The frontiers of organic chemistry at the Bürgenstock conference.

Highlights from the 46th EUCHEM Conference on stereochemistry, Bürgenstock, Switzerland, May 2011.

Recognizing known faces of possible speakers at the train station is usually how the journey to the outstanding Bürgenstock conference starts, now held in the majestic village of Brunnen, Switzerland (Fig. 1). Tradition dictates that the programme remains a mystery until the beginning of the conference and that speakers can only give one plenary lecture during their life-time. The conference is...

A Non-Diazo Strategy to Cyclopropanation via Oxidatively Generated Gold Carbene: the Benefit of A Conformationally Rigid P,N-Bidentate Ligand.

Potentiometric Determination of Acidity Constants of Some Synthesized Organic Compounds in Organic-Water Media

The acidity constants of some synthesized protonated pyrazolo quinazoline compounds were determined potentiometrically at ionic strength of 0.1 M in DMF: water (60:40 v/v) system at different temperatures (298.15 K to 318.15 K). The pKa values have been found to increase with increasing electron-donating nature of substitutions. Some thermodynamics parameters such as enthalpy (ΔH°), Gibb’s free...

Nickel-Catalyzed Decarboxylative Arylation of Azoles with Perfluoro- and Nitrobenzoates.

This manuscript describes a Ni-catalyzed method for the direct arylation of azoles using benzoates. Perfluorophenyl and 2-nitrobenzoates participate in these reactions to afford the corresponding products in modest to good yields. The efficiency of the arylations with perfluorobenzoates is highly dependent on both the degree and position of fluorine atoms in the benzoates.

Synthetic Strategies Toward the Decalin Motif of Maklamicin and Related Spirotetronates.

Herein we describe a scalable approach to the decalin moiety of maklamicin. Key to the synthesis is an intramolecular Diels-Alder (IMDA) reaction that proceeds via an endo-axial transition state to generate the desired stereochemistry. We explored the diastereoselectivity of the IMDA reaction as a function of both chiral catalysis and acyclic precursor stereochemistry.