# Atomically Dispersed Palladium Promoted Suzuki–Miyaura Cross Coupling

## TL;DR

A new isolated palladium catalyst on carbon nitride efficiently performs Suzuki coupling at room temperature without ligands.

## Contribution

An isolated Pd/PCN catalyst achieves high activity for Suzuki coupling under ligand-free and mild conditions.

## Key findings

- Pd/PCN with 2 wt% Pd loading shows the highest mole-specific activity for cross coupling.
- Isolated Pd species outperform Pd nanoparticles in catalytic activity.
- Reaction atmosphere affects catalytic performance, with O2 promoting side reactions.

## Abstract

The palladium‐catalyzed Suzuki–Miyaura cross coupling reaction to forge carbon‐carbon bonds fundamentally changes the practice of organic synthesis. Herein an isolated palladium catalyst supported on polymeric carbon nitride (Pd/PCN) for efficient cross coupling of bromobenzene and phenylboronic acid at room temperature is reported. It is demonstrated that the Pd/PCN catalyst with a 2 wt% Pd loading achieves the highest mole‐specific activity. In addition, the size of supported Pd can strongly affect the reaction performance: the isolated Pd species exhibit higher activity compared to the Pd nanoparticles. The continuous flow tests demonstrate that the catalytic properties of the Pd/PCN catalyst strongly depend on the reaction atmosphere: Pd‐catalyzed self‐coupling of phenylboronic acid as a side reaction is more pronounced under an O2 flow than in an Ar flow. Detailed mechanistic investigations through in situ infrared spectroscopy reveal the role of the base K2CO3 in activating the phenylboronic acid.

An isolated palladium catalyst supported on polymeric carbon nitride is prepared and applied for the Suzuki‐coupling reaction under ligand‐free conditions at room temperature. Moreover, in situ infrared spectroscopy reveals the role of the base K2CO3 and characterizes the dynamic changes in substrate consumption and product formation during the cross‐coupling process.© 2025 WILEY‐VCH GmbH