Redox-neutral photocatalytic cleavage and <i>gem</i>-difluoroalkenylation of lignin linkages.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40815636.
- Also identified by DOI 10.1126/sciadv.ady2227 and PMC identifier 12356238.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The conversion of lignin into high-value-added chemicals represents a promising strategy to enhance its valorization. However, developing catalytic systems and reagents that enable the selective activation and functionalization of specific linkages within its complex polymeric structure remains highly challenging. Here, we report a photocatalytic method for the efficient cleavage and <i>gem</i>-difluoroalkenylation of β-O-4 and β-1 lignin models, as well as native lignin biomass. By using α-trifluoromethyl alkenes as functionalization reagents, this protocol provides a wide array of valuable <i>gem</i>-difluoroalkenes through proton-coupled electron transfer (PCET), β-scission, radical addition, and β-F elimination processes. This redox-neutral method features operational simplicity, good functional group compatibility, and excellent selectivity. In addition, the derivatization of the resulting <i>gem</i>-difluorobishomoallylic alcohol highlights its synthetic potential.