α-amino radicals induced by an Fe(III) N heterocyclic carbene photosensitizer
(2024) KEMP30 20232Department of Chemistry
- Abstract
- Photoredox catalysis with 1st row transition metals is an expanding, but challenging field of research. Using iron complexes as useful catalysts is especially difficult due to low exited state lifetimes and the need for suitable redox-potentials of the involved ground and excited states. The use of strongly σ-donating NHC-ligands led to exited state lifetimes in the pico- and nanosecond region, while showing promising redox-potentials and good visible light absorption. Those catalysts have recently found application in the catalysis of photoreactions, but examples of their successful usage remain scarce. The herein investigated iron complex is successfully used to catalyze visible light-mediated aminomethylations of electron deficient... (More)
- Photoredox catalysis with 1st row transition metals is an expanding, but challenging field of research. Using iron complexes as useful catalysts is especially difficult due to low exited state lifetimes and the need for suitable redox-potentials of the involved ground and excited states. The use of strongly σ-donating NHC-ligands led to exited state lifetimes in the pico- and nanosecond region, while showing promising redox-potentials and good visible light absorption. Those catalysts have recently found application in the catalysis of photoreactions, but examples of their successful usage remain scarce. The herein investigated iron complex is successfully used to catalyze visible light-mediated aminomethylations of electron deficient systems. Functionalization of sp3-CH-bonds adjacent to the N-atom of amines was driven by an iron-N-heterocyclic carbene complex, circumventing the use of noble metal photocatalysts. The scope highlights the importance of the electronic match between the substrates. A visible light-mediated homolytic aromatic substitution reaction with α-aminoalkyl radicals is optimized and control reactions show a strong background reaction that takes place without catalyst present. The results obtained herein provide further motivation for continued investigations of the reactivity and synthetic utility of [Fe(phtmeimb)2](PF6) and comparable complexes. (Less)
- Popular Abstract
- Synthetic organic compounds are one of the building blocks in modern society. Chemicals are employed as fertilizers, to build houses or to produce pharmaceuticals. The scale of products required makes considerations regarding their sustainability a necessary research question. One of the answers to these questions is the use of catalysis. Catalysts are compounds that enable or speed up chemical reactions while not being consumed themselves. Thereby they are often creating less waste. The presented work is focused on photocatalysts that are activated by using visible light, which could in an ideal scenario be harvested directly from sunlight.
Another aspect of sustainability is avoiding the usage of scarce and expensive metals which are... (More) - Synthetic organic compounds are one of the building blocks in modern society. Chemicals are employed as fertilizers, to build houses or to produce pharmaceuticals. The scale of products required makes considerations regarding their sustainability a necessary research question. One of the answers to these questions is the use of catalysis. Catalysts are compounds that enable or speed up chemical reactions while not being consumed themselves. Thereby they are often creating less waste. The presented work is focused on photocatalysts that are activated by using visible light, which could in an ideal scenario be harvested directly from sunlight.
Another aspect of sustainability is avoiding the usage of scarce and expensive metals which are often seen in catalytic applications. Recently, attempts have been made to substitute scarce metals like iridium or ruthenium with metals that occur more often on earth such as iron. But as such compounds have not been extensively employed before, their application is still challenging and investigations are necessary. The aim of the presented work is testing an already developed catalyst in reactions that were previously done with less sustainable compounds. This is necessary to understand the applicability and limitations of the newly developed catalyst and to find possible improvements. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9148300
- author
- Hainz, Simon LU
- supervisor
- organization
- course
- KEMP30 20232
- year
- 2024
- type
- L3 - Miscellaneous, Projetcs etc.
- subject
- keywords
- Homolytic aromatic substitution, iron, Michael-acceptor, Photoredox catalysis, Radical
- language
- English
- id
- 9148300
- date added to LUP
- 2024-02-09 15:29:03
- date last changed
- 2024-02-09 15:29:03
@misc{9148300,
abstract = {{Photoredox catalysis with 1st row transition metals is an expanding, but challenging field of research. Using iron complexes as useful catalysts is especially difficult due to low exited state lifetimes and the need for suitable redox-potentials of the involved ground and excited states. The use of strongly σ-donating NHC-ligands led to exited state lifetimes in the pico- and nanosecond region, while showing promising redox-potentials and good visible light absorption. Those catalysts have recently found application in the catalysis of photoreactions, but examples of their successful usage remain scarce. The herein investigated iron complex is successfully used to catalyze visible light-mediated aminomethylations of electron deficient systems. Functionalization of sp3-CH-bonds adjacent to the N-atom of amines was driven by an iron-N-heterocyclic carbene complex, circumventing the use of noble metal photocatalysts. The scope highlights the importance of the electronic match between the substrates. A visible light-mediated homolytic aromatic substitution reaction with α-aminoalkyl radicals is optimized and control reactions show a strong background reaction that takes place without catalyst present. The results obtained herein provide further motivation for continued investigations of the reactivity and synthetic utility of [Fe(phtmeimb)2](PF6) and comparable complexes.}},
author = {{Hainz, Simon}},
language = {{eng}},
note = {{Student Paper}},
title = {{α-amino radicals induced by an Fe(III) N heterocyclic carbene photosensitizer}},
year = {{2024}},
}