Modular synthesis of N-heteroaromatic cations by (2+2+2) cycloaddition
Modulární syntéza N-heteroaromatických kationtů pomocí (2+2+2) cykloadice
dizertační práce (OBHÁJENO)
Zobrazit/ otevřít
Trvalý odkaz
http://hdl.handle.net/20.500.11956/47891Identifikátory
SIS: 117409
Kolekce
- Kvalifikační práce [19614]
Autor
Vedoucí práce
Oponent práce
Kotora, Martin
Potáček, Milan
Fakulta / součást
Přírodovědecká fakulta
Obor
-
Katedra / ústav / klinika
Katedra organické chemie
Datum obhajoby
10. 4. 2012
Nakladatel
Univerzita Karlova, Přírodovědecká fakultaJazyk
Angličtina
Známka
Prospěl/a
5 Abstract N-Heteroaromatic cations represent a family of compounds with diverse application potentials including natural products, DNA probes, fluorescence dyes, herbicides, ionic liquids, organocatalysts, etc. The preparation of these species proceeds mainly through N-alkylation which is used mostly as a last step of the synthetic sequence. Only limited diversity of cationic substrates can be achieved with this manner, hence, searching for other methods leading to novel Nheteroaromatic cations is of great interest. Some examples of transition metal-catalyzed transformations on organic cations have appeared over the last two decades including Suzuki- Miyaura reaction, Sonogashira and Stille coupling, oxidative homocoupling, ring-closing metathesis, etc. Here, the successful construction of new N-heteroaromatic cations by [2+2+2] cycloaddition is presented. A methodology for the synthesis of novel pyridine-type organic monocations was developed using gaseous acetylene as a reaction partner in the cyclization step. Subsequently, the double [2+2+2] cycloaddition was utilized for the preparation of oligo-p-phenylenes with two to seven para connected phenylene units. Furthermore, the intramolecular version of the cyclization step led to two helical and four linear dications which can be considered as extended...
5 Abstract N-Heteroaromatic cations represent a family of compounds with diverse application potentials including natural products, DNA probes, fluorescence dyes, herbicides, ionic liquids, organocatalysts, etc. The preparation of these species proceeds mainly through N-alkylation which is used mostly as a last step of the synthetic sequence. Only limited diversity of cationic substrates can be achieved with this manner, hence, searching for other methods leading to novel Nheteroaromatic cations is of great interest. Some examples of transition metal-catalyzed transformations on organic cations have appeared over the last two decades including Suzuki- Miyaura reaction, Sonogashira and Stille coupling, oxidative homocoupling, ring-closing metathesis, etc. Here, the successful construction of new N-heteroaromatic cations by [2+2+2] cycloaddition is presented. A methodology for the synthesis of novel pyridine-type organic monocations was developed using gaseous acetylene as a reaction partner in the cyclization step. Subsequently, the double [2+2+2] cycloaddition was utilized for the preparation of oligo-p-phenylenes with two to seven para connected phenylene units. Furthermore, the intramolecular version of the cyclization step led to two helical and four linear dications which can be considered as extended...