The document discusses principles of multimetallic catalysis for carbon-carbon bond formation. Key considerations in designing multimetallic systems include choosing complementary metals, favoring cross-reactivity between the metals to prevent self-reactivity, and optimizing systems with multiple metals and ligands. Multimetallic reactions can be classified based on how the metals interact, such as one metal transferring electrons to another, one metal activating a substrate that another metal then traps, or metals activating separate substrates that undergo group transfer between the metals.

1. Multimetallic Catalysis
Monometallic Catalysis Multimetallic Catalysis

2. Design Principles of Multimetallic Catalysis
Recent advances in multimetallic-catalyzed reactions for C−C bond formation reveal principles that can
be adopted in the design of new reactions.
Key considerations in devising multimetallic systems are
(1) choosing what metals to pair together,
(2) favoring cross-reactivity between catalysts to outcompete or prevent self-reactivity by one of
the catalysts, and
(3) optimizing more complex systems that contain multiple metals and multiple ligands.

3. Metal Catalyst Selection in Multimetallic Catalysis

4. Cu and Pd: A Prototypical Multimetallic Reaction
Sonogashira reaction

5. Ni and Cr: Complementary Reactivity of Early and
Late Metals in the Nozaki-Hiyama-Kishi Reaction

6. Ligand Choice Considerations in Multimetallic Catalysis

8. Ni and Pd: Cross−Ullmann Reaction Illustrating Selective
Transmetalation By the Persistent Metal Effect

9. Achieving Cross-Selectivity in Multimetallic Catalytic Reactions.

10. Negishi Coupling Illustrates How Reactivity and
Concentration Differences Can Influence Selectivity

11. Achieving Stereoselectivity in Multimetallic
Catalytic Reactions

14. . Ni and Co: Enantioselective Cross-Electrophile Coupling by
Stereoselective Reductive Elimination

15. Ru and Sc: Enantioselective Triplet Energy Transfer
Enabled by Multimetallic Catalysis

16. CLASSIFICATION OF MULTIMETALLIC CATALYSIS
Multimetallic reactions can be classified by the role the two metals play in enabling a successful reaction.
Herein, we describe five types of mechanistic pathways, defined by how the metals interact with each
other:
• redox activation, when one metal transfers electron(s) (or energy) to and from a second metal;
• activation and capture, when a single metal reacts with a substrate to form a nonmetallic, reactive
intermediate, such as a radical, that another metal can trap for functionalization;
• domino multimetallic reaction, when one of the catalysts sequentially activates and rearranges a substrate
before reaction/transfer with the second catalyst;
• transmetalation, when each catalyst activates a distinct substrate, followed by a group transfer event
between the metals;
• shuttle, when a third metal transfers a substrate from one metal to another metal.

17. FUTURE OUTLOOK