Work

Broadly Applicable Copper(I)-Catalyzed Alkyne Semihydrogenation and Hydrogenation of α,β-Unsaturated Amides Enabled by Bifunctional Iminopyridine Ligands

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide A highly active bifunctional catalyst consisting of a copper(I)/N-heterocyclic carbene complex and a basic 2-iminopyridine subunit allows for copper hydride chemistry under low H 2 pressure, achieving efficient catalysis reaching 1 bar (balloon pressure). The bifunctional catalyst tolerates a remarkable variety of functional groups in catalytic alkyne semihydrogenations. Furthermore, this catalyst design gives rise to a high reactivity that allows for the catalytic hydrogenation of α,β-unsaturated amides (a substrate class hitherto unreactive in copper hydride catalysis) at a low H 2 pressure for the first time. In this manner, late-stage modification and isotope labeling of α,β-unsaturated amides, common subunits in biologically active compounds, can be realized through catalytic hydrogenation using a first-row transition metal catalyst based on abundant copper. Preliminary mechanistic experiments indicate that the bifunctional catalyst operates via an iminopyridine-mediated proximity effect. We hypothesize that the coordination of an alcohol as a proton source on the copper(I) complex facilitates the overall reactions through a rapid proto-decupration step.

Source: Journal of the American Chemical Society

DOI: 10.1021/jacs.5c01339

Authors: Mahadeb Gorai, Jonas H. Franzen, Philipp Rotering, Tobias Rüffer, Fabian Dielmann, Johannes F. Teichert

Institutions: Chemnitz University of Technology, Universität Innsbruck

Language: English

Topic: Asymmetric Hydrogenation and Catalysis

Subfield: Inorganic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funder: Deutsche Forschungsgemeinschaft