Dearomative Ring Expansion of Polycyclic Arenes.

Angew Chem Int Ed Engl

Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100, Pavia, Italy.

Published: September 2022

Benzocycloheptenes constitute a common structural motif embedded in many natural products and biologically active compounds. Herein, we report their concise preparation from non-activated polycyclic arenes using a two-step sequence involving dearomative [4+2]-cycloaddition with arenophile in combination with palladium-catalyzed cyclopropanation, followed by cycloreversion-initiated ring expansion. The described strategy provides a working alternative to the Buchner reaction, which is limited to monocyclic arenes. Overall, this methylene-insertion molecular editing approach enables rapid and direct conversion of simple (hetero)arenes into a range of substituted (aza)benzocycloheptatrienes, which can undergo a myriad of downstream functionalizations.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9543877PMC
http://dx.doi.org/10.1002/anie.202208014DOI Listing

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