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

Bromination of hydrocarbons with CBr₄, initiated by light-emitting diode irradiation

• Yuta Nishina,
• Bunsho Ohtani and
• Kotaro Kikushima

Beilstein J. Org. Chem. 2013, 9, 1663–1667, doi:10.3762/bjoc.9.190

• hydrocarbons proceeds through radical abstraction of hydrogen atoms and trapping with bromide, whereas the bromination reactions of aromatic and unsaturated hydrocarbons are induced by electrophilic addition of bromine and/or a cationic bromide. Combinations of N-bromosuccinimide (NBS) with

Palladium(II)-catalyzed Heck reaction of aryl halides and arylboronic acids with olefins under mild conditions

• Tanveer Mahamadali Shaikh and
• Fung-E Hong

Beilstein J. Org. Chem. 2013, 9, 1578–1588, doi:10.3762/bjoc.9.180

• of arylboronic acids with olefins, which were catalyzed by Pd(OAc)2 and employed N-bromosuccinimide as an additive under ambient conditions. The resulted biaryls have been obtained in moderate to good yields. Keywords: aryl halides; Heck reaction; olefins; palladium-complex; phosphine; Introduction

• sovents, dimethylacetamide (DMAc) and DMF, at 25 °C in the presence of 0.5 equiv of N-bromosuccinimide (NBS). This resulted in the formation of trans-stilbene (3a) in 52% and 40% yield, respectively (Table 3, entries 1 and 2). However, the same reaction under the control conditions (i.e., in the absence

• developed the Heck reaction of arylboronic acids with various alkenes employing N-bromosuccinimide as an additive and catalyzed by Pd(OAc)2, under base- and ligand-free conditions at 25 °C. The yields of the coupled products are moderate to good. Heck reaction of olefins with aryl halides and arylboronic

Synthesis of trifunctional cyclo-β-tripeptide templates

• Frank Stein,
• Tahir Mehmood,
• Tilman Plass,
• Javid H. Zaidi and
• Ulf Diederichsen

Beilstein J. Org. Chem. 2012, 8, 1576–1583, doi:10.3762/bjoc.8.180

• amino acid, the resin was washed with DCM (3 × 3 mL) and the hydrazinobenzoyl linker was oxidized to the acyldiazene by stirring the resin in a solution of N-bromosuccinimide (0.249 g, 1.40 mmol, 2.00 equiv) and pyridine (113 μL, 1.40 mmol, 2.00 equiv) in DCM (3.50 mL) for 7 min. The resin was washed

On the bromination of the dihydroazulene/vinylheptafulvene photo-/thermoswitch

• Virginia Mazzanti,
• Martina Cacciarini,
• Søren L. Broman,
• Christian R. Parker,
• Magnus Schau-Magnussen,
• Andrew D. Bond and
• Mogens B. Nielsen

Beilstein J. Org. Chem. 2012, 8, 958–966, doi:10.3762/bjoc.8.108

• -DHA. Results: Radical bromination on two different VHFs by using N-bromosuccinimide/benzoyl peroxide and light, followed by a ring-closure reaction generated the corresponding 3-bromo-DHAs, as confirmed in one case by X-ray crystallography. According to a 1H NMR spectroscopic study, the ring closure

• preparative scale, which is more tedious when employing a light source. Along this line, we became interested in investigating the possibility of brominating the VHF 2. It was previously shown by Kuroda and Asao [11] that the related VHF 5 underwent bromination by N-bromosuccinimide (NBS) to form the product

• functionalization of DHA [3][5][6][7][8]. HMDS = hexamethyldisilazide. Bromination of VHF [11]. NBS = N-bromosuccinimide. Radical and ionic brominations of VHF. Synthesis of 3,7-dibromo-DHA. Synthesis of a 3,7-dibromoazulene. Regioselective Sonogashira and Suzuki couplings. RuPhos = 2-dicyclohexylphosphino-2',6

Sexithiophenes as efficient luminescence quenchers of quantum dots

• Christopher R. Mason,
• Yang Li,
• Paul O’Brien,
• Neil J. Findlay and
• Peter J. Skabara

Beilstein J. Org. Chem. 2011, 7, 1722–1731, doi:10.3762/bjoc.7.202

• compounds 2a, 2b and 3 were prepared according to our previously reported procedure [14]. 5-(5-Bromothiophen-2-yl)-7-(5-hexylthiophen-2-yl)-2,3-dihydrothieno[3,4-b][1,4]dithiine (4a) To a solution of 3a (0.62 g, 1.47 mmol) in tetrahydrofuran/glacial acetic acid (1:1 v/v, 40 mL), was added N-bromosuccinimide

• ; found, 500.9676. 5-(5-Bromothiophen-2-yl)-7-(5-methylthiophen-2-yl)-2,3-dihydrothieno[3,4-b][1,4]dithiine (4b) Compound 4b was prepared as described for 4a from compound 3b (0.89 g, 2.50 mmol), in tetrahydrofuran/glacial acetic acid (1:1 v/v, 40 mL), and N-bromosuccinimide (0.45 g, 2.50 mmol) to afford

• [3,4-b][1,4]dithiine (6) To a solution of the terthiophene 5 (1.94 g, 5.2 mmol), in tetrahydrofuran/glacial acetic acid (1:1 v/v, 100 mL) was added N-bromosuccinimide (2.04 g, 11.5 mmol) portionwise, in the dark and under rapid stirring. The reaction mixture was stirred for 2 h after which water (150

Structural conditions required for the bridge lithiation and substitution of a basic calix[4]arene

• Conrad Fischer,
• Wilhelm Seichter and
• Edwin Weber

Beilstein J. Org. Chem. 2011, 7, 1602–1608, doi:10.3762/bjoc.7.188

• ], whereas we follow a route involving the formation of a methylene carbanion through lithiation, which by nucleophilic substitution forms the desired bridge-substituted calixarenes [4][5]. While the number of substituted methylene atoms in the first protocol depends clearly on the amount of N

• -bromosuccinimide used, surprisingly only monosubstitution of the chalice is observed by application of the lithiation technique, independent of the amount of n-BuLi. However, twofold substitution on opposite methylene bridges can be achieved by successive application of the latter technique [6]. This may suggest

Total synthesis of (±)-coerulescine and (±)-horsfiline

• Mukund G. Kulkarni,
• Attrimuni P. Dhondge,
• Sanjay W. Chavhan,
• Ajit S. Borhade,
• Yunnus B. Shaikh,
• Deekshaputra R. Birhade,
• Mayur P. Desai and
• Nagorao R. Dhatrak

Beilstein J. Org. Chem. 2010, 6, 876–879, doi:10.3762/bjoc.6.103

• include the following oxidative rearrangements: lead tetraacetate [3], sodium tungstate [11], tert-butyl hypochlorite [12] and N-bromosuccinimide [13]. Other approaches involve the Mannich reaction [14], ring expansion reactions [15][16], 1,3-dipolar [3 + 2] cycloadditions [17][18][19], intramolecular

• 14. Finally, chemoselective reduction of amide 14 with n-BuLi and LAH (under the conditions reported in [27]) gave coerulescine. Compound 1, on treatment with N-bromosuccinimide, gave the 5-bromo derivative, which upon heating with sodium methoxide in the presence of cuprous iodide gave horsfiline in

Conjugated polymers containing diketopyrrolopyrrole units in the main chain

• Bernd Tieke,
• A. Raman Rabindranath,
• Kai Zhang and
• Yu Zhu

Beilstein J. Org. Chem. 2010, 6, 830–845, doi:10.3762/bjoc.6.92

• arylamine. The bromination of aryl units is important for the subsequent palladium-catalyzed coupling reaction. If the aryl unit is thiophene, direct bromination with N-bromosuccinimide is possible to yield monomer M-3 [16]. For the preparation of conjugated DPP-based polymers, palladium-catalyzed