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On Azahelicenes: Synthesis, Resolution, Properties and Applications
Míšek, Jiří ; Starý, Ivo (advisor) ; Kroutil, Jiří (referee) ; Macháček, Vladimír (referee) ; Závada, Jiří (referee)
1 Abstract A novel and modular approach to azahelicenes has been developed. Using 12+2+2) cyclotrimerisation of appropriate triyne as a key step, azahelicenes 83, 84 and 85 have been prepared (Scheme 1). &83 84 Scheme 1. Aza[6]he|icenes 84 and 85 have shown to be sufÍicienl|y conÍigurationa||y stable and have been resolve inlo individual enantiomers by the diastereoisomeric sa|t crysta|isation and chira| HPLC. This a||owed to determine exact Va|ues oÍ racemisation barriers Íorboth aza[6]he|icenes 84 and 85. In general' both hexacyclic derivatives 84 and 85 are stable enough to be used in asymmetric transÍormations or chira| sensing. The abi|ity oÍ aza[6]he|icenes 84 and 85 to serve as chira| ligands íortransition meta|s has been proven by the preparation and X. ray analysis ol corresponding si|ver comp|exes. lnteresting chira| selÍ.recogniton properties oÍaza[6]he|icenes 84 in gas phase have been described using mass spectrometry techniques. |n order to comp|ement inÍormation about azahelicenes basicilies, gas phase proton afÍinities oÍ derivatives 84 and 85 and so|ution phase dissociation constants oÍ azahe|icenes 83. 84 and 85 have been determined. Eventua||y, the Íirst uti|ization oÍ azahe|icene in asymmetric catalysis has been demonstrated by the successÍu| use oÍ optical|y pure aza[6]he|icene...
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