New Nickel-Catalyzed Reaction Simplifies Synthesis of Complex Drug Building Blocks
"Simplifying assembly of these structures changes how chemists approach synthesis."
— Senior author Phil Baran
A team of chemists at Scripps Research has developed a novel nickel-catalyzed cross-coupling reaction that allows carbon fragments to be joined together while preserving three-dimensional molecular geometry. The method represents a significant advance for pharmaceutical chemistry, as it simplifies the construction of complex, chiral molecules that are difficult to make with conventional techniques.
Key Advancements
- High Selectivity and Yields: The reaction achieves 80–96% enantiospecificity and 40–90% yields across pharmaceutically relevant substrates, including piperidine and pyrrolidine scaffolds.
- Simple, Standard Conditions: No chiral ligands or specialized additives are required, and the reaction runs under standard lab conditions.
- Gram-Scale Scalability: The process scales to gram quantities and tolerates functional groups such as free amines, olefins, heterocycles, and aryl bromides.
How It Works
The reaction couples a sulfonyl hydrazide with an alkyl halide via short-lived carbon radicals. A "caged radical rebound" mechanism on the nickel center preserves chirality throughout the process.
Dramatic Improvement in Synthetic Efficiency
One piperidine building block that previously required seven steps was produced in a single coupling step at 60% yield with 95% stereoretention—a dramatic improvement in synthetic efficiency.
Publication Details
The research was published in Science.