Yes, you read that right. There is now a free structure searching program available to search all chemical compounds in Wikipedia. It was developed by Peter Ertl, Luc Patiny, Thomas Sander, Christian Rufener and Michaël Zasso. See the article in the Journal of Cheminformatics, DOI: /10.1186/s13321-015-0061-y (Wikipedia structure browser: Substructure and similarity searching of molecules from Wikipedia)
Try it here: http://www.cheminfo.org/wikipedia
Additionally, structure searching is now available in Web of Science. On the search page, click on the drop down next to Basic Search, and select Structure Search. This will take you to a drawing editor similar to ones you are already using. You will need to have Java installed, and download the Accelrys JDraw Applet. For instructions on using the drawing editor and to download the applet, see this page, available through the Help menu on Web of Science; or feel free to contact me at email@example.com.