Heck Migratory Insertion Catalyzed by a Single Pt Atom Site

Abstract

Single-atom catalysts (SACs) have generated excitement for their potential to downsize metal particles to the atomic limit with engineerable local environments and improved catalytic reactivities and selectivities. However, successes have been limited to small-molecule transformations with little progress toward targeting complex-building reactions, such as metal-catalyzed cross-coupling. Using a supercritical carbon-dioxide-assisted protocol, we report a heterogeneous single-atom Pt-catalyzed Heck reaction, which provides the first C–C bond-forming migratory insertion on SACs. Our quantum mechanical computations establish the reaction mechanism to involve a novel C-rich coordination site (i.e., PtC4) that demonstrates an unexpected base effect. Notably, the base was found to transiently modulate the coordination environment to allow migratory insertion into an M–C species, a process with a high steric impediment with no previous example on SACs. The studies showcase how SACs can introduce coordination structures that have remained underexplored in catalyst design. These findings offer immense potential for transferring the vast and highly versatile reaction manifold of migratory-insertion-based bond-forming protocols to heterogeneous SACs.

Mechanism of Nitrogen Coordination Modulation of Fe_Nx@BP System Catalysts on the Activity of Oxygen Reduction Reaction

“…For example, Liu et al prepared a highly durable Fe–N–C catalyst via a pyridine N-coordinated FeN 4 site . Li et al described a new multiphase single-atom Pt-catalyzed Heck reaction, which for the first time enabled the migratory insertion of a single-atom site M-C species . Zhou et al proposed a new single-atom P/Fe–N–C material that can be used as a bifunctional oxygen electrocatalyst for rechargeable zinc-air batteries .…”

Single-Atom Catalysts through Pressure-Controlled Metal Diffusion

“…When supported nanoparticles are downsized to the single-atom limit, the resulting single-atom catalysts (SACs) have proven especially valuable. − These individually dispersed metal sites possess defined coordination structures, enabling reaction pathways that differ from those of traditional heterogeneous catalysis. For instance, our group has recently reported carbon–carbon bond formation by a heterogeneous single-atom Pt-catalyzed Heck reaction . While offering high stability even in harsh environments and maximum utilization of catalytic metals, SACs also satisfy the key goals of sustainable chemistry. − Nevertheless, limited reproducibility and scalability of SAC preparation hinder their further practical applications, and efficient methods of SAC synthesis are urgently needed. , …”