Supramolecular chemistry: from aromatic foldamers to solution-phase supramolecular organic frameworks

• Zhan-Ting Li

Beilstein J. Org. Chem. 2015, 11, 2057–2071, doi:10.3762/bjoc.11.222

• to the para-position of the ether groups of the benzamide rings of oligomers 15a and 15b to produce 20a and 20b [37], respectively (Scheme 9). 1H NMR dilution experiments in chloroform-d revealed that both compounds formed stable homodimers 20a·20a and 20b·20b, with Kdim being 3.0 × 103 and 2.3 × 105

• M−1, respectively. In contrast, even in nonpolar benzene-d6, the Kdim for the dimerization of benzamide was only 40 M−1. The result again shows that the intramolecular hydrogen bonding of the aromatic amide backbones promoted the appended amide subunits to bind in a cooperative manner by

The facile construction of the phthalazin-1(2H)-one scaffold via copper-mediated C–H(sp²)/C–H(sp) coupling under mild conditions

• Wei Zhu,
• Bao Wang,
• Shengbin Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2015, 11, 1624–1631, doi:10.3762/bjoc.11.177

• hydrazine hydrate and sodium hydroxide. Results and Discussion We initiated our investigation of the direct carbon–carbon coupling of N-(quinolin-8-yl)benzamide (1a) and phenylacetylene (2a). After extensive attempts, 3-benzylidene-2-(quinolin-8-yl)isoindolin-1-one (3a) was formed in 18% yield via the

• -yl)benzamide (1a) as a white solid. Copper-mediated coupling of benzamide 1 and alkynyl substrate 2: The reaction of benzamide 1a with ethynylbenzene (2a) is representative. The dry sealed tube was charged with N-(quinolin-8-yl)benzamide (1a, 99 mg, 0.4 mmol), ethynylbenzene (2a, 82 mg, 0.8 mmol), Cu

• conditions: 1 (0.4 mmol), 2a (0.8 mmol), Cu(OAc)2 (0.4 mmol), K2CO3 (0.8 mmol), DMF (2 mL), 80 °C , 12 h, O2, isolated yield. Copper-mediated reaction of N-(quinolin-8-yl)benzamide with terminal alkynes. Reaction conditions: 1a (0.4 mmol), 2 (0.8 mmol), Cu(OAc)2 (0.4 mmol), K2CO3 (0.8 mmol), DMF (2 mL), 80

The synthesis of active pharmaceutical ingredients (APIs) using continuous flow chemistry

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2015, 11, 1194–1219, doi:10.3762/bjoc.11.134

Natural phenolic metabolites with anti-angiogenic properties – a review from the chemical point of view

• Qiu Sun,
• Jörg Heilmann and
• Burkhard König

Beilstein J. Org. Chem. 2015, 11, 249–264, doi:10.3762/bjoc.11.28

• curcumin analogs. Using this principle, Ahn et al. (2005) [27] left the enone unchanged and prepared various curcumin mimics with asymmetric units bearing alkyl amide, chloro-substituted benzamide, or heteroaromatic amide moieties. These analogs exhibited a stronger anti-angiogenic activity against HUVECs

Cross-dehydrogenative coupling for the intermolecular C–O bond formation

• Igor B. Krylov,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2015, 11, 92–146, doi:10.3762/bjoc.11.13

• the selective replacement of one of the two hydrogen atoms in the ortho-position of acetanilide; the molar ratio of the C- and O-reagents is close to stoichiometric. The acetoxylation (product 42) and methoxylation (product 43) of N-(2-benzoylphenyl)benzamides 41 at the ortho-position of the benzamide

Solution phase synthesis of short oligoribonucleotides on a precipitative tetrapodal support

• Alejandro Gimenez Molina,
• Amit M. Jabgunde,
• Pasi Virta and
• Harri Lönnberg

Beilstein J. Org. Chem. 2014, 10, 2279–2285, doi:10.3762/bjoc.10.237

• minor signal at 14.5 min refers to benzamide. Synthesis of building blocks of the oligoribonucleotide synthesis. (i) TFA, aq THF, 0 °C; (ii) 2-methoxypropene, TsOH, THF; (iii) NH4F, MeOH; (iv) 1-chloro-1-(2-cyanoethoxy)-N,N-diisopropylphosphinamine, DIPEA, DCM; (v) 1. 4-pentynoic acid, DCC, dioxane, 2

Improving the reactivity of phenylacetylene macrocycles toward topochemical polymerization by side chains modification

• Simon Rondeau-Gagné,
• Jules Roméo Néabo,
• Maxime Daigle,
• Katy Cantin and
• Jean-François Morin

Beilstein J. Org. Chem. 2014, 10, 1613–1619, doi:10.3762/bjoc.10.167

• supramolecular nanotubular structures [33][34][35][36][37][38]. Among other things, we have shown that inversion of the amide group configuration (acetanilide vs benzamide) at two different positions on phenylacetylene macrocycles (PAMs) leads to significant changes of the gelation properties and, consequently

• , on the critical parameters needed for polymerization through 1,4-addition reaction [38]. In fact, the acetanilide configuration provides macrocycles which can barely self-assemble in organic solvents while the benzamide configuration yields macrocycles with much greater gelation properties that allow

• possesses two 2-hydroxyethoxy chains and two amide groups in the benzamide configuration while PAM3 contains four of each. It is important to mention that the alcohol chains are positioned for synthetic ease. The synthesis and gelation properties of PAM1 are reported in the literature [39]. PAM1 was used in

Allenylphosphine oxides as simple scaffolds for phosphinoylindoles and phosphinoylisocoumarins

• G. Gangadhararao,
• Ramesh Kotikalapudi,
• M. Nagarjuna Reddy and
• K. C. Kumara Swamy

Beilstein J. Org. Chem. 2014, 10, 996–1005, doi:10.3762/bjoc.10.99

• allenylphosphine oxides/allenylphosphonates. Results and Discussion In order to achieve the anticipated phosphinoylindoles/isocoumarins, we prepared a variety of functionalized propargyl alcohols 1a–m and 2a–j containing an acetamide, benzamide or an ester group at the ortho position (Figure 1) [35][36][37]. Some

Direct and indirect single electron transfer (SET)-photochemical approaches for the preparation of novel phthalimide and naphthalimide-based lariat-type crown ethers

• Dae Won Cho,
• Patrick S. Mariano and
• Ung Chan Yoon

Beilstein J. Org. Chem. 2014, 10, 514–527, doi:10.3762/bjoc.10.47

• results in a close facial approach of the benzamide aromatic rings in 60, which results in intramolecular exciplex formation (Scheme 16). Conclusion Direct and indirect approaches, which rely on the use of SET-promoted photocyclization reactions of α-silyl ether-terminated, polydonor-linked, imides (e.g

An oxidative amidation and heterocyclization approach for the synthesis of β-carbolines and dihydroeudistomin Y

• Suresh Babu Meruva,
• Akula Raghunadh,
• Raghavendra Rao Kamaraju,
• U. K. Syam Kumar and
• P. K. Dubey

Beilstein J. Org. Chem. 2014, 10, 471–480, doi:10.3762/bjoc.10.45

• -ketoamide 9 (Scheme 2). It was possible to limit the formation of benzamide impurity 17 in the reaction to <15% (Table 1); however, we were unable to avoid the formation of 17 under any of the attempted reaction conditions (Scheme 3). The α-ketoamide 9 thus obtained by the oxidative amidation methodology

Micro-flow synthesis and structural analysis of sterically crowded diimine ligands with five aryl rings

• Shinichiro Fuse,
• Nobutake Tanabe,
• Akio Tannna,
• Yohei Konishi and
• Takashi Takahashi

Beilstein J. Org. Chem. 2013, 9, 2336–2343, doi:10.3762/bjoc.9.268

• CCX-1200 (Tokyo Rikakikai Co., Ltd.). Chromatographic separation was performed using a Purif®-α2 (Shoko Scientific Co., Ltd.). Experimental details General procedure for the preparation of imidochlorides: The mixture of N-(1-naphthyl)benzamide and SOCl2 (2 mL/mmol amide) was stirred at 65 °C for 4 h

Synthesis of enantiomerically pure N-(2,3-dihydroxypropyl)arylamides via oxidative esterification

• Akula Raghunadh,
• Satish S More,
• T. Krishna Chaitanya,
• Yadla Sateesh Kumar,
• Suresh Babu Meruva,
• L. Vaikunta Rao and
• U. K. Syam Kumar

Beilstein J. Org. Chem. 2013, 9, 2129–2136, doi:10.3762/bjoc.9.250

• . Results and Discussion Our strategy for an efficient construction of (R) and (S)-N-(2,3-dihydroxypropyl)benzamide (6a) is outlined in Scheme 1. We envisioned that the opening of the phthalimide ring in (S)-3-(1,3-dioxoisoindolin-2-yl)-2-hydroxypropyl benzoate (5a) would afford the desired benzamide 6a

• was concentrated, and the crude mixture was directly used for column chromatography with 100% ethyl acetate. After column chromatographic purification, the product was isolated as a colorless liquid in 94% yield. (S)-N-(2,3-dihydroxypropyl)benzamide (6a): Viscous liquid: yield: 2.45 g (94%); IR (KBr

• [M + 1]; HRMS: calcd for C10H14NO3, 196.0967; found, 196.0974; HPLC: (Chiral PAK-1A (250 × 4.6 mm, column 5.0 u), 1.0 mL/min, 220 nm, n-hexane/IPA 80:20, ambient, 5 µL, retention times: 6.26 min, 100% ee; [α]D25 −12.44 (c 0.75, methanol). (R)-N-(2,3-dihydroxypropyl)benzamide (6b): Viscous liquid

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

• . Importantly, 94 showed superior peak brain uptake (2.08% ID/g at 30 min) and faster brain washout than 58a in normal mice. Expanding on this 2-arylbenzoxazole scaffold, a series of benzamide-substituted 2-arylbenzoxazoles 95a–n was synthesized [71]. A representative synthesis of [123I]95e is shown (Scheme 8B

• target compound. SAR analysis of the compounds indicates that the benzamide moiety is favored at position 5 rather than 6 of the benzoxazole core in terms of binding affinity for Aβ plaques in vitro (Table 9). The best compound was 95e, which had a Ki value of 9.3 nM, but [123I]95e was unable to cross

Design and synthesis of tag-free photoprobes for the identification of the molecular target for CCG-1423, a novel inhibitor of the Rho/MKL1/SRF signaling pathway

• Jessica L. Bell,
• Andrew J. Haak,
• Susan M. Wade,
• Yihan Sun,
• Richard R. Neubig and
• Scott D. Larsen

Beilstein J. Org. Chem. 2013, 9, 966–973, doi:10.3762/bjoc.9.111

• benzophenone is tolerated on the benzamide ring with retention of the biological activity (3, Table 1) [23]. In addition to a PG, we needed a suitable linking functionality for attachment of a clickable acetylene group. Preliminary work (data not shown) established that an ether (versus amide) linker was

Synthesis of skeletally diverse alkaloid-like molecules: exploitation of metathesis substrates assembled from triplets of building blocks

• Sushil K. Maurya,
• Mark Dow,
• Stuart Warriner and
• Adam Nelson

Beilstein J. Org. Chem. 2013, 9, 775–785, doi:10.3762/bjoc.9.88

• diastereoiomers; following column chromatography, the major diastereomer 22 was obtained in 70% yield, and was converted into the corresponding amino alcohol 23. The configuration of the amino alcohol 23 was determined by conversion into the corresponding benzamide and comparison with racemic and enantiomerically

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

Palladium-catalyzed C–N and C–O bond formation of N-substituted 4-bromo-7-azaindoles with amides, amines, amino acid esters and phenols

• Rajendra Surasani,
• Dipak Kalita,
• A. V. Dhanunjaya Rao and
• K. B. Chandrasekhar

Beilstein J. Org. Chem. 2012, 8, 2004–2018, doi:10.3762/bjoc.8.227

• substrates (Table 1). N-Benzyl-4-bromo-7-azainole (1-benzyl-4-bromo-1H-pyrrolo[2,3-b]pyridine, 1e) and benzamide (2a) were chosen as model substrates to find the suitable palladium-mediated coupling of amides with N-protected 4-bromo-7-azaindole 1. After extensive screening, we found that the combination of

• obtained (Table 1, entries 6 and 7). When tertiary ligand PCy3 (L4) was used as a ligand for the cross-coupling reaction no product formation was observed (Table, entry 5). Cross-coupling reaction of N-benzyl-4-bromo-7-azaindole (1e) and benzamide (2a) with other bases, e.g., K2CO3 and K3PO4, by using Pd

• conditions in dioxane [57]. The optimized reaction conditions worked well with benzamide (2a) (Table 2, entry 3) and phenylsulfonamide (2b) (Table 2, entry 4) to obtained a good yield. A cyclic secondary amide (lactam) 2c also reacted efficiently (Table 2, entry 5). The methodology works equally well with 2

On the control of secondary carbanion structure utilising ligand effects during directed metallation

• Andrew E. H. Wheatley,
• Jonathan Clayden,
• Ian H. Hillier,
• Alison Campbell Smith,
• Mark A. Vincent,
• Laurence J. Taylor and
• Joanna Haywood

Beilstein J. Org. Chem. 2012, 8, 50–60, doi:10.3762/bjoc.8.5

• towards the study of the competition between the ortho and lateral deprotonation of 2-alkylated benzamide substrates. Hence, 2-ethylated analogues of 1-H and 2-H (3-H and 4-H, respectively; Scheme 2) have been treated with t-BuLi in the presence of either PMDTA (N,N,N′,N″,N″-pentamethyldiethylenetriamine

Directed aromatic functionalization in natural-product synthesis: Fredericamycin A, nothapodytine B, and topopyrones B and D

• Charles Dylan Turner and
• Marco A. Ciufolini

Beilstein J. Org. Chem. 2011, 7, 1475–1485, doi:10.3762/bjoc.7.171

• benzamide 56 with sec-BuLi/TMEDA (1.05 equiv, 3 h, −78 °C) and addition of the resulting organolithium agent to 65 was presumed to form the alkoxide 66. In situ treatment of 66 with t-BuLi induced bromine–lithium exchange and cyclization of organolithium species 67 to a product that was believed to be 68

• detailed in the isolation paper [90][91]. An unexpected problem materialized when the foregoing sequence was transposed to the case of topopyrone B, the synthesis of which required the execution of the same operations starting with benzamide 57. Surprisingly, this material resisted deprotonation under

Synthesis of enantiomerically enriched (R)-¹³C-labelled 2-aminoisobutyric acid (Aib) by conformational memory in the alkylation of a derivative of L-alanine

• Stephen P. Fletcher,
• Jordi Solà,
• Dean Holt,
• Robert A. Brown and
• Jonathan Clayden

Beilstein J. Org. Chem. 2011, 7, 1304–1309, doi:10.3762/bjoc.7.152

• Ar–CO axis as a chiral “aide-mémoire” for translating the configuration of the starting amino acid into the configuration of the product. We have previously employed benzamide and naphthamide Ar–CO axes in “chiral memory” processes [52][53]. Kouklovsky reported the enantioselective alkylation of

NMR studies of anion-induced conformational changes in diindolylureas and diindolylthioureas

• Damjan Makuc,
• Jennifer R. Hiscock,
• Mark E. Light,
• Philip A. Gale and
• Janez Plavec

Beilstein J. Org. Chem. 2011, 7, 1205–1214, doi:10.3762/bjoc.7.140

• of DMSO-d6 at δ 2.50 ppm for 1H (297.801 MHz) and δ 39.50 ppm for 13C (76.190 MHz), while 15N (30.188 MHz) chemical shifts were referenced relative to external benzamide (δ 103.55 ppm). Individual resonances were assigned on the basis of their chemical shifts, signal intensities, multiplicity of

A practical two-step procedure for the preparation of enantiopure pyridines: Multicomponent reactions of alkoxyallenes, nitriles and carboxylic acids followed by a cyclocondensation reaction

• Christian Eidamshaus,
• Roopender Kumar,
• Mrinal K. Bera and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2011, 7, 962–975, doi:10.3762/bjoc.7.108

• (eluent:hexane/EtOAc 3:1) to give 64 as a pale yellow oil (300 mg, 73%). (S)-N-{1-[1-(tert-Butyldimethylsiloxy)ethyl]-2-methoxy-3-oxo-but-1-enyl}benzamide (64) 1H NMR (500 MHz, CDCl3) δ 0.07, 0.11, 0.88 (3 s, 3H, 3H, 9H, OTBS), 1.46 (d, J = 6.4 Hz, 3H, 2’’-H), 2.32 (s, 3H, 4’-H), 3.51 (s, 3H, OMe), 5.33 (q, J

The arene–alkene photocycloaddition

• Ursula Streit and
• Christian G. Bochet

Beilstein J. Org. Chem. 2011, 7, 525–542, doi:10.3762/bjoc.7.61

• the intramolecular photocycloaddition of a cinnamoylamide and a benzamide moiety (Scheme 32) [97]. This reaction is very efficient and leads to high yields of the bicyclo[2.2.2]octadiene derivative. In this example, the cinnamoylamide is sensitized by benzil to its triplet excited-state. The proposed

Approaches towards the synthesis of 5-aminopyrazoles

• Ranjana Aggarwal,
• Vinod Kumar,
• Rajiv Kumar and
• Shiv P. Singh

Beilstein J. Org. Chem. 2011, 7, 179–197, doi:10.3762/bjoc.7.25

• the starting material (Scheme 8). In this reaction, compound 25 was readily hydrolyzed to afford the β-ketonitrile derivative, i.e., 4-(1-cyano-2-oxoethyl)benzamide 26 which reacted efficiently with hydrazines to give the corresponding 5-aminopyrazoles 27. Subsequent cleavage from the resin afforded 5

• , imidazo[1,2-b]pyrazol-2-ones. Synthesis of 5-amino-3-(pyrrol-2-yl)pyrazole-4-carbonitrile. Synthesis of N-(1,3-diaryl-1H-pyrazol-5-yl)benzamide. Synthesis of 3,7-bis(arylazo)-6-methyl-2-phenyl-1H-imidazo[1,2-b]pyrazoles. Synthesis of 3,5-diaminopyrazole. Synthesis of 5-amino-4-cyanopyrazole and 5-amino-3

Self-assembly and semiconductivity of an oligothiophene supergelator

• Pampa Pratihar,
• Suhrit Ghosh,
• Vladimir Stepanenko,
• Sameer Patwardhan,
• Ferdinand C. Grozema,
• Laurens D. A. Siebbeles and
• Frank Würthner

Beilstein J. Org. Chem. 2010, 6, 1070–1078, doi:10.3762/bjoc.6.122

• (dodecyloxy)benzamide (6). Compound 4 (2.94 mmol) was dissolved in 5 mL dry CH2Cl2 and cooled in an ice-bath. To this cold solution, 4 mL triethylamine was added slowly. The resulting mixture was ice-cooled for an additional 10 minutes and then a solution of compound 5 in 10 mL dry CH2Cl2 was added dropwise