Catalytic asymmetric synthesis of biologically important 3-hydroxyoxindoles: an update

• Bin Yu,
• Hui Xing,
• De-Quan Yu and
• Hong-Min Liu

Beilstein J. Org. Chem. 2016, 12, 1000–1039, doi:10.3762/bjoc.12.98

• of 10% of catalyst loading. Interestingly, the protocol employed gem-diols as equivalents of fluorinated aryl/alkyl methyl ketone enolates for the C–C bond formation accompanied the release of trifluoroacetate. This method showed a broad substrate scope including gem-diols with phenyl rings

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

• . Recently, we reported a copper-catalyzed C–C bond formation by substitution of the labile C(4)SMe group in 4H-chromenes or C(3)–OH in isoindolinones with aryl/alkenyl groups by employing the corresponding boronic acids [51][52]. Continuing these efforts, we designed a copper-catalyzed synthesis of a

• PhCu(OTf) (15) and B(OH)2(OTf) [61]. The intermediate 15 then reacts with diphenylmethanol 9 to provide the intermediate 16. Formation of the intermediate 16 can be attributed to Lewis acidic characteristics of 15 and Lewis basic characteristics of diphenylmethanol (9a). The crucial C–C bond formation

• provide triarylmethanes. However, when we employed 2,6-dimethoxyphenylboronic acid 10l, surprisingly, we isolated the triarylmethane 11l, in which the C–C bond formation took place on the C(3) carbon of the 2,6-dimethoxyphenylboronic acid instead of the C(1) carbon, as illustrated in 11m (Scheme 4

Cascade alkylarylation of substituted N-allylbenzamides for the construction of dihydroisoquinolin-1(2H)-ones and isoquinoline-1,3(2H,4H)-diones

• Ping Qian,
• Bingnan Du,
• Wei Jiao,
• Haibo Mei,
• Jianlin Han and
• Yi Pan

Beilstein J. Org. Chem. 2016, 12, 301–308, doi:10.3762/bjoc.12.32

• -substituted heterocycles has been considered as an efficient organic synthetic strategy, which is often featured by a new ring and dual C–C bond formation in one process [35][36][37][38][39][40][41][42]. Recently, the group of Liu reported a cascade alkylarylation of N-alkyl-N-phenylacryamide with simple

N-Methylphthalimide-substituted benzimidazolium salts and PEPPSI Pd–NHC complexes: synthesis, characterization and catalytic activity in carbon–carbon bond-forming reactions

• Senem Akkoç,
• Yetkin Gök,
• İlhan Özer İlhan and
• Veysel Kayser

Beilstein J. Org. Chem. 2016, 12, 81–88, doi:10.3762/bjoc.12.9

• arylation (for 5–8) reactions. As catalysts, they demonstrated a highly efficient route for the formation of asymmetric biaryl compounds even though they were used in very low loading. For example, all compounds displayed good catalytic activity for the C–C bond formation of 4-tert-butylphenylboronic acid

• used as a substrate with catalyst 6, sp2–sp2 C–C bond formation with 2-n-butylfuran was achieved with a yield of 49% in just 1 h (Table 1, entry 5). The product was obtained in a much lower yield when the same reaction was carried out with 5 as a catalyst. Compounds 7 and 8 as catalysts were displaying

• better results than complexes 5 and 6 for the same reaction (Table 1, entries 6 and 7). When we employed electron-neutral bromobenzene as a substrate instead of 4-bromoacetophenone, C–C bond formation (2-butyl-5-phenylthiophene) was achieved in 97% yield using catalyst 8 at 110 °C with a reaction time of

Recent advances in copper-catalyzed asymmetric coupling reactions

• Fengtao Zhou and
• Qian Cai

Beilstein J. Org. Chem. 2015, 11, 2600–2615, doi:10.3762/bjoc.11.280

• different products: the SN2-product or the SN2’-product (Scheme 24). Usually, SN2’ regioselective allylic substitutions, which create a new stereogenic center, are more valuable. Methods that allow the SN2’ regioselective C–C bond formation have been extensively studied over the past years. In contrast to

Versatile synthesis and biological evaluation of novel 3’-fluorinated purine nucleosides

• Hang Ren,
• Haoyun An,
• Paul J. Hatala,
• William C. Stevens Jr,
• Jingchao Tao and
• Baicheng He

Beilstein J. Org. Chem. 2015, 11, 2509–2520, doi:10.3762/bjoc.11.272

• ’-deoxy-3’-fluororibosides 16–20. Synthesis of 2-aminopurine 3’-deoxy-3’-fluororibosides 21–23. C–C bond formation by Stille and Suzuki cross-coupling. Antitumor activity of newly synthesized compounds. Supporting Information Supporting Information File 444: Experimental procedures, characterization data

Copper-catalyzed arylation of alkyl halides with arylaluminum reagents

• Bijay Shrestha and
• Ramesh Giri

Beilstein J. Org. Chem. 2015, 11, 2400–2407, doi:10.3762/bjoc.11.261

• excellent yields. Keywords: alkylation; arylalkanes; copper; cross-coupling; organoaluminum; Introduction Cross-coupling reactions represent one of the most important transformation for carbon–carbon (C–C) bond formation in organic synthesis [1][2][3][4][5][6][7][8][9]. These reactions, typically

Ruthenium indenylidene “1^st generation” olefin metathesis catalysts containing triisopropyl phosphite

• Stefano Guidone,
• Fady Nahra,
• Alexandra M. Z. Slawin and
• Catherine S. J. Cazin

Beilstein J. Org. Chem. 2015, 11, 1520–1527, doi:10.3762/bjoc.11.166

• -type ligands. Keywords: 1st generation; indenylidene; metathesis; phosphite; ruthenium; Introduction The olefin metathesis reaction is a powerful tool for C–C bond formation in the synthesis of highly valuable organic compounds [1][2][3][4]. Protocols involving W-, Mo- and Ru-based pre-catalysts can

Cathodic hydrodimerization of nitroolefins

• Michael Weßling and
• Hans J. Schäfer

Beilstein J. Org. Chem. 2015, 11, 1163–1174, doi:10.3762/bjoc.11.131

• the easy access to nitroolefins in large variety, the C–C bond formation with the introduction of two nitro groups in a 1,4-distance and the conversions of the nitro group by reduction to oximes and amines, the conversion into aldehydes and ketones via the Nef reaction and base catalyzed condensations

• C–C bond formation can lead to α,α-, α,β- and ß,ß-coupled products. The 1H NMR spectra and MS data support in all cases a ß,ß-coupling. A α,β- or a α,α-coupling would lead to the occurrence of methyl singlets or non-coupled benzylic protons. Such signals were not observed in the spectra of the

• hydrodimers. The stereochemistry of the hydrodimer results from a β,ß-C–C bond formation and from a α,δ-diprotonation, which creates a dimer with four stereocenters with the exception of dimer 3, which has only two stereocenters. This means 23 diastereomers can be formed, which are decreased to six

Multivalent polyglycerol supported imidazolidin-4-one organocatalysts for enantioselective Friedel–Crafts alkylations

• Tommaso Pecchioli,
• Manoj Kumar Muthyala,
• Rainer Haag and
• Mathias Christmann

Beilstein J. Org. Chem. 2015, 11, 730–738, doi:10.3762/bjoc.11.83

• organocatalysis has allowed for selective C–C bond formation by using small organic molecules [25][26][27][28][29][30][31]. In contrast to metal complexes, chiral or achiral organocatalysts are easily attached on supports. They do not suffer from metal leaching and they can be reused more readily [32][33][34][35

Novel biphenyl-substituted 1,2,4-oxadiazole ferroelectric liquid crystals: synthesis and characterization

• Mahabaleshwara Subrao,
• Dakshina Murthy Potukuchi,
• Girish Sharada Ramachandra,
• Poornima Bhagavath,
• Sangeetha G. Bhat and
• Srinivasulu Maddasani

Beilstein J. Org. Chem. 2015, 11, 233–241, doi:10.3762/bjoc.11.26

• 5a is borylated under Miyaura coupling conditions [31][32][33][34] with bis(pinacolato)diborane (pin2b2) to give benzyl 4-(5-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1,2,4-oxadiazol-3-yl)benzoate (6a), which facilitated the C–C bond formation of a biphenyl group. The same methodology

Sequential decarboxylative azide–alkyne cycloaddition and dehydrogenative coupling reactions: one-pot synthesis of polycyclic fused triazoles

• Kuppusamy Bharathimohan,
• Thanasekaran Ponpandian,
• A. Jafar Ahamed and
• Nattamai Bhuvanesh

Beilstein J. Org. Chem. 2014, 10, 3031–3037, doi:10.3762/bjoc.10.321

• several advantages over the classical C–C bond formation method including the stability and preparation of the starting material and the non-hazardous byproducts. In 2011, Kolarovič et al. [6] first reported the copper-catalyzed decarboxylative [3 + 2] cycloaddition reaction of 2-alkynoic acid with

Recent advances in the electrochemical construction of heterocycles

• Robert Francke

Beilstein J. Org. Chem. 2014, 10, 2858–2873, doi:10.3762/bjoc.10.303

• method for the synthesis of oxindoles and 3-oxotetrahydroisoquinolines 47 via intramolecular cyclization under C–C-bond formation was reported by Atobe, Fuchigami et al. (Scheme 18) [63]. The protocol is based on the anodic oxidation of α-(phenylthio)acetamides 46 in the presence of Et3N∙3HF. The latter

• °C with olefins bearing a nucleophilic group (Scheme 27) [76]. The cyclization is initiated by nucleophilic attack of the alkene on the acyl iminium species under C,C-bond formation. The resulting cationic intermediate is then trapped by the tethered nucleophile in an exo cyclization step under

A novel 4-aminoantipyrine-Pd(II) complex catalyzes Suzuki–Miyaura cross-coupling reactions of aryl halides

• Claudia A. Contreras-Celedón,
• Darío Mendoza-Rayo,
• José A. Rincón-Medina and
• Luis Chacón-García

Beilstein J. Org. Chem. 2014, 10, 2821–2826, doi:10.3762/bjoc.10.299

• complexes of 4-AAP have shown anti-inflammatory, analgesic, antiviral, antipyretic, antirheumatic and antimicrobial activity [20][21]. Despite the potential biological importance of 4-AAP, the catalytic activity of its transition metal complexes for C–C bond formation have not yet been investigated. Herein

Electrocarboxylation: towards sustainable and efficient synthesis of valuable carboxylic acids

• Roman Matthessen,
• Jan Fransaer,
• Koen Binnemans and
• Dirk E. De Vos

Beilstein J. Org. Chem. 2014, 10, 2484–2500, doi:10.3762/bjoc.10.260

• electrons per CO2 molecule, as shown in Scheme 3 for olefins, with the C–C bond formation highlighted in bold. Industrial organic electrosynthesis The chemical industry is devoting increasing research efforts to the field of organic electrosynthesis [31]. An extended series of electro-organic processes have

Exploration of C–H and N–H-bond functionalization towards 1-(1,2-diarylindol-3-yl)tetrahydroisoquinolines

• Michael Ghobrial,
• Marko D. Mihovilovic and
• Michael Schnürch

Beilstein J. Org. Chem. 2014, 10, 2186–2199, doi:10.3762/bjoc.10.226

• salt [11]. This synthesis has been streamlined by cross dehydrogenative coupling (CDC) – a powerful method for C–C-bond formation via the C–H bonds of a pro-nucleophile and a pro-electrophile [12][13][14]. A landmark contribution published by Li and co-workers reported the successful introduction of

Palladium-catalysed cross-coupling reaction of ultra-stabilised 2-aryl-1,3-dihydro-1H-benzo[d]1,3,2-diazaborole compounds with aryl bromides: A direct protocol for the preparation of unsymmetrical biaryls

• Siphamandla Sithebe and
• Ross S. Robinson

Beilstein J. Org. Chem. 2014, 10, 1107–1113, doi:10.3762/bjoc.10.109

• moisture, their ease with which they are accessible and their non-toxicity, these compounds have, to the best of our knowledge, never been used in any transition metal-catalysed C–C bond formation reaction as coupling partners except for their 2-alkyl/alkenyl-substituted analogues [14]. We are aware of

Aza-Diels–Alder reaction between N-aryl-1-oxo-1H-isoindolium ions and tert-enamides: Steric effects on reaction outcome

• Amitabh Jha,
• Ting-Yi Chou,
• Zainab ALJaroudi,
• Bobby D. Ellis and
• T. Stanley Cameron

Beilstein J. Org. Chem. 2014, 10, 848–857, doi:10.3762/bjoc.10.81

• ]. The reaction of 2-chloroquinoline with 2-formylphenylboronic acid yielded tetracyclic isoindoloquinoline using Suzuki cross-coupling conditions where the C–C bond formation is followed by nucleophilic attack of the pyridine lone pair on the neighbouring aldehyde and proton migration [21]. Several

• can be explained based on steric and electronic factors. In the case derived from 3-chloro-4-fluoroaniline, the C–C bond formation occurred at position 6 of the aromatic ring as it was sterically favoured. In case of the 2-naphthylamine derivative, position 1 of the naphthalene ring is known to be

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

• reactions, including C–C bond formation and addition to unsaturated centers. Because of their importance, α-heterolytic fragmentation reactions of radical anions and cations have been intensively studied from synthetic and mechanistic perspectives [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25

• -peptides via the intermediacy of interconverting zwitterionic biradicals 21 and 22. The biradicals 24 generated by silyl transfer from the zwitterionic biradicals undergo C–C bond formation to form macrocyclic products 23 (Scheme 5). In addition, these studies have shown that the length and nature of the

• , each as a mixture of diastereomers. In these processes, SET from the terminal α-silyl ether donor sites to the excited phthlaimide chromophores produces zwitterionic biradicals 50, which then undergo methanol-assisted desilylation to form biradicals 52, whose cyclization by C–C bond formation produced

Aminofluorination of 2-alkynylanilines: a Au-catalyzed entry to fluorinated indoles

• Antonio Arcadi,
• Emanuela Pietropaolo,
• Antonello Alvino and
• Véronique Michelet

Beilstein J. Org. Chem. 2014, 10, 449–458, doi:10.3762/bjoc.10.42

• [39]. When the same reaction was performed in the presence of [bis(trifluoromethanesulfonyl)imidate](triphenylphosphine)gold(I) catalyst [40] (5 mol %), the formation of the difluorinated 3H-indole 2a was observed although in low overall yield (Table 1, entry 2). No traces of C–C bond formation, a

Recent applications of the divinylcyclopropane–cycloheptadiene rearrangement in organic synthesis

• Sebastian Krüger and
• Tanja Gaich

Beilstein J. Org. Chem. 2014, 10, 163–193, doi:10.3762/bjoc.10.14

• cyclohepta[cd]oxindole core 32 proved the synthetic versatility of a [3,3]-sigmatropic rearrangement for direct C–C-bond formation at the C4 position of the indole nucleus, and thus provides experimental evidence for the biosynthetic proposal. Applications to natural product synthesis Fatty acid metabolites

Continuous-flow Heck synthesis of 4-methoxybiphenyl and methyl 4-methoxycinnamate in supercritical carbon dioxide expanded solvent solutions

• Phei Li Lau,
• Ray W. K. Allen and
• Peter Styring

Beilstein J. Org. Chem. 2013, 9, 2886–2897, doi:10.3762/bjoc.9.325

• recognised as an indispensably simple yet effective method for molecular structure elaboration. The Heck reaction is a useful component of the chemist’s toolkit as it allows carbon chain extension, with the addition of an alkene motif, using catalytic C–C bond formation chemistry. Traditionally, Heck

The myxocoumarins A and B from Stigmatella aurantiaca strain MYX-030

• Tobias A. M. Gulder,
• Snežana Neff,
• Traugott Schüz,
• Tammo Winkler,
• René Gees and
• Bettina Böhlendorf

Beilstein J. Org. Chem. 2013, 9, 2579–2585, doi:10.3762/bjoc.9.293

• bond formation by nucleophilic attack of the aromatic system to the side-chain keto functionality, comparable to the first step of a Pechman condensation reaction. This would already furnish mycoxoumarin A (7, R2 = Me), with myxocoumarin B (9, for R2 = H) being formed after additional loss of H2O. In

• intermediate, putatively phloroglucinol (12) [36]. Nitrophenol 13 likely constitutes a direct biosynthetic precursor of the myxocoumarins. Upon O-acetylation of 13 with the long-chain β-keto acid building block 14, putatively recruited from fatty-acid biosynthesis, the intermediate ester 15 could undergo C–C

Flow synthesis of phenylserine using threonine aldolase immobilized on Eupergit support

• Jagdish D. Tibhe,
• Hui Fu,
• Timothy Noël,
• Qi Wang,
• Jan Meuldijk and
• Volker Hessel

Beilstein J. Org. Chem. 2013, 9, 2168–2179, doi:10.3762/bjoc.9.254

• esterification [27], oxidation and reduction [28], C–C bond formation [29], and polymerization [30]. Recent advancements in the field of enzymatic microreactors include the use of alginate/protamine/silica hybrid capsules with ultrathin membranes [31], monolithic enzyme microreactors [29][32], and biodegradable

Sequential Diels–Alder/[3,3]-sigmatropic rearrangement reactions of β-nitrostyrene with 3-methyl-1,3-pentadiene

• Peter A. Wade,
• Alma Pipic,
• Matthias Zeller and
• Panagiota Tsetsakos

Beilstein J. Org. Chem. 2013, 9, 2137–2146, doi:10.3762/bjoc.9.251

• cycloadducts resulting from C–C bond formation at the end of the conjugated diene system were observed, in keeping with reported results for other conjugated dienes [1][11][12]. However, cycloaddition was relatively indiscriminant at the two double bonds of the diene in this initial experiment. The reaction