Bromine–lithium exchange: An efficient tool in the modular construction of biaryl ligands

• Laurence Bonnafoux,
• Frédéric R. Leroux and
• Françoise Colobert

Beilstein J. Org. Chem. 2011, 7, 1278–1287, doi:10.3762/bjoc.7.148

• routes to synthetically challenging aryl halide precursors have been devised. A. Alexakis et al. recently achieved a significant breakthrough. They succeeded in the desymmetrization of prochiral polybrominated [32][51] compounds by an asymmetric bromine–lithium exchange in the presence of a

Scaling up of continuous-flow, microwave-assisted, organic reactions by varying the size of Pd-functionalized catalytic monoliths

• Ping He,
• Stephen J. Haswell,
• Paul D. I. Fletcher,
• Stephen M. Kelly and
• Andrew Mansfield

Beilstein J. Org. Chem. 2011, 7, 1150–1157, doi:10.3762/bjoc.7.133

• monolith catalyst. A reactant solution containing an aryl halide (0.1 M), arylboronic acid (0.12 M), K2CO3 (0.3 M) in DMF/H2O (3:1) solvent was pumped through the reactor with an HPLC pump, and a backpressure valve (45–75 psi) was used to minimize the formation of gas bubbles (see Supporting Information

Homocoupling of aryl halides in flow: Space integration of lithiation and FeCl₃ promoted homocoupling

• Aiichiro Nagaki,
• Yuki Uesugi,
• Yutaka Tomida and
• Jun-ichi Yoshida

Beilstein J. Org. Chem. 2011, 7, 1064–1069, doi:10.3762/bjoc.7.122

• functional groups, can be used for this transformation in the integrated flow microreactor system. Hence, the method greatly enhances the synthetic utility of aryllithium compounds and adds a new dimension to the chemistry of coupling reactions. Flow microreactor system for halogen–lithium exchange of aryl

• halide followed by reaction with methanol. T-shaped micromixer: M1 (inner diameter: 250 μm), and M2 (inner diameter: 500 μm), microtube reactor: R1 and R2 ( = 1000 μm, length = 50 cm), a solution of aryl halides: 0.10 M in THF (6.0 mL/min), a solution of lithium reagent: 0.40 M or 0.42 M in hexane (n

A rapid and efficient synthetic route to terminal arylacetylenes by tetrabutylammonium hydroxide- and methanol-catalyzed cleavage of 4-aryl-2-methyl-3-butyn-2-ols

• Jie Li and
• Pengcheng Huang

Beilstein J. Org. Chem. 2011, 7, 426–431, doi:10.3762/bjoc.7.55

• have been widely used in the preparation of photoelectric devices such as organic light-emitting diodes (OLEDs) [1][2][3][4], field-effect transistors (OFETs) [5][6], and organic photovoltaic cells (OPVCs) [7][8][9]. The palladium-catalyzed Sonogashira cross-coupling of an aryl halide with a mono

Air-stable, recyclable, and time-efficient diphenylphosphinite cellulose-supported palladium nanoparticles as a catalyst for Suzuki–Miyaura reactions

• Qingwei Du and
• Yiqun Li

Beilstein J. Org. Chem. 2011, 7, 378–385, doi:10.3762/bjoc.7.48

• –Pd0). General procedure for the Suzuki–Miyaura cross-coupling reaction In a typical experiment, the Cell–OPPh2–Pd0 catalyst (0.005 mmol of Pd) was added to a mixture of aryl halide (1.0 mmol), arylboronic acid (1.2 mmol), and K2CO3 (2.0 mmol) in 95% ethanol (5 cm3), and the reaction mixture was

Studies on Pd/NiFe₂O₄ catalyzed ligand-free Suzuki reaction in aqueous phase: synthesis of biaryls, terphenyls and polyaryls

• Sanjay R. Borhade and
• Suresh B. Waghmode

Beilstein J. Org. Chem. 2011, 7, 310–319, doi:10.3762/bjoc.7.41

• reflux condenser, were added the aryl halide (1 mmol), boronic acid (1.25 mmol), Na2CO3 (2 mmol), and Pd/NiFe2O4 (0.1 mol %) in 4 mL DMF/H2O (1:1), and the reaction mixture heated at the appropriate temperature and duration. The reaction was monitored by gas chromatography. After the reaction was

Palladium- and copper-mediated N-aryl bond formation reactions for the synthesis of biological active compounds

• Carolin Fischer and
• Burkhard Koenig

Beilstein J. Org. Chem. 2011, 7, 59–74, doi:10.3762/bjoc.7.10

• -labile functional groups are present. Electron-neutral and electron-poor aryl bromides are suitable substrates [17], and ortho-substituents on the aryl halide are tolerated. In contrast, electron-rich aryl bromides give only poor results. Recently, the modular synthesis of indoles by a palladium

• structure–activity relationship [49]. Federsel et al. used a piperazine derivative 6 and an aryl halide 5 for the preparation of a CNS-active substituted chiral aminotetralin 7 (Scheme 2) [50]. The 5-HT1B receptor antagonist 8 was developed for the treatment of certain neuronal disorders. Different

Aromatic and heterocyclic perfluoroalkyl sulfides. Methods of preparation

• Vladimir N. Boiko

Beilstein J. Org. Chem. 2010, 6, 880–921, doi:10.3762/bjoc.6.88

• ]. Presumably, coordination of the complex anionic nucleophile K+[Ag(SCF3)I]− with aryl halide accelerates the reaction. Trifluoromethylthiocopper and trifluoromethylthiomercury also participate in analogous reactions, CuSCF3 is less active than AgSCF3 whilst Hg(SCF3)2 displays increased reactivity as indicated

C-Arylation reactions catalyzed by CuO-nanoparticles under ligand free conditions

• Mazaahir Kidwai,
• Saurav Bhardwaj and
• Roona Poddar

Beilstein J. Org. Chem. 2010, 6, No. 35, doi:10.3762/bjoc.6.35

• and iodobenzene was treated with acetylacetone under similar reaction conditions, the chlorobenzene was largely unreactive. This shows that the reaction is highly selective towards the halogen present in the aryl halide (Scheme 2). To study the scope of this procedure, acetylacetone was reacted with

Solvent-free and time-efficient Suzuki–Miyaura reaction in a ball mill: the solid reagent system KF–Al₂O₃ under inspection

• Franziska Bernhardt,
• Ronald Trotzki,
• Tony Szuppa,
• Achim Stolle and
• Bernd Ondruschka

Beilstein J. Org. Chem. 2010, 6, No. 7, doi:10.3762/bjoc.6.7

• the reaction [29][70]. From the data in Figure 5, another interesting fact can be recognized: the strength of the influence of residual water seems to be also dependent on the polarity of the applied aryl bromide. The higher the polarity of the aryl halide, the higher is the influence of the residual

From discovery to production: Scale- out of continuous flow meso reactors

• Peter Styring and
• Ana I. R. Parracho

Beilstein J. Org. Chem. 2009, 5, No. 29, doi:10.3762/bjoc.5.29

• vessel 1. The reaction studied was the Kumada reaction [11][12] which involves the coupling of an aryl halide and a Grignard reagent, in this case 4-bromoanisole and phenylmagnesium chloride, to produce 4-methoxybiphenyl (4-MeOBP, R-Ar). It was also observed that anisole, 4′,4-dimethoxybyphenyl (4,4′-di

Reduction of arenediazonium salts by tetrakis(dimethylamino)ethylene (TDAE): Efficient formation of products derived from aryl radicals

• Mohan Mahesh,
• John A. Murphy,
• Franck LeStrat and
• Hans Peter Wessel

Beilstein J. Org. Chem. 2009, 5, No. 1, doi:10.3762/bjoc.5.1

• anion, a substrate other than an aryl halide would need to be used. As the one-electron reduction of an arenediazonium salt occurs [60] at much more positive potentials (Ep 0.16 V vs SCE) than for aryl iodides [61] (Ep −2.2 V vs SCE), this gives a much better chance to observe a second reductive peak in

A convenient catalyst system for microwave accelerated cross- coupling of a range of aryl boronic acids with aryl chlorides

• Matthew L. Clarke,
• Marcia B. France,
• Jose A. Fuentes,
• Edward J. Milton and
• Geoffrey J. Roff

Beilstein J. Org. Chem. 2007, 3, No. 18, doi:10.1186/1860-5397-3-18

• preferred procedure used 0.5 mmol of aryl halide and 0.75 mmol of boronic acid in 4–5 ml of solvent. In contrast to the mono-fluorinated phenyl boronic acids, 2,3,6-trifluorophenyl boronic acid failed to give appreciable amounts of product, even with an aryl bromide substrate (Table 1, Entries 15 and 16