Abstract
The LIGHT-CAT project aims to develop new sustainable catalytic strategies by merging visible-light photochemistry with modern catalytic platforms, including metal catalysis and organocatalysis. The goal is to design efficient and selective methods for the direct functionalisation of simple and abundant molecules, such as alkanes and natural products, with minimal environmental impact. By exploiting the power of visible light as a renewable energy source, the project will enable novel radical-based transformations through Hydrogen Atom Transfer (HAT) processes. These will allow direct activation of strong, otherwise inert, C(sp³)–H bonds, offering streamlined access to complex and valuable chemical structures. The project is carried out by a consortium of three teams: the University of Bologna (Paolo Melchiorre, project coordinator), the University of Pavia (Maurizio Fagnoni), and the University of Roma Tor Vergata (Massimo Bietti). Their complementary expertise in photochemistry, radical catalysis, and sustainable synthesis ensures a synergistic and interdisciplinary approach. The expected outcomes include the discovery of new light-driven catalytic processes, the development of more sustainable synthetic tools, and a deeper understanding of reaction mechanisms. LIGHT-CAT ultimately contributes to the advancement of green chemistry and the design of low-impact, innovative chemical technologies. Achieved Results During the project, the LIGHT-CAT consortium developed and validated visible-light-driven strategies for the selective functionalisation of strong C(sp³)–H bonds through Hydrogen Atom Transfer (HAT)-based radical processes. The work integrated the complementary expertise of the Bologna, Pavia and Roma Tor Vergata units in photochemical radical catalysis, HAT reactivity, asymmetric synthesis, metal catalysis and mechanistic analysis. The main scientific outcome was the development of a HAT-enabled, nickel-catalyzed asymmetric C(sp³)–C(sp³) cross-coupling platform. In this approach, carbon-centered radicals generated directly from aliphatic C–H bonds are intercepted by a chiral nickel catalyst, enabling stereocontrolled C–C bond formation. The project established a desymmetrization strategy for meso C–H-rich substrates, including piperidine frameworks of medicinal relevance, reaching advanced levels of optimization, mechanistic understanding and synthetic potential. A second research line explored stereocontrolled C(sp³)–H functionalisation through the combination of radical generation and asymmetric organocatalysis. These studies delivered proof-of-concept results and clarified key mechanistic requirements for aldehyde-enabled radical desymmetrization processes. A third line investigated the merger of HAT chemistry with pyridinium radical reactivity for C4-selective pyridine functionalisation; although this direction did not lead to a general synthetic method within the project timeframe, it provided valuable boundary conditions and helped refine the overall research strategy. The project generated open-access scientific outputs and a strong publication pipeline, including mechanistic studies on HAT reactivity, the development of organic photocatalysts and manuscripts reporting the main methodological advances. Results were disseminated through publications, invited and plenary lectures, oral communications at international conferences, consortium meetings and training activities involving early-career researchers. Overall, LIGHT-CAT achieved its central objective of advancing sustainable, light-driven catalytic methods for radical C(sp³)–H functionalisation, while providing new mechanistic insight and innovative tools for green synthetic chemistry. The project received financial support from the European Union - NextGenerationEU under the PRIN 2022 PNRR programme.
Dettagli del progetto
Responsabile scientifico: Paolo Melchiorre
Strutture Unibo coinvolte:
Dipartimento di Chimica Industriale "Toso Montanari"
Coordinatore:
ALMA MATER STUDIORUM - Università di Bologna(Italy)
Contributo totale di progetto: Euro (EUR) 234.553,00
Contributo totale Unibo: Euro (EUR) 141.916,00
Durata del progetto in mesi: 24
Data di inizio
30/11/2023
Data di fine:
30/11/2025
