ISSN:
0009-2940
Keywords:
Caesium effect / Chiroptical properties / Circular dichroism / Cyclophanes, multilayered
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Chiral Triple-Layered and Condensed [2.2]Cyclophanes - Synthesis, Structure, Chiroptical PropertiesThe helical title compounds 1-5 are obtained using a simple one-step cyclisation reaction with yields reaching or increasing those obtained by application of organometallic methods in [2.2]phane syntheses. The formation of the triple-layered phanes 1 leads with high selectivity only to the “up-down” isomers with fixed conformation, as shown by X-ray crystallography and by the detection of strong NOEs of the inner hydrogen atoms. For studies on structure-chiroptic relation-ships a systematic sequence of helical [2.2]phanes with larger arene systems is synthesized. Enrichment of enantiomers is achieved by HPLC on (+)-PTrMA; the kinetics of racemisation and the CD spectra are discussed.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19901230129
