Synthesis of Indoles and Pyrroles Utilizing Iridium Carbenes Generated from Sulfoxonium Ylides.
Metal carbenes can undergo a myriad of synthetic transformations. Sulfur ylides are potential safe precursors of metal carbenes. Herein, we report cascade reactions that involve carbenoids derived from sulfoxonium ylides for the efficient and regioselective synthesis of indoles and pyrroles. The tandem action of iridium and Brønsted acid catalysts enables rapid assembly of the heterocycles from unmodified anilines or readily accessible enamines under microwave irradiation. The key mechanistic steps are the catalytic transformation of the sulfoxonium ylide into an iridium-carbene complex, followed by N-H or C-H functionalization of an aniline or enamine, respectively, and a final acid-catalyzed cyclization. The present method was successfully applied to the synthesis of the densely functionalized pyrrole subunit of atorvastatin.
Department of Chemistry and Centre for Theoretical and Computational Chemistry (CTCC), University of Tromsø, 9037, Tromsø, Norway.
Janakiram
0000-0003-4068-5916
J
Vaitla
Department of Chemistry, University of Tromsø, 9037, Tromsø, Norway.
Annette
0000-0003-3481-200X
A
Bayer
Department of Chemistry and Centre for Theoretical and Computational Chemistry (CTCC), University of Tromsø, 9037, Tromsø, Norway.
Kathrin H
0000-0003-2798-716X
KH
Hopmann
heterocycles; indoles; metal carbenes; pyrroles; sulfur ylides