Enabling Noble Metal Reactivity with Earth-Abundant Metals for Selective Bond Functionalization Strategies

Introduction

The functionalization of C=C and C–X bonds (X = I, Cl, Br, and H) is fundamental in organic chemistry for making carbon-carbon bonds or for introducing molecular complexity. Chemists have traditionally relied on precious metals catalysts such as palladium, platinum, and iridium to facilitate these transformations.

Scarcity of Precious Metals

Some of these metals, if not all of them, are among the rarest on earth, leading to increasingly high prices and uncertainty in future supply chains. As their availability continues to decline, it is important to address the scarcity of these metals to secure a sustainable future.

Alternative Solutions

One solution is to develop new technologies that allow one to substitute the precious metal catalysts for those that are abundantly available (e.g., iron), without sacrificing performance and selectivity.

Challenges with Iron

Because of the fundamental differences between the properties of iron (one-electron chemistry) and the second/third-row transition metals (two-electron chemistry), this approach has shown to be a daunting task. If, however, it could be shown that iron could reliably engage in two-electron chemistry, then the reactivity of precious metals could be unlocked for iron.

Research Approach

Through bespoke ligand design, we will attempt to unlock this two-electron chemistry and apply it to three of the most common reactions in organic synthesis:

1. Cross-coupling
2. Alkene metathesis
3. C–H bond functionalization

By relying on a distinct two-electron mechanism, a treasure trove of possibilities for selective bond-forming reactions is generated.

Expected Outcomes

Overall, this work is expected to result in new avenues in earth-abundant metal catalysis and provide new methodologies to construct ever-important C-C and C-N bonds that can be used to induce molecular complexity.