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Updated: Jun 12, 2026

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
Pyrrole synthesis via allylic sp3 C-H activation of enamines followed by intermolecular coupling with unactivated
Souvik Rakshit1, Frederic W Patureau, Frank Glorius
1NRW Graduate School of Chemistry, Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster, Germany.
Abstract:
A conceptually novel pyrrole synthesis is reported, efficiently merging enamines and (unactivated) alkynes under oxidative conditions. In an intermolecular Rh catalyzed process, the challenging allylic sp(3) C-H activation of the enamine substrates is followed by the cyclization with the alkyne (R(3) = CO(2)R). Alternatively, in some cases (R(3) = CN), the enamine can be utilized for a vinylic sp(2) C-H activation. A total of 17 examples with yields above 60% is presented, together with the results of an initial mechanistic investigation.
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