Strategy-first synthesis planning for complex natural products

Designing synthesis routes for complex natural products is a highly creative, expert-level chemistry task that existing algorithmic tools struggle with, since they rely on catalogued reactions unsuited to novel, densely functionalized molecules. SynthEx, an LLM-based agentic framework, proposes and critiques multiple synthesis strategies, producing routes that expert chemists rated comparably to published human-designed syntheses. This has direct applications in pharmaceutical and chemical research, potentially accelerating drug discovery and natural product synthesis. The accompanying SynthAtlas database, covering over a thousand natural products, could serve as a shared resource for chemists tackling molecules lacking established literature routes. Paper: https://arxiv.org/abs/2608.07454