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

• significant in organic synthesis because aryl halides are important synthons for the synthesis of many natural and non-natural products [93][94]. In 2005, Rahman and co-workers reported a pioneering solid state benzylic bromination of diquinoline derivatives via N-bromosuccinimide (NBS) [95]. In 2012, Wang

Chiral phase-transfer catalysis in the asymmetric α-heterofunctionalization of prochiral nucleophiles

• Johannes Schörgenhumer,
• Maximilian Tiffner and
• Mario Waser

Beilstein J. Org. Chem. 2017, 13, 1753–1769, doi:10.3762/bjoc.13.170

• success in terms of enantioselectivity as under no conditions any asymmetric induction could be observed and the same was the case when we tested the use of N-bromosuccinimide under PTC conditions with a variety of different chiral catalysts, thus illustrating rather well some of the major present

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

• heterocycles which were then further treated with NaOCl (≈3.0 equiv) in the same pot at room temperature to afford the desired products which were then purified by column chromatography (Scheme 10). Recently, a facile N-bromosuccinimide (NBS) induced oxidative dehydrogenation of diversely substituted

Synthesis of oligonucleotides on a soluble support

• Harri Lönnberg

Beilstein J. Org. Chem. 2017, 13, 1368–1387, doi:10.3762/bjoc.13.134

• N-bromosuccinimide (NBS) as an activator. The coupling efficiency was high (98%) on using 2.5 equiv of the H-phosphonate synthon and 5 equiv of the activator. After each coupling step, the support was precipitated from Et2O and recrystallized from MeCN/Et2O. The unreacted hydroxy groups were capped

Synthesis of tetrasubstituted pyrazoles containing pyridinyl substituents

• Josef Jansa,
• Ramona Schmidt,
• Ashenafi Damtew Mamuye,
• Laura Castoldi,
• Alexander Roller,
• Vittorio Pace and
• Wolfgang Holzer

Beilstein J. Org. Chem. 2017, 13, 895–902, doi:10.3762/bjoc.13.90

• 2a,b, 3a,b and 4a,b) strongly hints to the involvement of the former into an intramolecular hydrogen bond as indicated in Scheme 3. Cross-coupling reactions Initial attempts to react 4-bromopyrazole 5 – obtained from reaction of 2a with N-bromosuccinimide – with phenylboronic acid (or 3

Molecular-level architectural design using benzothiadiazole-based polymers for photovoltaic applications

• Vinila N. Viswanathan,
• Arun D. Rao,
• Upendra K. Pandey,
• Arul Varman Kesavan and
• Praveen C. Ramamurthy

Beilstein J. Org. Chem. 2017, 13, 863–873, doi:10.3762/bjoc.13.87

• impurities and subsequently brominated using N-bromosuccinimide to produce the desired monomer M1. The synthesis of fluorinated monomer M2 started from 1,2-difluorobenzene. However, the direct bromination of this compound in the 1,4-position is hindered due to the electronegative fluorine substituents. Hence

Nucleophilic and electrophilic cyclization of N-alkyne-substituted pyrrole derivatives: Synthesis of pyrrolopyrazinone, pyrrolotriazinone, and pyrrolooxazinone moieties

• Işıl Yenice,
• Sinan Basceken and
• Metin Balci

Beilstein J. Org. Chem. 2017, 13, 825–834, doi:10.3762/bjoc.13.83

• -nitrobenzene with trimethylsilylacetylene under the Sonogashira coupling conditions followed by hydrolysis of the trimethylsilyl groups with K2CO3 resulted in the formation of 10a and 10b [26][27][28]. Fortunately, terminal alkynes can be easily converted into bromoalkynes with N-bromosuccinimide in the

Novel β-cyclodextrin–eosin conjugates

• Gábor Benkovics,
• Damien Afonso,
• András Darcsi,
• Szabolcs Béni,
• Sabrina Conoci,
• Éva Fenyvesi,
• Lajos Szente,
• Milo Malanga and
• Salvatore Sortino

Beilstein J. Org. Chem. 2017, 13, 543–551, doi:10.3762/bjoc.13.52

• dyes were freshly synthesized starting from fluorescein (Flu, 1). Although the described synthetic procedures for the preparation of eosin dyes commonly use Br2, herein the less hazardous N-bromosuccinimide (NBS) was used as the source of bromine. Thus, eosin Y (2) was prepared in a single step from 1

Efficient access to β-vinylporphyrin derivatives via palladium cross coupling of β-bromoporphyrins with N-tosylhydrazones

• Vinicius R. Campos,
• Ana T. P. C. Gomes,
• Anna C. Cunha,
• Maria da Graça P. M. S. Neves,
• Vitor F. Ferreira and
• José A. S. Cavaleiro

Beilstein J. Org. Chem. 2017, 13, 195–202, doi:10.3762/bjoc.13.22

• substrates were prepared by following literature procedures; the halide partner by controlled bromination of 5,10,15,20-tetraphenylporphyrin (TPP) with N-bromosuccinimide followed by metallation with Zn(AcO)2 [31][32] and the tosylhydrazones 2a–c by reaction of the adequate ketones with tosylhydrazines [33

A new protocol for the synthesis of 4,7,12,15-tetrachloro[2.2]paracyclophane

• Donghui Pan,
• Yanbin Wang and
• Guomin Xiao

Beilstein J. Org. Chem. 2016, 12, 2443–2449, doi:10.3762/bjoc.12.237

• in the bromination process [10][11][12]. In addition, the release of corrosive HBr as a byproduct and the use of organic solvents make this protocol less environmentally friendly [13]. The use of other brominating agents, such as N-bromosuccinimide (NBS) and pyridinium tribromides, also has the

Three-component synthesis of highly functionalized aziridines containing a peptide side chain and their one-step transformation into β-functionalized α-ketoamides

• Lena Huck,
• Juan F. González,
• Elena de la Cuesta and
• J. Carlos Menéndez

Beilstein J. Org. Chem. 2016, 12, 1772–1777, doi:10.3762/bjoc.12.166

• of 1,4-diacetyl-2,5-piperazinedione with aldehydes in the presence of potassium tert-butoxide, followed by deacetylation with hydrazine hydrate (see the Supporting Information File 1 for further details). As shown in Scheme 2, treatment of these materials with N-bromosuccinimide and methanol in

Selective bromochlorination of a homoallylic alcohol for the total synthesis of (−)-anverene

• Frederick J. Seidl and
• Noah Z. Burns

Beilstein J. Org. Chem. 2016, 12, 1361–1365, doi:10.3762/bjoc.12.129

• stirring rates are critical for obtaining optimal results in these heterogeneous bromochlorination reactions of both allylic and homoallylic alcohols. The origin of this stirring dependence is not definitively known, but we suspect that it facilitates the dissolution of N-bromosuccinimide (NBS) into

Unusual traits of cis and trans-2,3-dibromo-1,1-dimethylindane on the way from 1,1-dimethylindene to 2-bromo-, 3-bromo-, and 2,3-dibromo-1,1-dimethylindene

• Rudolf Knorr,
• David S. Stephenson,
• Ernst Lattke,
• Petra Böhrer and
• Jakob Ruhdorfer

Beilstein J. Org. Chem. 2016, 12, 1178–1184, doi:10.3762/bjoc.12.113

• , the hitherto unknown 3,3-dibromo-1,1-dimethylindane (8) might also be prone to such thermal HBr elimination. For comparison, treatment of 1,1-dimethylindane (9) with one equivalent of N-bromosuccinimide (NBS) furnished the expected 3-bromo-1,1-dimethylindane (see Supporting Information File 1), which

• -dimethylindene (2) and their envelope conformations: ax = pseudoaxial, eq = pseudoequatorial; Me = methyl. The ways to 2-bromo- (4), 3-bromo- (3), and 2,3-dibromo-1,1-dimethylindene (7); SuIm = succinimide, NBS = N-bromosuccinimide, Me = methyl. Unsolvated 2-bromo-3-lithio-1,1-dimethylindene (10) precipitated

• of solid KOt-Bu, which consumed 6 within less than 2 hours at rt. Aqueous work-up with Et2O afforded the dibromide 7 (29 mg, 87%) as the only product (hence, no SN2 reaction by KOt-Bu). NEt3 as the base in place of KOt-Bu required 12 days at rt. c) From 1,1-dimethylindane (9): A mixture of N

Synthesis of 2-oxindoles via 'transition-metal-free' intramolecular dehydrogenative coupling (IDC) of sp² C–H and sp³ C–H bonds

• Nivesh Kumar,
• Santanu Ghosh,
• Subhajit Bhunia and
• Alakesh Bisai

Beilstein J. Org. Chem. 2016, 12, 1153–1169, doi:10.3762/bjoc.12.111

• -5,5-dimethylhydantoin), and ICl afforded 2-oxindole 4a in 82%, 16%, and 69%, respectively (Table 1, entries 17–19). Later, we turned our attention to N-halo succinimides as potential oxidants in our methodology [53]. Interestingly, N-iodosuccinimide (NIS), N-bromosuccinimide (NBS), and N

Efficient syntheses of climate relevant isoprene nitrates and (1R,5S)-(−)-myrtenol nitrate

• Sean P. Bew,
• Glyn D. Hiatt-Gipson,
• Graham P. Mills and
• Claire E. Reeves

Beilstein J. Org. Chem. 2016, 12, 1081–1095, doi:10.3762/bjoc.12.103

• . [38] isoprene was reacted with N-bromosuccinimide (NBS, 44) in water at 8–10 °C for 2 h. The reaction afforded a mixture of two allylic bromides and two allylic alcohols in a combined 42% yield, these were tentatively assigned as (E)-45, (Z)-46, rac-47 and rac-48 (route A, Scheme 7). All attempts at

Amino-functionalized (meth)acryl polymers by use of a solvent-polarity sensitive protecting group (Br-t-BOC)

• Helmut Ritter,
• Monir Tabatabai and
• Markus Herrmann

Beilstein J. Org. Chem. 2016, 12, 245–252, doi:10.3762/bjoc.12.26

• heated under reflux. A second 500 mL single-necked flask was equipped with N-bromosuccinimide (NBS, 50 g 0.28 mol) in a mixture of THF/H2O 1:2. To the boiling tert-butanol 5 portions of 5 mL each concentrated sulfuric acid were added dropwise every 15 min. The forming isobutene was bubbled into the NBS

• -CH2-), 1379 (s, νOH). 1-Bromo-2-phenylpropan-2-ol (2b) Into a stirring solution of N-bromosuccinimide (NBS, 32 g, 0.18 mol) in 1/3 THF and 2/3 H2O, α-methylstyrene (10 mL, 0.15 mol) were added. After 2 h of vigorous stirring, THF was evaporated and the aqueous solution was extracted several times with

• solution of N-bromosuccinimide (NBS, 20 g, 0.12 mol) in 1/3 THF and 2/3 H2O, isoprene was added in 3 small portions of 5 mL (0.05 mol) at 0 °C. Stirring was continued for an additional hour. THF was evaporated and the remaining aqueous mixture was extracted several times with diethyl ether. The extract was

A new method for the synthesis of α-aminoalkylidenebisphosphonates and their asymmetric phosphonyl-phosphinyl and phosphonyl-phosphinoyl analogues

• Anna Kuźnik,
• Roman Mazurkiewicz,
• Mirosława Grymel,
• Katarzyna Zielińska,
• Jakub Adamek,
• Ewa Chmielewska,
• Marta Bochno and
• Sonia Kubica

Beilstein J. Org. Chem. 2015, 11, 1418–1424, doi:10.3762/bjoc.11.153

• -acylamino- and dialkoxyphosphonyl groups of 1-aminophosphonates 5, the electrophilicity of these compounds’ α-carbon is displayed only after functionalisation of the α-position with a nucleofuge group, e.g. by α-bromination of 1-aminophosphonates with N-bromosuccinimide [28][38][39][40][41] or by

Electrochemical selenium- and iodonium-initiated cyclisation of hydroxy-functionalised 1,4-dienes

• Philipp Röse,
• Steffen Emge,
• Jun-ichi Yoshida and
• Gerhard Hilt

Beilstein J. Org. Chem. 2015, 11, 174–183, doi:10.3762/bjoc.11.18

• organic trihalide salts [30], N-bromosuccinimide or N-iodosuccinimide and its derivatives [31][32][33][34][35][36], or more specialised reagents such as bis(pyridinium)iodonium(I) tetrafluoroborate [37][38][39]. Next to those, the in situ oxidation of halogenide ions with strong oxidants such as oxone, Pb

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

• ], Py·HBr3 [136], N-bromosuccinimide/pyridine [137], N-iodosuccinimide/K2CO3 [138], and N,N'-diiodo-N,N'-1,2-ethanediylbis(p-toluenesulfonamide) [139]. The oxidative C–O coupling of benzyl alcohols 135 with alkylarenes 136 took place under the action of the Bu4NI/t-BuOOH system in the presence of NaH2PO4

Visible-light-induced bromoetherification of alkenols for the synthesis of β-bromotetrahydrofurans and -tetrahydropyrans

• Run Lin,
• Hongnan Sun,
• Chao Yang,
• Youdong Yang,
• Xinxin Zhao and
• Wujiong Xia

Beilstein J. Org. Chem. 2015, 11, 31–36, doi:10.3762/bjoc.11.5

• alkenes have received considerable attention from chemists, and various approaches have been made in this area. Initially, the classical synthetic pathway for bromocyclization proceeds utilizing bromine [10]. However, molecular bromine is hazardous and difficult to handle. Further research show that N

• -bromosuccinimide (NBS) is an effective alternative for the bromocyclization [11][12][13][14]. Furthermore, Wei Sun and co-workers disclosed an intriguing strategy to access the haloetherfication of alkenols with N-chlorosuccinimide (NCS), leading to the synthesis of β-chlorotetrahydrofurans [15]. Recently we have

Synthesis of an organic-soluble π-conjugated [3]rotaxane via rotation of glucopyranose units in permethylated β-cyclodextrin

• Jun Terao,
• Yohei Konoshima,
• Akitoshi Matono,
• Hiroshi Masai,
• Tetsuaki Fujihara and
• Yasushi Tsuji

Beilstein J. Org. Chem. 2014, 10, 2800–2808, doi:10.3762/bjoc.10.297

• β-CD 14. After the deprotection of the triisopropyl group of 14 and the Glaser dimerization reaction of 15, symmetrical oligothiophene 16 bearing two PM β-CDs was obtained. Treatment of 16 with Na2S and KOH followed by dibromination by N-bromosuccinimide formed dibromo-heptathiophene 17 with two

Visible-light photoredox catalyzed synthesis of pyrroloisoquinolines via organocatalytic oxidation/[3 + 2] cycloaddition/oxidative aromatization reaction cascade with Rose Bengal

• Carlos Vila,
• Jonathan Lau and
• Magnus Rueping

Beilstein J. Org. Chem. 2014, 10, 1233–1238, doi:10.3762/bjoc.10.122

• the selectivity of the reaction to the aromatized product 3aa, N-bromosuccinimide was added to the reaction mixture when the starting materials were completely consumed [29][30][31][73]. In this case the desired product 3aa was obtained in 72% yield (Table 1, entry 1). Other organic dyes such as

Visible-light photoredox catalysis enabled bromination of phenols and alkenes

• Yating Zhao,
• Zhe Li,
• Chao Yang,
• Run Lin and
• Wujiong Xia

Beilstein J. Org. Chem. 2014, 10, 622–627, doi:10.3762/bjoc.10.53

• phenols. The typical approaches include direct electrophilic halogenation by using molecular bromine or N-bromosuccinimide (NBS) [6][7][8], organometallic catalyst-promoted bromination [9][10][11][12], and the oxidative bromination of phenols [13][14][15]. Nevertheless, most of the methods suffer from

Synthesis of five- and six-membered cyclic organic peroxides: Key transformations into peroxide ring-retaining products

• Alexander O. Terent'ev,
• Dmitry A. Borisov,
• Vera A. Vil’ and
• Valery M. Dembitsky

Beilstein J. Org. Chem. 2014, 10, 34–114, doi:10.3762/bjoc.10.6

• -dioxanes 258, 261, and 264, in moderated yields (Scheme 73) [333]. It should be noted that attempts to synthesize related peroxides with N-bromosuccinimide failed [333]. In the studies [334][335] iodine-containing 1,2-dioxanes 266a–c, 268, and 270a,b were synthesized from the corresponding

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