Photocatalytic Smiles Rearrangement at Remote C(sp<sup>3</sup>)–H Bonds
A photochemical method enables sequential difluoromethylation and distal Smiles rearrangement at positions C11 and C6 of unactivated alkenes through 1,5-hydrogen atom transfer. This C(sp<sup>3</sup>)-H activation bypasses proximity constraints, allowing the selective and efficient construction of oxindole frameworks. The organophotocatalyst 4DPNIPN catalyzes the transformation and proceeds via a radical-polar crossover mechanism initiated through oxidative luminescence quenching. The reaction operates under redox-neutral conditions without transition metals, stoichiometric oxidants, or additives. This protocol demonstrates excellent sustainability, broad functional group tolerance, and scalability and represents the first reported approach for synthesizing oxindole via selective distal C(sp<sup>3</sup>)-H activation.
Authors
- S. Giri
- Devarajulu Sureshkumar (ORCID: https://orcid.org/0000-0002-6985-3496)
- Koustav Pal
- Manasi Mallick
Institutions
- Indian Institute of Science Education and Research Kolkata (IN)
Publication Details
- Journal
- Organic Letters
- Published
- 2025-08-21
- DOI
- https://doi.org/10.1021/acs.orglett.5c02666
- Citations
- 1
- Primary Topic
- Catalytic C–H Functionalization Methods
- Type
- article
- Field-Weighted Citation Impact
- 0.94
Funders
- Council of Scientific and Industrial Research, India
- University Grants Commission
- Indian Institute of Science Education and Research Kolkata
- Science and Engineering Research Board