Mechanochemical Rhodium(III)- and Gold(I)-Catalyzed C-H Bond Alkynylations of Indoles under Solventless Conditions in Mixer Mills

Gary N Hermann; Marvin T Unruh; Se-Hyeong Jung; Maik Krings; Carsten Bolm

doi:10.1002/anie.201805778

Mechanochemical Rhodium(III)- and Gold(I)-Catalyzed C-H Bond Alkynylations of Indoles under Solventless Conditions in Mixer Mills

Angew Chem Int Ed Engl. 2018 Aug 13;57(33):10723-10727. doi: 10.1002/anie.201805778. Epub 2018 Jun 28.

Authors

Gary N Hermann¹, Marvin T Unruh¹, Se-Hyeong Jung¹, Maik Krings¹, Carsten Bolm¹

Affiliation

¹ Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany.

PMID: 29889348
DOI: 10.1002/anie.201805778

Abstract

Mechanochemical activations in Rh^III - and Au^I -catalyzed C-H alkynylations lead selectively to C₂ - and C₃ -alkynylated indoles. The processes show excellent functional group tolerance, do not require additional heating and proceed under solventless conditions. Compared to solvent-based standard protocols, the reaction times are shorter and the catalyst quantities lower resulting in high product yields under ambient atmosphere in mixer mills.

Keywords: C−H alkynylation; ball mill; gold catalysis; mechanochemistry; rhodium catalysis.