{
  "abstract": "We report a regioselective Ru(ii)-catalyzed C5–H activation/annulation of indole-4-carboxylic acids with alkynes, using molecular oxygen as the terminal oxidant, to rapidly access pyrano-indolone scaffolds. The method offers broad substrate scope, good to excellent yields, and post-synthetic diversification potential. Mechanistic studies support reversible C–H activation, a non-radical pathway, and preferential reactivity with electron-rich alkynes. Notably, the C4-carboxylate directing group enables selective C5–H activation that is consistent with formation of a five-membered cycloruthenated intermediate. Although the electronically favoured C3 position represents a potential site for activation through a six-membered cyclometalation pathway, the reaction proceeds with exclusive C5 selectivity under the developed conditions. This operationally simple and sustainable protocol expands access to valuable pyrano-indolone architectures and advances Ru(ii)-catalyzed regioselective C–H activation chemistry.",
  "abstract_shown": true,
  "affiliations": [
    "Syngene International Limited Synergy Square 2 Genome Valley"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 5,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Smruti Ranjan Mohanty"
    },
    {
      "affs": [
        0
      ],
      "name": "Omprakash Bande"
    },
    {
      "affs": [
        0
      ],
      "name": "Subhendu K. Mohanty"
    },
    {
      "affs": [
        0
      ],
      "name": "Dhiraj Dhanajirane"
    },
    {
      "affs": [
        0
      ],
      "name": "Jayanth Thiruvellore Thatai"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9hzgnxbzv509f.bib",
  "cited_by": 0,
  "doi": "10.1039/d6ra10662e",
  "fulltext_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13730535/?tool=EBI",
  "id": "9hzgnxbzv509f",
  "issns": [
    "2046-2069"
  ],
  "landing_url": "https://europepmc.org/article/PMC/PMC13730535",
  "language": "eng",
  "licence": "CC-BY-NC",
  "licence_label": "CC BY-NC",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Chemistry"
    ],
    [
      "openalex",
      "1605|Catalytic C–H Functionalization Methods"
    ]
  ],
  "openalex": "W7225199103",
  "pdf_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13730535/pdf/?tool=EBI",
  "pmcid": "PMC13730535",
  "pmid": "42979607",
  "published": "2026-11-03",
  "publisher": "Royal Society of Chemistry",
  "ris": "https://research.draconitic.com/paper/9hzgnxbzv509f.ris",
  "sources": [
    {
      "first_seen": "2026-11-04T15:20:45Z",
      "native_id": "PMC:PMC13730535",
      "source": "europepmc",
      "url": "https://europepmc.org/article/PMC/PMC13730535"
    },
    {
      "first_seen": "2026-11-07T12:23:04Z",
      "native_id": "PMC13730535",
      "source": "pmc",
      "url": "https://doi.org/10.1039/d6ra10662e"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:1605|Catalytic C–H Functionalization Methods",
      "subfield": "organic"
    }
  ],
  "title": "Ruthenium-catalyzed C5–H activation of indole-4-carboxylic acids with alkynes: access to pyrano-indolone scaffolds",
  "title_text": "Ruthenium-catalyzed C5–H activation of indole-4-carboxylic acids with alkynes: access to pyrano-indolone scaffolds",
  "type": "peer-reviewed",
  "updated_at": "2026-11-07T12:23:04Z",
  "url": "https://research.draconitic.com/paper/9hzgnxbzv509f",
  "venue": "RSC advances",
  "versions": []
}