{
  "abstract": "We report an organocatalytic enantioselective [2π+2σ] cycloaddition mediated by visible-light for the dearomatization of indoles. The transformation provides rapid access to complex and sp3-rich indoline-based polycycles with excellent levels of diastereo- and enantiocontrol (up to >20:1 d.r. and 96% ee), through the tripletstate reactivity of a chiral iminium ion. Central to the development of this process was the identification of a suitable chiral primary amine organocatalyst, together with the generation and spectroscopic characterization of the corresponding triplet excited state by time-resolved EPR spectroscopy. The methodology displays broad substrate scope (31 examples) across diverse indoles, bicyclobutanes, and exocyclic alkenes, providing efficient access to highly functionalized bicyclo[2.1.1]hexanes and valuable spirocyclic indoline architectures.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Chemical Sciences, University of Padova, Via Marzolo 1, Padova, Italy, 35131",
    "Department of Organic and Inorganic Chemistry, University of the Basque Country (UPV/EHU, P.O. Box 644, Bilbao, Spain, 48080",
    "Departamento de Química Orgánica, Universidad de Alicante, Ctra. Alicante-San Vicente s/n, Alicante, Spain, 03080"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Vasco Corti"
    },
    {
      "affs": [
        0
      ],
      "name": "Raphael Dollet"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Gorka Garay"
    },
    {
      "affs": [
        0,
        2
      ],
      "name": "María González Marcos"
    },
    {
      "affs": [
        0
      ],
      "name": "Serafino Mastroianni"
    },
    {
      "affs": [
        0
      ],
      "name": "Marco Bortolus"
    },
    {
      "affs": [
        0
      ],
      "name": "Luca Dell’Amico"
    },
    {
      "name": "Luca Dell'Amico",
      "orcid": "0000-0003-0423-9628"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ffex95hmzt2d1.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15008273/v1",
  "fulltext_url": null,
  "id": "ffex95hmzt2d1",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008273/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": "W7208769877",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15008273/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-03",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/ffex95hmzt2d1.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:17Z",
      "native_id": "10.26434/chemrxiv.15008273",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008273/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:1605|Radical Photochemical Reactions",
      "subfield": "organic"
    }
  ],
  "title": "Stereoselective Dearomative [2π+2σ] Cycloadditions of Indoles Enabled by Triplet-State Iminium Ion Reactivity",
  "title_text": "Stereoselective Dearomative [2π+2σ] Cycloadditions of Indoles Enabled by Triplet-State Iminium Ion Reactivity",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:17Z",
  "url": "https://research.draconitic.com/paper/ffex95hmzt2d1",
  "venue": "ChemRxiv",
  "versions": []
}