Looking up reaction precedents without retraining the model closed most of the training-coverage gap
AspireAI community · arXiv (2610.40249)
Retrosynthesis models are trained on a specific set of chemical transformations, so a reaction type they never saw tends to break them. This work asks how far a simple retrieval step can compensate, using 2.71 million reactions and expanding only the retrieval corpus while holding model parameters fixed. For transformations excluded from training, mean Top-1 accuracy rose from 13.0 percent to 58.0 percent on a historical test set and from 4.9 percent to 23.1 percent on a temporally held-out one. For temporal coverage gaps, a model trained on records before 2017 matched or exceeded a non-retrieval model trained on records before 2025 on both test sets. Without any task-specific fine-tuning, reaction precedents improved all 14 representative general-purpose models on both test sets and on USPTO-50K, and the strongest one with precedents surpassed all eight representative specialised models. The limitation is latency and corpus dependence - the gains need a large, well-indexed precedent set.
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