title: Cyclopenta[b]annulation of Heteroarenes by Organocatalytic γ'[C(sp3)-H] Functionalization of Ynones.
abstract: A new approach for the cyclopenta[b]annulation of heteroarenes through metal-free and directing-group-free γ'[C(sp3)-H] functionalization and intramolecular hydroalkylation of ynones has been developed. In an unprecedented event, nucleophilic addition of an organophosphine to the designed ynones triggers γ'[C(sp3)-H] functionalization, leading to the formation of heteroaryl-based ortho-quinodimethane (oQDM) intermediates that undergo carbocyclization to provide cyclopentannulated heteroarenes in good yields and excellent stereoselectivities. Deuterium-labeling experiments substantiated the proposed reaction mechanism as well as the speculated epimerization.
authors.affiliation: Organic Synthesis and Catalysis Lab, Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Manuali PO, S. A. S. Nagar, Punjab, 140306, India.
authors.forename: Moluguri
authors.initials: M
authors.lastname: Raghu
authors.affiliation: Organic Synthesis and Catalysis Lab, Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Manuali PO, S. A. S. Nagar, Punjab, 140306, India.
authors.forename: Jagdeep
authors.initials: J
authors.lastname: Grover
authors.affiliation: Organic Synthesis and Catalysis Lab, Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Manuali PO, S. A. S. Nagar, Punjab, 140306, India.
authors.forename: S S V
authors.identifier: http://orcid.org/0000-0001-5814-9092
authors.initials: SS
authors.lastname: Ramasastry
keywords: cyclopentannulation; heterocycles; hydroalkylation; organophosphines; ynones