title: Synthesis and isolation of homeomorphous isomers of P-containing cryptands
abstract: The novel isomeric phosphite cryptands 2, 3, and 4 could be synthesized by a simple one-pot tripod capping method starting from bisphenol 1 and PCl3. The assembling of five components led to the formation of a macrobicyclic structure, which probably requires an appropriate preorganization of the reactants. In contrast to the NMR spectra of 2, 3, and 4 in solution, the X-ray structures of 2 and 3 reveal that these molecules have no C3 symmetry in the solid state. In the 31P NMR spectra, both in- and out-P atoms have remarkably different chemical shifts due to a distorted geometry around the in-phosphorus. Phosphorus atoms in the inposition have a decreased reactivity. They are, therefore, more slowly oxidized by cumene hydroperoxide than out-P atoms. A stepwise synthesis was developed for phosphite/phosphatecryptands (5, 7, 9, and 15) via the monoprotected bisphenol 11 and the phosphate 14. In addition, the cylindrical macrotricycle 16 was isolated as a mixture of diastereomers from the crude product of this reaction.
authors.affiliation: Institut fur Organische Chemie der Technischen Universitat Dresden, Germany.
authors.initials: I
authors.lastname: Bauer
authors.initials: O
authors.lastname: Rademacher
authors.initials: M
authors.lastname: Gruner
authors.initials: WD
authors.lastname: Habicher