Skip to main content

Reaxys: Searching by Reaction

Basic Reaction Seaching

Very Similar to performing a structure search. See Using the structure editor 

Or choose the Create struture/Reactions tab on the main Reaxys search screen

Searching for a Reaction by Drawing Both Reactant and Product

If you have a particular reaction in mind and wish to know how to achieve it, you can draw a complete reaction, including both reactant and product structures.

  • Draw the substances that you wish to participate in your reaction.
  • You can draw one or more reactants and one or more products, but be sure to put all of the reactants on one side of the screen and all of the products on the other.
  • Select the reaction arrow tool , and click and drag to form an arrow between the reactants and products.

  • When you have chosen the reactant and the product, indicated by the blue numbers select the Transfer to query button under the editor to search for the reaction
  • The Query will appear as; 
  • When the query is finished searching it is up to the user to chose the substance structure, as drawn, similar, or as reactions
  • In this example we are searching for reactions

Mapping Reactants to Products

If you wish the chemistry to occur at a particular place in the structure, you can map atoms from reactant to product.  This tells the database that the atom marked in the reactant corresponds to the marked atom in the product and allows you to set reaction centers (and avoid unwanted reaction centers).

  • Draw your reaction, as described above.
  • Use the  too to select first area you wish to map from a reactant to a product
  • The areas will be indicated by a small blue number, 1 maps to 1, 2 to 2 etc. 


  • Right-click on the atom in the reactant that you wish to map to an atom in the product, and click on the Atom properties option.
  • Unlock the Map option, and choose a number to represent the mapped atom.
  • Click Ok.
  • Repeat the procedure for the corresponding atom in the product.

Searching for a Reaction by Drawing Either a Reactant or a Product

To create a substance or break a particular bond without having a complete reaction

  • Draw only a reactant or a product and specify reaction centers, as well as bonds to be broken or formed.
  • Drawing the reactant or product in which you are interested.
  • Either draw a reaction arrow to the right or left of the structure (to designate it a reactant or product), or transfer your query to the search interface and select the option to search for your structure in a particular reaction role.
  • Available roles are Product, Starting Material, Any Role, or Reagent/Catalyst.
  • Set substructure and other options from the main search screen.

Setting Bonds to Be Broken or Formed

  • Right click on the bond that you wish to make. 
  • Select Bond Properties and Reacting center , and choose make or break - ||
  • This will locate reactions that form the bond if the structure drawn is designated a product and that break the bond if the structure is designated starting material. 
  • The bond will be designated with a hash mark.
  • Now, right-click on the atoms whose stereochemistry you wish to retain.
  • Select Atom properties and Enhanced stereo, and choose Absolute

Adding Text to a Reaction Query

Use the Query Builder to combine text and structure searching

  • You can start by adding structural information to your query, clicking on the Structure option at the top of the screen.
  • There are two methods of adding reaction conditions to the search: Forms option, and Fields in the Query Builder.
  • The asterisk * is the truncation symbol in Reaxys.

Forms Search:

The form-based search is done from the Query Builder option in the main menu

The search Properties bar at the top allow the user to search within all of the forms and fields options.  


Fields Search: The fielded search makes available all possible reaction fields. It can be used in the same way that you searched for properties,

  • Clicking and dragging on a field adds it to the search box
  • Each field has a relation pull-down menu and a magnifier, used to navigate the index for this search field.
  • Select from the menu, and then click the magnifier to browse the index of that field.
  • Use the Transfer button to transfer one or more index entries to the search box.
  • For numeric fields, the optimal method of populating the field is simply to type the value or range onto the search line.
  • group fields with parentheses by dragging and dropping the second field on top of the first.