reactions like organic

• palladium-catalyzed site selective mechanochemical dehydrogenative C–H/C–H arylation between oxime and arene moiety for the construction of Csp2–Csp2 bond with high para-selectivity of arene component via LAG. Using 10 mol % of Pd(OAc)2, 2.0 equiv of Na2S2O8 and 1.0 equiv TfOH the biaryls were synthesized

• using dioxazolone as the amide source under ball milling conditions (Scheme 54). Using 5 mol % of Rh catalyst, 20 mol % of AgSbF6 and 20 mol % of AgOAc they have successfully achieved up to 99% of ortho-amidation product with diversely substituted arene moiety [186]. Recently Bolm and co-workers

Iodoarene-catalyzed cyclizations of N-propargylamides and β-amidoketones: synthesis of 2-oxazolines

• Somaia Kamouka and
• Wesley J. Moran

Beilstein J. Org. Chem. 2017, 13, 1823–1827, doi:10.3762/bjoc.13.177

• studied with various arylamide and alkyne substituents. All functional groups were well tolerated apart from an alkyne terminated with an alkyl substituted arene which led to a diminished yield of product, i.e., 6g. The mechanism of this cyclization is proposed to proceed though activation of the alkyne

An effective Pd nanocatalyst in aqueous media: stilbene synthesis by Mizoroki–Heck coupling reaction under microwave irradiation

• Carolina S. García,
• Paula M. Uberman and
• Sandra E. Martín

Beilstein J. Org. Chem. 2017, 13, 1717–1727, doi:10.3762/bjoc.13.166

• yields. When an ortho-substituted arene, 1g, was used, product 9 was obtained in only moderate yield compared with para-substituted stilbene 8 synthesized under the same conditions (entries 6 and 7, Table 2). This behavior can be explained by the steric hindrance caused by the methylene group in ortho

Oxidative dehydrogenation of C–C and C–N bonds: A convenient approach to access diverse (dihydro)heteroaromatic compounds

• Santanu Hati,
• Ulrike Holzgrabe and
• Subhabrata Sen

Beilstein J. Org. Chem. 2017, 13, 1670–1692, doi:10.3762/bjoc.13.162

• quinazolinones. A putative mechanism involved the homolysis of DTBP to generate tert-butoxide radicals, which in turn abstracts a proton radical from the methyl(hetero)arene to facilitate the formation of a benzylic radical. The benzylic radical couples with o-aminobenzylamide to generate H. It then interacts

Sustainable synthesis of 3-substituted phthalides via a catalytic one-pot cascade strategy from 2-formylbenzoic acid with β-keto acids in glycerol

• Lina Jia and
• Fuzhong Han

Beilstein J. Org. Chem. 2017, 13, 1425–1429, doi:10.3762/bjoc.13.139

• limitations of this one-pot cascade aldol/cyclization system. Typical results are shown in Scheme 2. The annulation proceeded smoothly with β-keto acids 2 bearing diverse arene substituents to provide the corresponding isobenzofuran-1(3H)-ones in moderate to excellent yields. For para-substituted β-keto acids

Regioselective (thio)carbamoylation of 2,7-di-tert-butylpyrene at the 1-position with iso(thio)cyanates

• Anna Wrona-Piotrowicz,
• Marzena Witalewska,
• Janusz Zakrzewski and
• Anna Makal

Beilstein J. Org. Chem. 2017, 13, 1032–1038, doi:10.3762/bjoc.13.102

• .) [1][2][3][4][5][6][7]. Since 1 is an electron-rich arene, aromatic electrophilic substitution seems to be the simplest method for this purpose, and a plethora of substituted pyrenes have been synthesized in this way [1]. As is shown in Figure 1, the most reactive in such reactions are positions 1, 3

• with the arene ring of the protonated aromatic iso(thio)cyanate during formation of the Wheland complex, which may direct the electrophilic attack partly to the 4-position of the pyrene moiety. To the best of our knowledge, the reaction reported here is the first example of a C1-selective substitution

Transition-metal-catalyzed synthesis of phenols and aryl thiols

• Yajun Liu,
• Shasha Liu and
• Yan Xiao

Beilstein J. Org. Chem. 2017, 13, 589–611, doi:10.3762/bjoc.13.58

• reoxidation of Pd(0) as the reaction couldn't proceed with a stoichiometric amount of Pd(OAc)2 under argon. In 2012, the Rao group and the Dong group simultaneously reported a palladium catalyzed ortho-hydroxylation of aryl ketones, and thus further broadened the directing groups of arene substrates [70][71

Correction: Inherently chiral calix[4]arenes via oxazoline directed ortholithiation: synthesis and probe of chiral space

• Simon A. Herbert,
• Laura J. van Laeren,
• Dominic C. Castell and
• Gareth E. Arnott

Beilstein J. Org. Chem. 2017, 13, 347–347, doi:10.3762/bjoc.13.38

• Simon A. Herbert Laura J. van Laeren Dominic C. Castell Gareth E. Arnott Department of Chemistry and Polymer Science, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa 10.3762/bjoc.13.38 Keywords: calix[4]arene; inherently chiral; ortholithiation; oxazoline; Tsuji–Trost; In

New approaches to organocatalysis based on C–H and C–X bonding for electrophilic substrate activation

• Pavel Nagorny and
• Zhankui Sun

Beilstein J. Org. Chem. 2016, 12, 2834–2848, doi:10.3762/bjoc.12.283

• of an electron-withdrawing group into the aryl ring (i.e., NO2, CN, CF3, etc.) could significantly enhance this binding and result in stronger hydrogen bonds between the arene and the anion. Thus, the gas-phase binding energy of the nitrobenzene and chloride anion complex containing two C–H hydrogen

• L15 were proposed to form additional C–H hydrogen bonds between arene or α-halogenated acetyl groups and the carbonyl of lactide. X-ray crystallographic analysis and molecular modeling provided the evidence of such interactions in solid state, and the titration studies established weak binding (Ka ≈ 1

cis-Diastereoselective synthesis of chroman-fused tetralins as B-ring-modified analogues of brazilin

• Dimpee Gogoi,
• Runjun Devi,
• Pallab Pahari,
• Bipul Sarma and
• Sajal Kumar Das

Beilstein J. Org. Chem. 2016, 12, 2816–2822, doi:10.3762/bjoc.12.280

• Abstract We have synthesized a series of cis-6a,7,8,12b-tetrahydro-6H-naphtho[2,1-c]chromen-6a-ols as B-ring-modified analogues of (±)-brazilin. A completely regio- and cis-diastereoselective intramolecular Friedel–Crafts epoxy–arene cyclization of 1-tetralone-derived glycidyl ethers catalyzed by Brønsted

• been reductively removed by a diastereoselective method which should be useful in future for preparing libraries of chroman-fused tetralins with trans-stereochemistry at the ring junction. Keywords: brazilin; chroman; epoxy-arene cyclization; natural-product-like molecules; tetralin; Findings The

• studied during the past 15 years [19]. Moreover, on many occasions natural product-like molecules exhibit more potent biological activities than the parent natural products [20]. Meanwhile, the intramolecular Friedel–Crafts epoxy–arene (IFCEA) cyclization has been well-established as a powerful tool for

Palladium-catalyzed ring-opening reactions of cyclopropanated 7-oxabenzonorbornadiene with alcohols

• Katrina Tait,
• Oday Alrifai,
• Rebecca Boutin,
• Jamie Haner and
• William Tam

Beilstein J. Org. Chem. 2016, 12, 2189–2196, doi:10.3762/bjoc.12.209

• ). Syn-stereoisomeric products 2 and 3 can be obtained using rhodium [14], palladium [15], or nickel [16] catalysts with an arene nucleophile and when palladium [17] or nickel [18] are used with an alkyl nucleophile. Recently, it was shown that the syn-stereoisomeric product 4 could be obtained through

• both bridgehead positions was first investigated. With a methyl group at both bridge head positions, the yield was decreased to 40% at 90 °C (Table 3, entry 1). Substitution on the arene portion of cyclopropanated oxabenzonorbornadiene 8a was investigated. p-Methoxy-substituted 8c underwent minimal

• halide substitution on the arene was also investigated in the ortho position which decreased the yield to 37% (Table 3, entry 4). The scope of the reaction was then extended to include examples of unsymmetrical functionalized substrates 8f–j bearing substituents at the C1 position. With a substituent at

Superelectrophilic activation of 5-hydroxymethylfurfural and 2,5-diformylfuran: organic synthesis based on biomass-derived products

• Dmitry S. Ryabukhin,
• Dmitry N. Zakusilo,
• Mikhail O. Kompanets,
• Anton A.Tarakanov,
• Irina A. Boyarskaya,
• Tatiana O. Artamonova,
• Mikhail A. Khohodorkovskiy,
• Iosyp O. Opeida and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2016, 12, 2125–2135, doi:10.3762/bjoc.12.202

• temperature for 1–24 h gives rise to 5-arylmethylfurfurals (yields of 17–91%) and 2-arylmethyl-5-(diarylmethyl)furans (yields of 10–37%). The formation of these two types of reaction products depends on the nucleophilicity of the arene. The same reactions under the action of acidic zeolites H-USY in high

• the substrate (arene) molecules. We also varied reaction conditions (time, amount of arene) in TfOH to check yields of compounds 3 and 4. In general, increasing the reaction time up to 3–24 h led to an increase in the yield of furans 4 and a decreased yield of compounds 3 (compare pairs of entries in

• , 11, 13, and 15). The coordination of aluminum halides with the aldehyde group results in the activation of one of the aldehyde groups, catalyzing the reaction subsequently with two arene molecules resulting in the 1,1-diarylated product. The second aldehyde group does not take part in the reaction

Practical synthetic strategies towards lipophilic 6-iodotetrahydroquinolines and -dihydroquinolines

• David R. Chisholm,
• Garr-Layy Zhou,
• Ehmke Pohl,
• Roy Valentine and
• Andrew Whiting

Beilstein J. Org. Chem. 2016, 12, 1851–1862, doi:10.3762/bjoc.12.174

• literature [13]. An initial investigation with the corresponding bromides indicated that these were unreactive towards many cross-coupling methodologies, presumably due to the highly electron-rich arene [14]. Reactions such as the Sonogashira coupling, for example, often required high catalyst loadings

Amidofluorene-appended lower rim 1,3-diconjugate of calix[4]arene: synthesis, characterization and highly selective sensor for Cu²⁺

• Rahman Hosseinzadeh,
• Mohammad Nemati,
• Reza Zadmard and
• Maryam Mohadjerani

Beilstein J. Org. Chem. 2016, 12, 1749–1757, doi:10.3762/bjoc.12.163

• Basic Science, University of Mazandaran, Babolsar, Iran 10.3762/bjoc.12.163 Abstract Functionalization of calix[4]arene with amidofluorene moieties at the lower rim led to formation of the 1,3-diconjugate of calix[4]arene L as a novel fluorescent chemosensor for Cu2+. The receptor molecule L exhibited

• of 9.6 × 10−8 M. Keywords: calix[4]arene; chemosensor; copper ions; fluorene; fluorescence; Introduction Owing to the substantial role of fluorescent chemosensors in biological, environmental, and chemical processes, their design and synthesis, especially for detection of metal ions has attracted

• supramolecular structures, especially calixarene derivatives, has been an appealing field for research [14]. Calixarene has been considered as an effective molecular scaffold in the improvement of fluorescent and chromogenic sensors, especially for metal-ion recognition [14][15]. Calix[4]arene derivatives having

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

Experimental and theoretical insights in the alkene–arene intramolecular π-stacking interaction

• Valeria Corne,
• Ariel M. Sarotti,
• Carmen Ramirez de Arellano,
• Rolando A. Spanevello and
• Alejandra G. Suárez

Beilstein J. Org. Chem. 2016, 12, 1616–1623, doi:10.3762/bjoc.12.158

• all noncovalent interactions, π-stacking is perhaps the less well understood, although its application in materials sciences, enzyme design and template-directed synthesis have had a dramatic growth, mainly for arene–arene interactions [1][2][3][4][5][6][7][8]. In particular, the use of π–π overlap as

• , spectroscopic and computational evidence of the structurally related chiral acrylates to get new insights into the alkene–arene intramolecular interaction. Besides, it was evaluated the effect of the electron density of the aromatic counterpart and its influence on the asymmetric inductive capacity of the

• and aromatic groups in a face-to-edge arrangement, with a dihedral angle of 73.8(2)° between the groups’ mean planes (Figure 6 and Supporting Information File 1). The distance between the centroid of the arene and the middle point of the C=C double bond is 6.48 Å. The conformation found in the solid

Ring-whizzing in polyene-PtL₂ complexes revisited

• Oluwakemi A. Oloba-Whenu,
• Thomas A. Albright and
• Chirine Soubra-Ghaoui

Beilstein J. Org. Chem. 2016, 12, 1410–1420, doi:10.3762/bjoc.12.135

• arene–Pt(PR3)2 structures in the literature [47][48] and both have η2 geometries. The barrier for ring whizzing in (CF3)6C6–Pt(PEt3)2 has been measured to be ≈11 kcal/mol [41]. One member of the LUMO e1g set in benzene has a large overlap with the b2 ML2 MO. The computed ground state structure for η2

Synthesis of 2-substituted tetraphenylenes via transition-metal-catalyzed derivatization of tetraphenylene

• Shulei Pan,
• Hang Jiang,
• Yanghui Zhang,
• Yu Zhang and
• Dushen Chen

Beilstein J. Org. Chem. 2016, 12, 1302–1308, doi:10.3762/bjoc.12.122

• into other functionalities [58][59]. The Larock group reported a novel Pd-catalyzed addition of nitriles to an arene C–H bond for the synthesis of aryl ketones [60][61]. Following the Larock’s conditions, we investigated the carbonylation of tetraphenylene (1) and the carbonylated product 5a was

Palladium-catalyzed picolinamide-directed iodination of remote ortho-C−H bonds of arenes: Synthesis of tetrahydroquinolines

• William A. Nack,
• Xinmou Wang,
• Bo Wang,
• Gang He and
• Gong Chen

Beilstein J. Org. Chem. 2016, 12, 1243–1249, doi:10.3762/bjoc.12.119

• . Arene substrates bearing strongly electron-donating substituents typically gave substantial amounts of undesired iodinated side products via competing innate SEAr processes, and arene substrates bearing strongly electron-withdrawing substituents were often unreactive. Herein, we report our development

• iodination, and undirected SEAr iodination to quickly access THQs 27–30 bearing iodo groups at different positions on the arene ring [40][41][42]. Ortho-diiodinated product 4 was obtained from 2 in 69% yield using optimized Pd-catalyzed ε-C–H iodination conditions, and Cu-catalyzed C–N cyclization of 4 gave

Reactions of N,3-diarylpropiolamides with arenes under superelectrophilic activation: synthesis of 4,4-diaryl-3,4-dihydroquinolin-2(1H)-ones and their derivatives

• Larisa Yu. Gurskaya,
• Diana S. Belyanskaya,
• Dmitry S. Ryabukhin,
• Denis I. Nilov,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2016, 12, 950–956, doi:10.3762/bjoc.12.93

• , 0.5 h. Some optimization of the reaction on minimization of the usage of arenes and TfOH were performed. The amount of arene may be decreased to 5 equivalents. But, concerning the use of a lower amount of TfOH, for instance, running the reaction in CH2Cl2 solution led to a dramatic decrease of the

• amides 1k,o gave regioselectively only 7-substituted quinolinones 2c,f (Table 1, entries 7, 8, 14 and 15) and 6,7-disubstituted quinolinones 2k,o (Table 1, entries 25 and 29), respectively. Concerning the arene component of this reaction, apart from benzene, chlorobenzene and 1,2-dichlorobenzene it may

• , perhaps, dication D1 was not reactive due to the bigger spatial volume of the methyl substituent in the N-acyl group compared to hydrogen of the N-formyl one in C1, that hampered the reaction with arene molecule. Conclusion A simple and effective approach to 4,4-diaryl-3,4-dihydroquinolin-2-(1H)-ones

A convenient route to symmetrically and unsymmetrically substituted 3,5-diaryl-2,4,6-trimethylpyridines via Suzuki–Miyaura cross-coupling reaction

• Dariusz Błachut,
• Joanna Szawkało and
• Zbigniew Czarnocki

Beilstein J. Org. Chem. 2016, 12, 835–845, doi:10.3762/bjoc.12.82

• substituted arene rings. An elegant approach to variously arylated pentaarylpyridines was recently proposed by Reimann et al. [60]. The final outcome of such a procedure is governed by many factors, including differences in site reactivity of polyhaloarenes (concerning both regio- and chemoselectivity

Iridium/N-heterocyclic carbene-catalyzed C–H borylation of arenes by diisopropylaminoborane

• Mamoru Tobisu,
• Takuya Igarashi and
• Naoto Chatani

Beilstein J. Org. Chem. 2016, 12, 654–661, doi:10.3762/bjoc.12.65

• 1g afforded 17-B in 48% isolated yield even when the reaction was conducted under neat conditions (Table 3, entry 1) (see the Supporting Information File 1 for details on the optimization for the borylation of benzene). Borylation was relatively independent of the electronic nature of the arene

• 1g.a Scope of the heteroarene substrates.a Scope of the arene substrates.a Supporting Information Supporting Information File 50: Experimental procedures, data for optimization studies and copies of 1H and 13C NMR spectra. Acknowledgements This work was supported by a Grant-in-Aid for Scientific

Copper-mediated arylation with arylboronic acids: Facile and modular synthesis of triarylmethanes

• H. Surya Prakash Rao and
• A. Veera Bhadra Rao

Beilstein J. Org. Chem. 2016, 12, 496–504, doi:10.3762/bjoc.12.49

• arene aldehydes followed by substitution of the resulting hydroxy group with another electron-rich aromatic compound (Scheme 1A, method 2) [36][37][38][39]. Both of the approaches are limited in scope and suffer from drawbacks such as (a) electron-rich aromatic systems that are required as nucleophiles

My maize and blue brick road to physical organic chemistry in materials

• Anne J. McNeil

Beilstein J. Org. Chem. 2016, 12, 229–238, doi:10.3762/bjoc.12.24

• : to evaluate the effect of through-space (rather than through-bond) interactions on a conjugated polymer’s properties. During this project I synthesized some of the most beautiful molecules I have ever seen, with one and two cofacial arenes surrounding the central arene of the monomer (Figure 1) [14