New library of aminosulfonyl-tagged Hoveyda–Grubbs type complexes: Synthesis, kinetic studies and activity in olefin metathesis transformations

• Etienne Borré,
• Frederic Caijo,
• Christophe Crévisy and
• Marc Mauduit

Beilstein J. Org. Chem. 2010, 6, 1159–1166, doi:10.3762/bjoc.6.132

• concetrations of metal impurities are often present in the final products, limiting industrial applications. Several attempts have been made to reduce the Ru-contamination to <10 ppm, as required by regulatory bodies, for example, by the use of Ru-scavengers, biphasic extraction, silica gel chromatography etc

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

• is a key reaction medium for the reaction of organic thiols with perfluoroalkyl iodides under UV irradiation. However, other solvents have been investigated including alcohols, acetone, acetonitrile, dioxane, THF, DMF, DMSO, HMPA and so on. Polar aprotic solvents emerge as the best. Biphasic

• , CF3I is a poorer electrophile than C3F7I - even under biphasic conditions. 4.1.4. Interaction of thiols with perfluoroalkyl bromides Although brominated perfluoroalkanes are cheaper and more readily available than the corresponding iodides, they react more slowly in thioether forming reactions. In

• interest, although the method can be applied in the case of poorly reactive thiophenols. In general these reactions work well (see section 4.1.6.) in common organic solvents or under biphasic conditions [188][189]. Reactions with perfluoroalkyl bromides are more sluggish. Only compounds with long

Efficient and improved synthesis of Telmisartan

• A. Sanjeev Kumar,
• Samir Ghosh and
• G. N. Mehta

Beilstein J. Org. Chem. 2010, 6, No. 25, doi:10.3762/bjoc.6.25

• ) and 2-(2-bromophenyl)-4,4-dimethyl-2-oxazoline (11) (10.1 g, 0.039 mol) in tetrahydrofuran (50.0 mL), 2 M aqueous sodium carbonate solution (20.0 mL) was added at room temperature. The resulting biphasic solution was degassed with nitrogen gas for 20 min. Tetrakis(triphenylphosphine)palladium(0) (0.25

Continuous flow enantioselective arylation of aldehydes with ArZnEt using triarylboroxins as the ultimate source of aryl groups

• Julien Rolland,
• Xacobe C. Cambeiro,
• Carles Rodríguez-Escrich and
• Miquel A. Pericàs

Beilstein J. Org. Chem. 2009, 5, No. 56, doi:10.3762/bjoc.5.56

• filtration and the biphasic mixture was diluted with dichloromethane and separated. The aqueous layer was extracted with dichloromethane and the combined organic layers were washed with aqueous NaHCO3 solution, dried with Na2SO4, filtered and concentrated under reduced pressure to obtain the product as a

• File 1 for further detail). After 4 h, both reactants were stopped and the system was washed by pumping toluene again for 30 min. The biphasic mixture containing the product was extracted with dichloromethane, washed with aqueous NaHCO3, dried with Na2SO4 and concentrated under reduced pressure. After

Radical carbonylations using a continuous microflow system

• Takahide Fukuyama,
• Md. Taifur Rahman,
• Naoya Kamata and
• Ilhyong Ryu

Beilstein J. Org. Chem. 2009, 5, No. 34, doi:10.3762/bjoc.5.34

• in a controlled manner into the system and was mixed with the toluene solution containing a radical mediator, a radical initiator and a substrate in a T-shaped micromixer (stainless steel, internal diameter: 1000 μm). This biphasic (gas-liquid) mixture was then guided through a stainless steel

Asymmetric reactions in continuous flow

• Xiao Yin Mak,
• Paola Laurino and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2009, 5, No. 19, doi:10.3762/bjoc.5.19

• order to maintain a constant emulsion that was necessary for high yields and enantioselectivities. Pillar-structured channels in the microreactor were designed to facilitate biphasic laminar flow. However, undefined plug flow was observed instead. Various aldehydes were tested using the system; with

A biphasic oxidation of alcohols to aldehydes and ketones using a simplified packed- bed microreactor

• Andrew Bogdan and
• D. Tyler McQuade

Beilstein J. Org. Chem. 2009, 5, No. 17, doi:10.3762/bjoc.5.17

• characterization of a simplified packed-bed microreactor using an immobilized TEMPO catalyst shown to oxidize primary and secondary alcohols via the biphasic Anelli-Montanari protocol. Oxidations occurred in high yields with great stability over time. We observed that plugs of aqueous oxidant and organic alcohol

• , increasing the safety of large-scale oxidations. Furthermore, it was determined that the use of a packed-bed microreactor facilitates efficient mixing of a biphasic system without destroying the solid support, a common problem with stirred systems [4]. Results and Discussion Previously we reported that

• outlet (Figure 2B). The effective mixing was later supported by the high yields and conversions that were achieved for this biphasic reaction. Preliminary reactions were performed using benzyl alcohol as the test substrate in order to establish the optimal flow conditions (Scheme 3). A solution of benzyl

Expedient syntheses of the N-heterocyclic carbene precursor imidazolium salts IPr·HCl, IMes·HCl and IXy·HCl

• Lukas Hintermann

Beilstein J. Org. Chem. 2007, 3, No. 22, doi:10.1186/1860-5397-3-22

• data. Discussion The synthesis of N,N-diarylimidazolium salts according to the Arduengo three component condensation [5] produces strongly colored reaction mixtures, from which the products are obtained as impure raw materials. [5][6][7][8][11] The biphasic aqueous/organic reaction conditions of that