Gorai Mahadeb, Franzen Jonas H, Rotering Philipp, Rüffer Tobias, Dielmann Fabian, Teichert Johannes F
Institut für Chemie, Technische Universität Chemnitz, Straße der Nationen 62, 09111 Chemnitz, Germany.
Department of General, Inorganic and Theoretical Chemistry, Universität Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria.
J Am Chem Soc. 2025 Apr 30;147(17):14481-14490. doi: 10.1021/jacs.5c01339. Epub 2025 Apr 16.
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 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 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.
一种由铜（I）/N-杂环卡宾配合物和碱性2-亚氨基吡啶亚基组成的高活性双功能催化剂，能在低氢气压力下实现氢化铜化学过程，达到1巴（气球压力）的高效催化。该双功能催化剂在催化炔烃半氢化反应中能耐受多种官能团。此外，这种催化剂设计具有高反应活性，首次实现了在低氢气压力下对α,β-不饱和酰胺（这是一类迄今在氢化铜催化中无反应活性的底物）的催化氢化。通过这种方式，基于丰富铜资源的第一行过渡金属催化剂催化氢化，可实现生物活性化合物中常见亚基α,β-不饱和酰胺的后期修饰和同位素标记。初步机理实验表明，双功能催化剂通过亚氨基吡啶介导的邻近效应起作用。我们推测，作为质子源的醇在铜（I）配合物上的配位通过快速的质子去铜步骤促进了整体反应。
