{
  "abstract": "Medium-sized aliphatic rings are underrepresented in drug discovery despite their advantageous balance of rigidity and flexibility. Existing synthetic limitations hinder broader exploration of this valuable chemical space. This work presents a general and efficient method for the one- and two-carbon ring expansion of 5- and 6-membered allylic alcohols to larger cyclic ketones using cerium-based photoredox catalysis. Employing ligand-to-metal charge transfer (LMCT) activation, a dual catalytic system featuring Ce(OTf)3 and 9,10-diphenylanthracene (DPA) enables selective generation of alkoxyl radicals under mild conditions. A hydrogen atom transfer (HAT) catalyst, (TRIPS)2, is critical for productive C–C bond formation and radical termination. The method tolerates various nitrogen-protecting groups, vinyl substitutions, and ring systems, including bridged and fused frameworks, affording 7- and 8-membered ketones in moderate to excellent yields (38–98%). Notably, expansion to challenging [5.2.1] bicyclic and fused benzannulated scaffolds is demonstrated. This strategy offers a divergent and synthetically accessible route to sp3-rich, conformationally diverse drug-like scaffolds from simple precursors.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "name": "Tegan E. O’Brien"
    },
    {
      "name": "Vamika Kaushal"
    },
    {
      "name": "Avery O. Morris"
    },
    {
      "name": "Louis Barriault",
      "orcid": "0000-0003-2382-5382"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7zaepyysahf14.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15010888/v1",
  "fulltext_url": null,
  "id": "7zaepyysahf14",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010888/v1",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "1605|Radical Photochemical Reactions"
    ]
  ],
  "openalex": "W7223175172",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15010888/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-22",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/7zaepyysahf14.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:26Z",
      "native_id": "10.26434/chemrxiv.15010888",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010888/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:1605|Radical Photochemical Reactions",
      "subfield": "organic"
    }
  ],
  "title": "Cerium Photoredox-Catalyzed Ring Expansion of Cyclic Allylic Alcohols",
  "title_text": "Cerium Photoredox-Catalyzed Ring Expansion of Cyclic Allylic Alcohols",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:26Z",
  "url": "https://research.draconitic.com/paper/7zaepyysahf14",
  "venue": "ChemRxiv",
  "versions": []
}