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Cyclopenta[ b ]annulation of Heteroarenes by Organocatalytic γ′[C(sp 3 )−H] Functionalization of Ynones
Author(s) -
Raghu Moluguri,
Grover Jagdeep,
Ramasastry S. S. V.
Publication year - 2016
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201604562
Subject(s) - annulation , surface modification , epimer , chemistry , intramolecular force , nucleophile , stereochemistry , nucleophilic addition , medicinal chemistry , combinatorial chemistry , catalysis , organic chemistry
A new approach for the cyclopenta[ b ]annulation of heteroarenes through metal‐free and directing‐group‐free γ′[C(sp 3 )−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(sp 3 )−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.