Heterogeneous Iridium-Catalyzed Carbene N–H Bond Insertion with α-Alkyl Diazo Esters

Abstract

A heterogeneous iridium single-atom site catalyst (Ir-SA) was synthesized and investigated in catalyzing the carbene insertion reaction with challenging α-alkyl diazo ester substrates. With only 0.23 mol % catalyst loading, our Ir-SA demonstrated remarkable performance in heterogeneous carbene N−H bond insertion reactions involving various (hetero) aryl amines coupled with α-alkyl diazo esters. Notably, in the case of using a chiral diamino substrate with two reactive sites, Ir-SA exhibited high selectivity toward single carbene N−H insertion, leading to the generation of a class of unsymmetric chiral diamino ligands. Further mechanism study revealed that the lower activation barrier associated with the single N−H bond insertion step, as compared to either β-hydride elimination or downstream dual N−H bond insertion, accounted for the remarkable selectivity observed in this carbene insertion reaction catalyzed by Ir-SA.

Regulating the coordination microenvironment of zinc single-atom catalysts to enhance intramolecular hydroamination performance

“…Single-atom catalysts (SACs) have attracted considerable attention in recent years due to their ability to maximize atom utilization, exhibit distinctive electronic properties, and provide uniform and adjustable active sites. 14–30 SACs’ well-defined active sites also serve as an ideal model to gain comprehensive insights into catalytic reaction mechanisms at an atomic scale. 24–27 From a coordination chemistry perspective, the catalytic activity of SACs is closely related to their local coordination microenvironment.…”

Copper-Catalyzed Sulfur Alkylation of Sulfenamides with N-Sulfonylhydrazones

“…Despite recent progress, the diazo precursors utilized in current strategies are predominantly limited to the acceptor-type diazo compounds. Given the easy preparation and prevalence of aldehyde-derived hydrazones as donor-type carbene precursors, along with their rich chemistry in coupling reactions, we present herein the development of copper-catalyzed sulfur alkylation of sulfenamides with N -sulfonylhydrazones.…”