Reaxys Predictive Retrosynthesis powered by Pending.AI release notes for April 2025

This release focuses on improving the retrosynthesis predictions by updating the model and on enhancing the user experience by automating the re-launch of jobs with extended parameters, reducing instances of no results found.

Pending.AI Updated Model and Service 

The updated Pending.AI model leverages the latest Reaxys reaction data, now incorporating information from patents and journals up to June 2024, compared to the previous model, which was based on data only until December 2023. This enhancement has increased the training set by approximately 0.5 million reactions, resulting in an additional 10,000 reaction rules.

Reaxys predictive retrosynthesis powered by Pending.AI automation of no results 

In the event of no results, the default settings are automatically changed to extended parameters to increase the likelihood of obtaining a predicted synthesis route. In summary, the extended parameters will be modified as follows:  

• Diversity of routes parameter is minimized which results in more routes returned (A)
• The processing time is changed to Extended (B)
• All building block libraries are selected (C)

In case the extended parameters fail to predict a synthesis route, then a ‘Last step only’ is automatically run giving the users some ideas about where they could potentially start breaking the target molecule. The results of original and extended projects are grouped for easier navigation.  All projects within a group can be made visible by clicking “Expand” button (D).