Pd-Catalyzed Dearomative [3 + 2] Cycloaddition of 3-Nitroindoles with 2-Vinylcyclopropane-1,1-dicarboxylates

Yi Sing Gee; Daniel J Rivinoja; Steven M Wales; Michael G Gardiner; John H Ryan; Christopher J T Hyland

doi:10.1021/acs.joc.7b02624

Pd-Catalyzed Dearomative [3 + 2] Cycloaddition of 3-Nitroindoles with 2-Vinylcyclopropane-1,1-dicarboxylates

J Org Chem. 2017 Dec 15;82(24):13517-13529. doi: 10.1021/acs.joc.7b02624. Epub 2017 Dec 4.

Authors

Yi Sing Gee¹, Daniel J Rivinoja¹, Steven M Wales¹, Michael G Gardiner², John H Ryan³, Christopher J T Hyland¹

Affiliations

¹ School of Chemistry, University of Wollongong , Wollongong, New South Wales 2522, Australia.
² School of Physical Sciences - Chemistry, University of Tasmania , Hobart, Tasmania 7001, Australia.
³ Biomedical Manufacturing Program, CSIRO Manufacturing, Clayton, Victoria 3168, Australia.

PMID: 29129063
DOI: 10.1021/acs.joc.7b02624

Abstract

A trans-diastereoselective Pd-catalyzed dearomative [3 + 2] cycloaddition between vinylcyclopropane dicarboxylates and 3-nitroindoles has been developed. The reaction provides densely functionalized cyclopenta[b]indolines with versatile vinyl and nitro-groups. The addition of a halide additive was found to be critical for the diastereoselectivity of the reaction, which is proposed to be a result of a rapid π-σ-π interconversion between the intermediates allowing for Curtin-Hammett control. A switch in diastereoselectivity to afford products with the vinyl and nitro groups cis to each other is observed with a 4-substituted 3-nitroindole.