Miocene squat lobsters (Decapoda, Anomura, Galatheoidea) of the Central Paratethys - a review, with description of a new species of Munidopsis.

All squat lobsters of the families Galatheidae, Munididae and Munidopsidae from the Miocene of the Central Paratethys are reviewed taxonomically. Based on additional observations emended diagnoses are provided for Agononida cerovensis and Galathea weinfurteri, from the Lower and Middle Miocene, respectively. Munidopsis is represented by two species in the study area; additional data for M. lieskovensis from the Lower Miocene of Slovakia are presented and a new species, M. palmuelleri, from the Middle Miocene of Slovenia is erected. Implications for palaeoenvironmental reconstructions are briefly discussed for each taxon.

Metal complexes of a biconcave porphyrin with D4-structure--versatile chiral shift agents.

Representative metal complexes of a biconcave D4-symmetric porphyrin were synthesised by metalion insertion into the porphyrin ligand 1. The NMR spectra suggested D4-symmetry for the ZnII and dioxo-RuVI complexes of 1 and C4-symmetry for the unsymmetrically ligated RuII and RhIII complexes. Metal complexes of 1 proved to be versatile chiral 1H NMR shift agents for a broad spectrum of organic amines, alcohols, carboxylic acids, esters, nitriles and nonpolar fullerene derivatives. A practical analysis of chiral substrates with 1 covers enantiomeric excesses beyond 99%. An X-ray structure of (1:1)-cocrystals of an achiral, biconcave CoII porphyrinate and C60 provided the first detailed insights into the structure of such a biconcave metallo-porphyrinate. It also showed remarkable packing of the carbon sphere against the main concave units of the porphyrin and gave clues about the relevant interactions between biconcave porphyrins and fullerenes.

A highly enantiopure biconcave porphyrin with effective D4-structure

A first representative of an effectively D4-symmetric biconcave porphyrin (1) was prepared from a tetramerizing condensation of a C2-symmetric pyrrole (2). The chiral pyrrole 2 was synthesized in a six-step reaction sequence starting from the C2h-symmetric 2,6-di-tert-butylanthracene. The relevant stereochemistry was introduced in a highly diastereo-discriminating Diels-Alder reaction with fumaric acid di(-)menthyl ester, catalyzed by aluminum chloride. X-ray analyses of two of the dimenthyl esters prepared unambiguously secured their tentatively assigned absolute configuration and that of the pyrrole 2 (as the S,S isomer). The enantiomeric purity of the pyrrole 2 was determined as 99% ee, using the Co11 complex of the porphyrin 1 as a chiral shift reagent. The pyrrole 2 lent itself to a stereochemically nearly uniform preparation of the chiral, biconcave porphyrin 1. Applying Horeau's principle, 1 was calculated to be present in an enantiomeric excess of about 10(9):1. The validity of the statistical considerations relevant for this estimate were verified by examination of the results from preparative tetramerization experiments in which the enantiomeric purity of the pyrrole 2 was deliberately lowered.