1. Synthesis of New Polyfluoroaryl Materials. 2. New Transition Metal Catalysts for Enantioselective C – H Bond Functionalization.
Date
2021-12
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Abstract
- Synthesis of new polyfluoroaryl materials. Polyfluorinated porous materials are essential in sequestration of fluorine pollutants due to their high water resistance and fluorophilic ability. In 2014, our and Dr. Miljanic group introduced a triangular porous material prepared from perfluoro organic compounds, showing remarkably selective adsorption toward halogenated hydrocarbons. Based on the precedent published in 2014, we attempted to increase the pore size of this material by inserting 2,2’-bipyridine groups on each linkage arm. Furthermore, modification of central arene groups was accomplished by using 1,3,5-triazine or 1,3,5-trifluorobenzene. In addition, ferrocene based fluorine material and two tetragonal fluorine compounds containing pyrene and tetraphenylethylene core were successfully synthesized by using copper catalysis as a main step. Among these compounds, tetraphenylethylene-based structure showed different emissive behaviors under ‘wet’ and ‘dry’ conditions. Other fluorinated tetraphenylethylene compounds such as (Z)/(E)-bis(pentafluorophenyl)stilbene, and tris(pentafluorophenyl)ethylene were synthesized using copper catalysis. In addition, their reactivity and selectivity in photocyclization reactions was also explored.
- New transition metal catalysts for enantioselective C – H bond functionalization. Enantioselective carbon-hydrogen bond functionalization using transition metal catalysis is one of the most powerful tools in organic synthesis. This method offers a straightforward route to obtain enantiopure isomer compounds. Thus, in the second part of this dissertation, two new types of potential chiral catalysts were developed and their reactivity was explored. A series of new C3-symmetric tridentate sulfur-containing ligands were synthesized. Various transition metals such as rhodium, iridium, ruthenium, and copper were coordinated to these ligands. In addition, catalytic activity of copper(I) and ruthenium (II) complexes was proved in carbene and nitrene C-H insertion reactions. Finally, aminoquinoline-directed enantioselective coupling of sp2 C-H bonds with alkenes using new cobalt catalyst was explored. The catalyst tolerates a broad substrates scope such as styrenes and aliphatic alkenes, giving low to medium level of enantioselectivity. This result may open an opportunity in asymmetric functionalization using bidentate directing groups, which sp far has proven very difficult.
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Keywords
Polyfluoro materials. Organo
Citation
Portions of this document appear in: Zhang, Z.; Lieu, T.; Wu, C.-H.; Wang, X.; Wu, J. I.-C.; Daugulis, O.; Miljanic, Solvation-Dependent Switching of Solid-state Luminescence of a Fluorinated Aromatic Tetrapyrazole. Chem. Commun. 2019, 55, 9387–9390.