Ni nanoparticles on RGO as reusable heterogeneous catalyst: effect of Ni particle size and intermediate composite structures in C–S cross-coupling reaction

• Debasish Sengupta,
• Koushik Bhowmik,
• Goutam De and
• Basudeb Basu

Beilstein J. Org. Chem. 2017, 13, 1796–1806, doi:10.3762/bjoc.13.174

• ], and bismuth [13] have been used with specific electron-rich ligands in the C–S coupling reactions. However, these are less common compared to other C–X (X = C, O, N, P) coupling reactions, presumably because sulfur might suppress the catalytic function through its coordinating and adsorptive

Rapid regio- and multi-coupling reactivity of 2,3-dibromobenzofurans with atom-economic triarylbismuths under palladium catalysis

• Maddali L. N. Rao,
• Jalindar B. Talode and
• Venneti N. Murty

Beilstein J. Org. Chem. 2016, 12, 2065–2076, doi:10.3762/bjoc.12.195

• trial reaction was performed with 2,3-dibromobenzofuran (1.1, 3.3 equiv) and tri(p-anisyl)bismuth (1 equiv) with Pd(OAc)2/PPh3, Cs2CO3 (3 equiv) in N-methyl-2-pyrrolidone (NMP) at 90 °C for 1 h as protocol conditions [35]. This protocol furnished the preferential cross-coupling at the more electrophilic

• -dibromobenzofuran (1.1) and 1 equiv of bismuth reagent gave 86% yield (Table 1, entry 10). A few control reactions without base or palladium catalyst showed inferior or no cross-coupling reactivity (Table 1, entries 11 and 12). This investigation results that the desired regio-selective cross-coupling reactivity

• excellent general reactivity (Table 2, entries 1–12). It was highly satisfying to note that the corresponding products 2.1–2.12 were obtained in 79–95% yields. It prompted us to extend our study to other functionalized 2,3-dibromobenzofuran substrates. For example, a few bismuth couplings carried out with

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

• ] (Scheme 2, path B); Cohen et al. reported the application of bismuth(III) nitrate for isoprene epoxide ring-opening/trapping with nitrate [19] (Scheme 2, path C). The 2010 report by Shepson et al. (path A) exploited chemistry originally described by Nichols et al. who, employing nitric acid as a

• application to the synthesis of high-boiling diols is more difficult due to their low-vapour pressures. Recently Cohen et al. synthesised mixtures of IPNs via the reaction of (±)-isoprene epoxide with pre-ground bismuth(III) nitrate [19]. Using a preliminary ’flash’ purification (silica gel) afforded an

Regioselective synthesis of chiral dimethyl-bis(ethylenedithio)tetrathiafulvalene sulfones

• Flavia Pop and
• Narcis Avarvari

Beilstein J. Org. Chem. 2015, 11, 1105–1111, doi:10.3762/bjoc.11.124

• previously observed only in bismuth wires and carbon nanotubes [13]. Another interesting research area is the redox modulation of the chiroptical properties described in derivatives such as TTF-allenes [14], TTF-helicenes [15], or TTF-paracyclophanes [16]. Thus, to address the different opportunities offered

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

• ) reaction [99]. This allows the direct synthesis of flavone-3-ols, although the yields vary depending on the substrates used. Simpson et al. [100] improved the reaction conditions of AFO in order to synthesize the flavonol rhamnocitrin by using bismuth carbonate and acetic acid. This increased the yields to

Cuevaenes C–E: Three new triene carboxylic derivatives from Streptomyces sp. LZ35ΔgdmAI

• Jing-Jing Deng,
• Chun-Hua Lu,
• Yao-Yao Li,
• Shan-Ren Li and
• Yue-Mao Shen

Beilstein J. Org. Chem. 2014, 10, 858–862, doi:10.3762/bjoc.10.82

• was added to 5 mL of 1.7% (w/v) bismuth nitrate solution in 20% (v/v) acetic acid, and the mixture was diluted to 100 mL with 10% (w/v) sulfuric acid). Material. Strain LZ35 was isolated from the intertidal soil collected at Jimei, Xiamen, China. It was identified as a Streptomyces species according

Photoinduced synthesis of unsymmetrical diaryl selenides from triarylbismuthines and diaryl diselenides

• Yohsuke Kobiki,
• Shin-ichi Kawaguchi,
• Takashi Ohe and
• Akiya Ogawa

Beilstein J. Org. Chem. 2013, 9, 1141–1147, doi:10.3762/bjoc.9.127

• , a bismuth mirror was observed and the yield of 3aa decreased. We assume that the reaction proceeds with bismuth residue getting oxidized. A plausible reaction pathway for the photoinduced reaction of diaryl diselenide with triarylbismuthine is shown in Scheme 3. First, an aryl radical is generated

• this solid is a bismuth residue, which can consist of bismuth oxides and/or bismuth selenides. Moreover, it may form biaryls (Ar–Ar) as byproducts, but no biaryl was observed after the reaction. Conclusion We have found that the photoinduced reaction of diaryl diselenides with triarylbismuthines

Efficient oxidation of oleanolic acid derivatives using magnesium bis(monoperoxyphthalate) hexahydrate (MMPP): A convenient 2-step procedure towards 12-oxo-28-carboxylic acid derivatives

• Jorge A. R. Salvador,
• Vânia M. Moreira,
• Rui M. A. Pinto,
• Ana S. Leal and
• José A. Paixão

Beilstein J. Org. Chem. 2012, 8, 164–169, doi:10.3762/bjoc.8.17

• : bismuth(III) triflate; δ-hydroxy-γ-lactones; MMPP; oleanolic acid; triterpenoid; Findings The molecular diversity that arises from research into natural products represents a valuable tool for driving drug discovery and development [1][2]. In this context, pentacyclic triterpenoids are currently regarded

• -lactones can be efficiently converted into the corresponding 12-oxo-28-carboxylic acid derivatives by bismuth(III) triflate catalysis [18]. This new approach not only avoids an inconvenient multistep synthesis by means of a protection/deprotection strategy [19][20] but also results in chemical modification

• structure of compound 4 was obtained by single-crystal X-ray crystallography, and the ORTEP diagram with the corresponding atomic numbering scheme is depicted in Figure 1. In the past few years, bismuth(III) salts have emerged as convenient reagents for the development of new chemical processes under more

Gold-catalyzed propargylic substitutions: Scope and synthetic developments

• Olivier Debleds,
• Eric Gayon,
• Emmanuel Vrancken and
• Jean-Marc Campagne

Beilstein J. Org. Chem. 2011, 7, 866–877, doi:10.3762/bjoc.7.99

• Friedel–Crafts type reactions with benzylic and propargylic alcohols. Shortly after, Sanz and Zhan discovered, that these reactions could also be carried out under Brønsted acid and FeCl3 catalysis, respectively [26][27][28][29]. Later, the use of copper, indium, bismuth, scandium, ytterbium

Reciprocal polyhedra and the Euler relationship: cage hydrocarbons, C_nH_n and closo-boranes [B_xH_x]²⁻

• Michael J. McGlinchey and
• Henning Hopf

Beilstein J. Org. Chem. 2011, 7, 222–233, doi:10.3762/bjoc.7.30

• polycycloalkanes have been constructed from other elemental species: Clusters containing lithium, transition metals, silicon, phosphorus, arsenic, bismuth, lead, etc. have been characterized [61][62][63][64], and their architectures continue to delight us. The existence of molecules of such exquisite symmetry

SbCl₃-catalyzed one-pot synthesis of 4,4′-diaminotriarylmethanes under solvent-free conditions: Synthesis, characterization, and DFT studies

• Ghasem Rezanejade Bardajee

Beilstein J. Org. Chem. 2011, 7, 135–144, doi:10.3762/bjoc.7.19

• acids such as zinc chloride, zeolites, montmorillonite K-10, and polymer-supported sulfonic acid (NKC-9) [35][36][37][38][39][40]. Microwave-assisted synthesis of DTMs in the presence of aniline hydrochloride has also been described [41]. Recently, bismuth(III) nitrate and zirconium(IV) dichloride oxide

Formation of epoxide-amine oligo-adducts as OH-functionalized initiators for the ring-opening polymerization of ε-caprolactone

• Julia Theis and
• Helmut Ritter

Beilstein J. Org. Chem. 2010, 6, 938–944, doi:10.3762/bjoc.6.105

• by bismuth(III) trifluoromethanesulfonate, which is known as effective catalyst for ROP [27] (Scheme 2). The dilution of the hydroxy groups in the obtained product 6 was proven by IR spectroscopy by the nearly complete disappearance of the OH-related absorption band at 3370 cm−1. Furthermore, the

• bismuth(III) trifluoromethanesulfonate (Aldrich) were used without further purification. Diglycidyl ether of bisphenol A (Sigma) was recrystallized from an acetone-methanol mixture (20:80, v/v); mp 44 °C [28]. ε-CL was purchased from Aldrich, dried over calcium hydride, distilled under reduced pressure

• (7’), 46.78 (6’’), 43.75 (6’), 40.69 (13), 30.00 (14), 17.75 (A). Synthesis of graft copolymer 6 57.9 mg (0.125 mmol) of the epoxide-amine addition product 4 and 1.142 g (10 mmol) of ε-CL (5) were mixed with 0.05 mol % of the catalyst bismuth(III) trifluoromethanesulfonate in a 10 mL vial sealed

A review of new developments in the Friedel–Crafts alkylation – From green chemistry to asymmetric catalysis

• Magnus Rueping and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2010, 6, No. 6, doi:10.3762/bjoc.6.6

• warfarin-class that is widely used in thrombosis prophylaxis. Simply starting from 4-hydroxycoumarin (18) and 1-phenylpropan-1-ol (19), phenprocoumon (20) was obtained in 94% yield (Scheme 9) [27]. As a suitable alternative to transition metals, bismuth salts have emerged as cheap, non-toxic, and readily

• available catalysts with Lewis acidic properties. Given that certain bismuth salts are compatible with air and moisture, the Rueping group decided to examine the bismuth-catalysed arylation and alkylation of benzyl alcohols. With small amounts of Bi(OTf)3 (0.5 mol%) they were able to benzylate arenes

• catalyst [117][118]. While bismuth-catalyzed arylation of benzyl alcohols proceeded only at temperatures between 55 and 100 °C, the reaction of p-methoxybenzyl acetates 113 with silyl enol ethers 114 took place even at ambient temperatures to give the desired products 115 (Scheme 42) [118]. Again different

The first direct synthesis of β-unsubstituted meso- decamethylcalix[5]pyrrole

• Luis Chacón-García,
• Lizbeth Chávez,
• Denisse R. Cacho and
• Josue Altamirano-Hernández

Beilstein J. Org. Chem. 2009, 5, No. 2, doi:10.3762/bjoc.5.2

• The first direct synthesis of β-unsubstituted meso-decamethylcalix[5]pyrrole from pyrrole and acetone, with moderate yield, is described. The results showed that a bismuth salt was necessary to obtain calix[5]pyrrole, with the best results obtained using Bi(NO3)3. Keywords: bismuth; calix[5]pyrrole

• catalyzed by a Brønsted-Lowry acid such as HCl or methanesulfonic acid, or a Lewis acid such as zeolites with aluminium or cobalt, BF3 or a bismuth salt [2][3][4][5]. The synthesis of calix[n]pyrroles where n > 4 has been reported for n = 5 or 6. The latter compounds have been synthesized via two routes: a

• ketone is that the five heterocycle system is unstable: it opens and loses a pyrrole-isopropyl fragment to give the calix[4]pyrrole [8][10]. In a recent report we described the synthesis of calix[4]pyrroles via the direct condensation of pyrrole with a series of ketones in the presence of a bismuth salt