Novel bifunctional HAT catalysts for site-divergent C-H functionalizations mediated by photoredox catalysis

Informations projet

BICACH

N° de convention de subvention: 838108

DOI

10.3030/838108

Projet clôturé le 31 Janvier 2020

Date de signature de la CE 8 Avril 2019

Date de début 1 Mai 2019

Date de fin 30 Avril 2021

Financé au titre de

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Coût total

€ 162 806,40

Contribution de l’UE

€ 162 806,40

Coordonné par

UNIVERSITAET REGENSBURG
Germany

Periodic Reporting for period 1 - BICACH (Novel bifunctional HAT catalysts for site-divergent C-H functionalizations mediated by photoredox catalysis)

Période du rapport: 2019-05-01 au 2021-04-30

Résumé du contexte et des objectifs généraux du projet

Alkanes are the major components of natural gas and oil which are abundantly produced by the petrochemical industry. They are almost exclusively used as a source of energy following their combustion which can be considered as a waste of a carbon-based feedstock. From the organic chemist’s point of view, alkanes indeed represent a major carbon pool for chemical synthesis which remains poorly explored. To date, the elaboration of complex organic molecules heavily relies on the introduction and manipulation of functional groups, typically carbon-oxygen or carbon-halogen bonds. In this regard, the direct functionalization of aliphatic carbon-hydrogen (C-H) bonds, the most abundant moiety within alkanes, represents a more ideal approach to access molecular complexity. However, there are two major hurdles toward he application of this strategy. First, alkane C-H bonds are very difficult to activate. However, if one can overcome this lack of reactivity, it should then face a daunting selectivity issue: how to activate selectively one single C-H bond within an alkane backbone harnessing many almost identical C-H bonds?

The development of chemical processes enabling the selective conversion of cheap and abundant alkanes into high-value chemicals is one of the Holy grail in organic synthesis. Such endeavour would strongly benefit our society 1) By reducing the amount of chemical waste to access valuable chemical products; 2) By enabling the synthesis of new chemicals with unprecedented properties.

The main objective of this project was to develop a library of small molecules enabling the selective functionalization of alkane through catalytic processes using visible light as a renewable source of energy.

Travail effectué depuis le début du projet jusqu’à la fin de la période considérée dans le rapport et principaux résultats atteints jusqu’à présent

Indoles are prevalent motifs in bioactive natural products and pharmaceuticals. Therefore, the development of methods for the synthesis of functionalized of indoles under mild conditions is an important task in synthetic chemistry. In this respect, catalytic transformations enabling the direct functionalization of indole C-H bonds are particularly valuable because they afford complex indole structures with an excellent step and atom-economy. During the BICACH project, we developed a catalytic process to access a range of relevant indoles through selective C-H functionalization. This process is mediated by visible light as a renewable source of energy.

Progrès au-delà de l’état des connaissances et impact potentiel prévu (y compris l’impact socio-économique et les conséquences sociétales plus larges du projet jusqu’à présent)

We developed a photocatalytic C-H functionalization strategy mediated by visible light that provides an efficient access to a variety of novel relevant polycyclic indoles. The reaction is scalable and the indole products can be further used as versatile synthetic intermediates to access other important scaffolds such as pyrroloindoles and (pyrrolo)indolines. We expect this methodology to find a widespread use in the synthesis of indole-containing natural products and bioactive compounds. Given the diversity of bioactive profiles amongst indole containing molecules, this project could have wider societal implications through the development of novel medicines.

Synthesis of functionalized indoles by C-H alkylation