AIarXiv

Ranked by formulaVerdict: Notable

Solvent: Long-Horizon Reasoning for Multi-Step Retrosynthesis

Multi-step retrosynthesis requires recursively transforming a target molecule through successive reaction steps into purchasable building blocks, and recent work has begun to draw on large language model (LLM)…

By Wang, Wang, Feng +7

Score████░░░░░░3.8

Key numbers

  • 2.1× performance boost from RL
  • 61.86% across four benchmarks

Caveats

  • Preprint; not yet peer reviewed.

VerdictWorth a reader's time today.

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Abstract

Multi-step retrosynthesis requires recursively transforming a target molecule through successive reaction steps into purchasable building blocks, and recent work has begun to draw on large language model (LLM) reasoning to tackle the task. In its latest evolution, LLM reasoning has entered the long-horizon regime: models pursue objectives across interdependent steps, interact with environments, and adapt to feedback. This shift has markedly advanced LLM capabilities, as illustrated by breakthroughs in AI-driven mathematical research. At this frontier, we introduce Solvent, an 8B LLM that successfully extends long-horizon reasoning to multi-step retrosynthesis. Through a two-round post-training curriculum, Solvent learns to interleave iterative synthesis planning, external availability verification, and adaptive route revision. Experiments show that, following a 2.1× performance boost from RL, Solvent scores 61.86% across four benchmarks, surpassing mid-scale language models and prior search-based retrosynthesis systems, and rivaling frontier trillion-parameter LLMs.

Yifei Wang, Botian Wang, Jiangtao Feng, Xinbo Zhang, Yawen Ouyang, Yixin Wu, Lihao Wang, Xiaoqing Zheng, Xuanjing Huang, Hao Zhou

The editor's rubric

Heuristic review

Leverage4 / 5
A general-purpose tool used across several fields (Adam, ResNet, LoRA, next-generation sequencing).
24% of this desk’s rubric
Magnitude4 / 5
A qualitative jump: a capability or regime that did not exist before.
18% of this desk’s rubric
Evidence3 / 5
Solid: multiple benchmarks or cohorts, ablations, fair baselines, released code or data.
14% of this desk’s rubric
Novelty2 / 5
A new combination of known ideas.
16% of this desk’s rubric
Trajectory3 / 5
A clear path to scale.
18% of this desk’s rubric
Stakes2 / 5
Benefits a professional community (practitioners, clinicians, engineers).
10% of this desk’s rubric

Editor’s rationale

Heuristic triage from title and abstract text only, not a reading of the paper. Cues found: method (we propose); breadth (many tasks); gains (x-fold, relative gain, outperforms); verification (multiple benchmarks, code released); scale (scalable); stakes (general AI).

How the score was computed

rank-2026-10-18

Score████░░░░░░3.8

Score = 10 × (65% × adjusted merit / 10 + 25% × attention + 10% × freshness)

Desks place stronger verdicts first, then use this score to order work within the same verdict.

Merit
6.3 / 10
Weighted rubric, evidence-gated.
Adjusted merit
5.1 / 10
Shrunk toward the desk prior by editor confidence (46%).
Attention
0%
Citations, upvotes, points, mentions.
Freshness
46%
Half-life decay since publication.

No attention signals recorded yet.

The record

  • Reviewed by heuristic-v10 on Oct 26, 2026, 03:46 UTC. Paper type: method.
  • Categories: cs.AI
  • BRIEF, No.6 in the Artificial Intelligence edition of October 26, 2026.