Synthesis and Isolation of Homeomorphous Isomers of P-Containing Cryptands

✍ Scribed by Ingmar Bauer; Otto Rademacher; Margit Gruner; Wolf. D. Habicher

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 401 KB
• Volume: 6
• Category: Article
• ISSN: 0947-6539
• DOI: 10.1002/1521-3765(20000818)6:16<3043::aid-chem3043>3.0.co;2-8

✦ Synopsis

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 PCl 3 . 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 C 3 symmetry in the solid state. In the 31 P 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 in-position 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.