Software that can predict organic reaction products is hotly pursued because of its obvious potential in pharmaceutical industry. However, stereochemistry is not included in the vast majority of the previous efforts, although its control is often the most challenging and interesting part of organic reactions. This is not an accidental omission but maybe an inherent problem of molecule representations in computers. The molecule representation methods (strings, tables, matrix etc.) used by programmers differ from those of chemists, which may be the reason that the software can not fully take advantage of the knowledge and wisdoms of chemists.
VirtualChemist is an organic reaction software suite focusing on stereochemistry. A new design (
https://www.jstage.jst.go.jp/article/jccjie/8/0/8_2021-0050/_article ) was proposed to translate molecule Lewis structure to machine readable format data. The knowledge and wisdoms of chemists, if being Lewis structure based, can now be digitized. Using Lewis formula as the only user input, which can be either an existing molecule or a molecule unknown yet,
(1).
Stereoisomer can identify all the stereocenters and give VSEPR 3D geometries of all the stereoisomers for the molecules with tetrahedral carbon atoms, and the molecules with carbon-carbon (nitrogen) double bonds, as well as allene derivatives with chiral axles.. With sigma-bond rotation and "Flip" functionality, it can present conformational isomers.
(2).
Tautomer can simulate the practice of chemists writing acid/base catalyzed tautomerization and enumerate all the tautomers. An algorithm to check duplicates was implemented by comparing the Lewis structures of newly generated tautomers and those of previously generated ones.
(3).
Reaction Stereochemistry is a mechanism-based organic reaction software focusing on stereochemistry, It can track molecular 3D configuration changes in every elementary reaction step. Not a single stereoisomer is missed.
The demo videos show the basic graphic user interfaces of the software and its basic functionalities.
There are two versions of the software, free version and commercial version. The table below summarizes the major differences between the two versions.
| | Stereoisomer | Reaction Stereochemistry | Tautomer |
| | Free | Commercial | Free | Commercial | Free | Commercial |
| conformational isomer | only one | one or more | only one | one or more | | |
| configurational isomer | only one | one or more | only one | one or more | | |
| reaction set | | | | | only one | one or more |
| 3D rotation | no | yes | no | yes | yes | yes |
| user enter Lewis Formula | no | yes | no | yes | no | yes |
The free version is listed in Microsoft Store, and can be downloaded at https://apps.microsoft.com/search/publisher?name=RO+Software+Ltd&hl=en-us&gl=CA. If interested in the commercial version, please contact the developer.