Oxidative Photocyclization of Aromatic Imines in Synthesis of aza-PAHs.

0545551 - ÚCHP 2022 CZ eng D - Dizertace
Kos, Martin
Oxidative Photocyclization of Aromatic Imines in Synthesis of aza-PAHs.
Ústav chemických procesů AV ČR, v. v. i.- Vysoká škola chemicko-technologická v Praze. Obhájeno: Praha. 08.09.2021. - Praha, 2021. 225 s.
Institucionální podpora: RVO:67985858
Obor OECD: Organic chemistry

The oxidative photocyclization of aromatic imines was investigated as a potential method for the synthesis of aza-polyaromatic compounds (PAH). The reaction condi-tions were optimized by photocyclization of the model compound N-phenylbenzophenone imine. The regioselectivity of the reaction with variously substi-tuted imines was determined. The high selectivity of 4-nitrophenyl imines was exploited for the synthesis of larger aromatic systems —5-aza[n]helicenes. The series of aza-PAHs containing nitrogen in position 6 were prepared by photocyclization of N-arylbenzophenone imines, where aryl is a polycyclic aromatic substituent (naphthyl, phenanthryl, etc.). The reaction scope was further expanded towards the synthesis of helical ligands. The helicenes bearing one or two 2,2'-bipyridine moieties were prepared by photocyclization of 2-pyridyl imines using Ti(OzPr)4, TEMPO, and quartz filter. NCN tridentate ligands were prepared by photocyclization of corresponding pyridyl-phenyl imines. Finally, the bipy ligands mentioned above were utilized for the prepara-tion for diastereo- and enantiopure mono and bis-ruthenium complexes. The coordina-tion to ruthenium atom generated fused metallic bishelicenic systems with ruthe-na[n]helicenes (n = 4, 5), whose helicity in the solid state are directed by fixed (A/A)- configuration on metal. Spectroelectrochemical UV-VIS and ECD studies of prepared complexes revealed their extensive redox modulated chiroptical properties. Due to the strong reversible changes in ECD spectra upon oxidation of the bis-ruthenium complex, this system was studied as a redox-triggered chiroptical switch.
Trvalý link: http://hdl.handle.net/11104/0322235