Construction of the Bicyclic Carbon Framework of Euphosalicin.

Our studies toward the total synthesis of the natural product euphosalicin () are presented. Different approaches targeting key intermediates are described, the synthesis of which includes findings on asymmetric dihydroxylations and ring-closing enyne metatheses (RCEYM). Their connection allowed the isolation of highly advanced precursors for studies on macrocyclizations.

! Europium-catalyzed [3,3] and [5,5] rearrangements of aryl-pentadienyl ethers.

A general protocol for the europium-catalyzed rearrangement of aryl-pentadienyl-ethers is described. The mode of rearrangement and product formation in this reaction was solely determined by the aryl substituent to the phenol. If the -position is occupied by a substituent, the substrate undergoes a [3,3] rearrangement to the -position to form a prochiral branched diene.

Efforts toward the Total Synthesis of Elisabethin A.

We describe our efforts toward the total synthesis of the natural product elisabethin A. The first route was guided by the proposed biosynthesis, assembling the 6,6-ring system before forming the five-membered ring including the quaternary carbon. The second approach includes a high yielding cyclization under Mitsunobu conditions as a key step.

Surface-active ionic liquids in micellar catalysis: impact of anion selection on reaction rates in nucleophilic substitutions.

A series of surface-active ionic liquids based on the 1-dodecyl-3-methylimidazolium cation and different anions such as halides and alkylsulfates was synthesized. The aggregation behavior of these ionic liquids in water was characterized by surface tension, conductivity measurements and UV-Vis spectroscopy in order to determine the critical micelle concentration (CMC) and to provide aggregation parameters. The determination of surface activity and aggregation properties of amphiphilic ionic liquids was accompanied by SAXS studies on selected surface-active ionic liquids.

Coordinating Chiral Ionic Liquids: Design, Synthesis, and Application in Asymmetric Transfer Hydrogenation under Aqueous Conditions.

Hydrophilic coordinating chiral ionic liquids with an amino alcohol substructure were developed and efficiently applied to the asymmetric reduction of ketones. Their careful design and adaptability to the desired reaction conditions allow for these chiral ionic liquids to be used as the sole source of chirality in a ruthenium-catalyzed transfer hydrogenation reaction of aromatic ketones. When used in this reaction system, these chiral ionic liquids afforded excellent yields and high enantioselectivities.

Direct extraction of genomic DNA from maize with aqueous ionic liquid buffer systems for applications in genetically modified organisms analysis.

To date, the extraction of genomic DNA is considered a bottleneck in the process of genetically modified organisms (GMOs) detection. Conventional DNA isolation methods are associated with long extraction times and multiple pipetting and centrifugation steps, which makes the entire procedure not only tedious and complicated but also prone to sample cross-contamination. In recent times, ionic liquids have emerged as innovative solvents for biomass processing, due to their outstanding properties for dissolution of biomass and biopolymers.

Coordinating chiral ionic liquids.

A practical synthesis of novel coordinating chiral ionic liquids with an amino alcohol structural motif was developed starting from commercially available amino alcohols. These basic chiral ionic liquids could be successfully applied as catalysts in the asymmetric alkylation of aldehydes and gave high enantioselectivities of up to 91% ee.

Synthesis and analytics of 2,2,3,4,4-d5-19-nor-5alpha-androsterone--an internal standard in doping analysis.

A short and efficient synthesis of pentadeuterated 2,2,3,4,4-d5-19-nor-5alpha-androsterone 7 starting from 19-norandrost-4-ene-3,17-dione 1 by a d1-L-Selectride mediated stereo- and regioselective reduction of the 3-keto group is presented. The use of compound 7 as internal standard for the detection of anabolic steroids via mass spectrometric techniques such as gas chromatography-mass spectrometry (GC-MS) is discussed.

An iron-containing ionic liquid as recyclable catalyst for aryl grignard cross-coupling of alkyl halides.

[reaction: see text] The ionic liquid butylmethylimidazolium tetrachloroferrate (bmim-FeCl(4)) was found to be a very effective and completely air stable catalyst for the biphasic Grignard cross-coupling with primary and secondary alkyl halides bearing beta-hydrogens. After simply decanting the product in the ethereal layer, the ionic liquid catalyst was successfully recycled four times.