Synthesis and Photophysical Properties of Polycarbo-Substituted Quinazolines Derived from the 2-Aryl-4-chloro-6-iodoquinazolines.
The reactivity of the 2-aryl-4-chloro-6-iodoquinazolines towards palladium catalyzed sequential (Sonogashira/Suzuki-Miyaura) and one-pot two-step cross-coupling (bis-Sonogashira, and successive Sonogashira/Stille) reactions to afford novel unsymmetrical polycarbo-substituted quinazolines has been evaluated. In contrast to the chloro-bromo substituted quinazolines in which selectivity has been previously found to generally favor substitution at the more activated C(4)-Cl bond over the weaker Csp(2)-Br bond, substitution in the case of the chloro-iodo derivatives favors cross-coupling through the intrinsically more reactive Csp(2)-I bond. The electronic absorption and emission properties of the prepared 2,3-diaryl-6-(phenylethynyl)quinazolines were studied in solvents of different polarity (dichloromethane, toluene, DMF, methanol) and CH2Cl2-TFA mixture using UV-Vis and emission spectroscopic techniques complemented with density functional theory method to establish the effect of substituents on intramolecular charge transfer properties.
Department of Chemistry, College of Science, Engineering and Technology, University of South Africa, P.O. Box 392, Pretoria 0003, South Africa. mphahmj@unisa.ac.za.
Malose Jack
MJ
Mphahlele
Department of Chemistry, College of Science, Engineering and Technology, University of South Africa, P.O. Box 392, Pretoria 0003, South Africa. tkademph@unisa.ac.za.
Hugues Kamdem
HK
Paumo
Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit 80837, Mauritius. lyd.rhyman@gmail.com.
Lydia
L
Rhyman
Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit 80837, Mauritius. ramchemi@intnet.mu.
Ponnadurai
P
Ramasami
D002384:Catalysis; D006847:Hydrocarbons, Iodinated / Q000138:chemical synthesis / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry; D055668:Photochemical Processes; D011799:Quinazolines / Q000138:chemical synthesis / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared
D006847:Hydrocarbons, Iodinated; D011799:Quinazolines; D010165:Palladium
2-aryl-4-chloro-8-iodoquinazolines; cross-coupling reactions; photophysical properties; polycarbo-substituted quinazolines