HAT-DES · Development of Novel Desaturative Strategies for the Preparation of Aniline Building Blocks via Photoredox-Cobalt–HAT Triple Catalysis
Horizon Europe — Marie Skłodowska-Curie Actions
- Duration
- 2023-10-01 → 2025-09-30
- EU contribution
- €189,687
- Participants
- 1
- Scheme
- HORIZON-TMA-MSCA-PF-EF
Lines connect the coordinator with its partners.
Results in brief
Development of Novel Desaturative Strategies for the Preparation of Aniline Building Blocks via Photoredox-Cobalt–HAT Triple Catalysis
The completed work is comprised of two projects, with the aims as outlined herein: (1) devise a strategy to enable controlled oxidative deconstruction of stable aromatic molecules in the presence of more reactive alkenes and, (2) design a metal-free method for the hydrogenation of alkenes which tolerates functional groups usually labile under traditional transition-metal catalysed hydrogenation reactions. Project 1: Ozonlysis of aromatics in the presence of alkenes Prior to this work, the controlled oxidative cleavage of aromatic rings represented an attractive, but inherently challenging proposition, because it requires the selective dismantling of a stable aromatic π-system in the presence of more reactive C=C bonds, that are formed after initial dearomatisation. For this reason, the ozonolysis of arenes results in destructive over-oxidation and is not synthetically useful. Other limitations of ozone include poor compatibility with several common functional groups/heterocycles found in pharmaceuticals and safety concerns. This worked seeked to address the fundamental challenge of arene ozonolysis and thereby enable a new mode of fundamental chemical reactivity: achieving chemoselective oxidative cleavage of arenes in the presence of more reactive π-systems (i.e. olefins). Project 2: Chemoselective photochemical hydrogenation of alkenes using ammonia borane. The heterogeneous metal-catalysed hydrogenation of alkenes is one of the most robust and important transformations for the generation of valuable chemicals in both industry and academia. However, the selective catalytic hydrogenation of alkenes in the presence of functional groups such as azides, benzyl ethers and epoxides can be challenging. This work aimed to develop of an original gas- and metal-free method for selective hydrogenation of alkenes in the presence of functional groups often incompatible with traditional methods, thereby enabling the selective hydrogenation of olefins in complex molecules.
Data: CORDIS, © European Union
Project objective
Anilines and their derivatives are integral organic molecules with application as medicines, agrochemicals and organic materials. Over the last 30 years, the Buchwald-Hartwig and Ullmann cross-couplings have dominated the area of aromatic amination. These reactions involve palladium- or copper-catalyzed C-N bond formation between a halogenated aromatic and an amine. Only aromatics that have been halogenated will react with the metal catalysts and undergo cross-coupling. Therefore, although these processes are widely used, there are 2 significant challenges associated with them: a. aromatic halogenation reactions are often problematic in terms of selectivityb. cross-coupling reactions are known to fail on complex and functionalized materials With this project we aim to provide a transformative advance in the field and demonstrate the direct conversion of functionalized N-cyclohexyl-amides, carbamates and sulfonamides into the corresponding N-aryl derivatives. To achieve this, we will use an unprecedented triple catalysis manifold based on photoredox catalysis, cobalt catalysis and H-atom transfer catalysis. This innovative catalytic system will effectively trigger desaturation of the starting N-cyclohexyl derivatives and key reactive intermediates. This research will create a novel approach for the one-step synthesis of many complex anilines from unusual precursors, which are largely commercially-available or easy to prepare. The proposal capitalizes on recent developments by the host group in aniline synthesis and dual photoredox–cobalt catalysis.The development of this innovative project at RWTH Aachen University will create new tools in bio-organic chemistry and enable the rapid and efficient preparation of high-value materials. Implementation of the project will be facilitated by the generation, transfer, and dissemination of knowledge, which will greatly enhance my future career prospects, in accordance with the enviosioned training plan.
Original text from CORDIS.
Participants
- RHEINISCH-WESTFAELISCHE TECHNISCHE HOCHSCHULE AACHEN · AachenCoordinatorGermany
Links
- View on CORDIS
- DOI: 10.3030/101102820
- https://ec.europa.eu/research/participants/documents/downloadPublic?documentIds=080166e51a55ccb5&appId=PPGMS
- https://ec.europa.eu/research/participants/documents/downloadPublic?documentIds=080166e5258d1c75&appId=PPGMS
Data: CORDIS, © European Union