Combinatorial Chemistry for Ligand Development in Catalysis: Synthesis and Catalysis Screening of Peptidosulfonamide Tweezers on the Solid Phase

On the basis of a pyrrolidine tweezer 1, a library of peptidosulfonamide tweezers (15a-e, 16a-e) was synthesized on the solid phase. This library was screened in a simultaneous substrate screening procedure for the ability to enantioselectively catalyze the Ti(O-i-Pr)(4)-mediated addition of diethylzinc to aldehydes. One of the best solid-phase tweezer catalyst (i.e., 16d, giving an ee of 32% in solid-phase catalysis) was resynthesized in solution (compounds 20 and 21). The now homogeneous solution-phase catalysis showed even better enantioselectivity (i.e., up to 66%).     

Selbstorganisation von Molekülen über kovalente Bindungen: Selektive Tetramerisierung eines p-Chinodimethans

Self-Organization of Molecules by Covalent Bonds: Selective Tetramerization of a p -Quinodimethane A simple and efficient synthesis of paracyclophane derivatives based on self-organization of a quinodimethane is described. Treatment of dibromides 5a – d with mercury afforded in high yield the macrocyclic compounds 6a – d . Interestingly, these compounds change the color on grinding and heating, from colorless to violet. The structure of 6a – d was determined by spectroscopic analyses. Single-crystal structure analysis of 6b and 6c confirmed the proposed structure.     

Gamma-ray spectroscopy with relativistic exotic heavy-ions

Feasibility of gamma-ray spectroscopy at relativistic energies with exotic heavy-ions and new generation of germanium detectors (segmented Clover) is discussed. An experiment with such detector array and radioactive is discussed.     

Zur Theorie der Gammafunction

Ohne Zusammenfassung Vergl. meine Abhandlung:Om en ny klass af transcendenta functioner, hvilka ?ro n?ra besl?gtade med gammafunktionen, Acta soc. scient. Fennic?, Tom. XIV, XV; 1885, 1886.