Reaxys is a product by Elsevier which catalogs and indexes chemical substances and reactions. It is free for CSHL researchers. Reaxys also allows you to plan chemical reactions to achieve desired chemical endpoints. Reaxys contains information from the scientific literature and chemical suppliers as well as patent information.
CAS SciFindern is a source for authoritatively identifying a chemical substance and its related chemical structures, chemical names, regulatory information, and properties, including CAS Registry Numbers®, reaction schemes, step-by-step experimental procedures, detailed conditions, and product yields.