Alexander Schätz

Dependence of enantioselectivity on the ligand/metal ratio in the asymmetric Michael addition of indole to benzylidene malonates: electronic influence of substrates.

Simple bis(oxazoline) ligands, especially azabis(oxazolines), can promote the copper(II)-catalyzed Michael addition of indoles to benzylidene malonates with up to >99 % ee (ee=enantiomeric excess), provided that the ligand/metal ratio is tuned meticulously with particular regard to the electronic properties of the substrate. Despite a common paradigm followed in many asymmetric catalyses, an excess of chiral ligand is not always beneficial. In fact any excess of ligand has to be avoided to reach excellent enantioselectivities when electron-rich benzylidene malonates are used. On the contrary, malonates carrying an electron-withdrawing group require an excess of ligand for an optimum ee value. A correlation of optical yields versus the sigma(I) values of several para substituents shows a sigmoid trajectory. In the presence of an additive, such as triflate, the significance of the ligand/metal ratio vanishes and very good enantioselectivities are achieved at any rate--no matter whether electron-donating or withdrawing substituents are present.

Monomer-on-Monomer (MoM) Mitsunobu Reaction: Facile Purification Utilizing Surface-Initiated Sequestration

A monomer-on-monomer (MoM) Mitsunobu reaction utilizing norbornenyl-tagged (Nb-tagged) reagents is reported, whereby purification was rapidly achieved by employing ring-opening metathesis polymerization, which was initiated by any of three methods utilizing Grubbs catalyst: (i) free catalyst in solution, (ii) surface-initiated catalyst-armed silica, or (iii) surface-initiated catalyst-armed Co/C magnetic nanoparticles.

The links between property and the economy – evidence from the British and German markets

This study supplies empirical evidence on the dynamic interactions between the property markets in Germany and the United Kingdom and their country‐specific macroeconomic environment. Using a VECM framework, the findings contribute to improving the evaluation of the properties’ behaviour by considering a wide range of macroeconomic risk factors. On a long‐term basis, we find remarkable similarities between both examined real estate markets with respect to significance, signs and magnitude of coefficients, despite essential differences in terms of market structure, conditions and performance. This suggests that the fundamental role of property markets in an economy dominates the country‐specific characteristics in the long run. However, the distinctive features of the national property markets, including differences with respect to the financial systems, are primarily relevant during the short‐term adjustment process back to the long‐term equilibrium.

Magnetic Nanobeads as Support for Zinc(II)–Cyclen Complexes: Selective and Reversible Extraction of Riboflavin

Fishing for riboflavin: Highly magnetic polymer-coated Fe/C nanoparticles are used as supports for zinc(II)–cyclen complexes. Quantitative and reversible extraction of riboflavin (vitamin B2) from aqueous solutions and a vitamin dietary supplement is achieved retaining high efficacy for six consecutive cycles. Applying an external magnetic field readily recycles the nanobeads.

Macroeconomic Effects on Emerging Market Sector Indices

This article supplies empirical evidence of the dynamic interactions between international macroeconomic determinants and 10 emerging market sector indices. As so far empirical research has followed the scientific approach of examining each country separately, this article conducts a supranational sector analysis instead. Due to several economic and monetary crises, we find structural breaks in 9 of the 10 sectors. Taking into account the consequential sub-periods, the sensibility of each sector index to macroeconomic influences is detected by the VECM findings which allow conclusions to be drawn about the sector-specific distinctions in the emerging markets. Contrary to theoretical expectations, the majority of the examined sectors benefited from increasing commodity prices during the examination sample. This finding, therefore, affirms that the ongoing catching-up process and the consequential growth in affluence in the emerging countries is largely driven by growing commodity prices and exports.