The logP or Octanol/Water partition coefficient is now available for nearly all the molecules on Cheméo.
The logP is predicted using the Wildman and Crippen method: "Prediction of Physicochemical Parameters by Atomic Contributions". You can download the full text as pdf, if this is not available anymore, just ask me and I will send it to you.
For the moment, this method is not available in the online prediction too but it will be added in the future.
Here is a search for molecules with a logP between 2.3 and 2.7.