Tips and Tricks Chemistry. November 2005. Chemical Abstracts Service, CAS. CAS... we are scientists, creating and delivering the most complete and effective digital information environment for scientific research and discovery CAS is a self-sustaining division of the American Chemical Society
Tips and TricksChemistry
These answers will have the R-stereoisomers pictured either with the bond into the plane or out of the plane. The author must have provided complete configuration of the stereo node.
These answers will have the S-stereoisomers pictured either with the bond into the plane or out of the plane. It is also called the “meso” compound of our structure.
These answers will have the stereochemistry defined relative to another chiral center. The stereochemistry could be shown as R,S or S,R being identical for relative stereoisomers. Relative stereo answers can be useful for structure searches with multiple chiral centers.
These answers do not have the desired stereochemistry at the node we searched, but there is stereochemistry elsewhere in the molecule. In this case it is the Z double bond geometry. If we had searched a compound with R,R bonds, we would also see the R,S and S,R answers in this set.
These answers will be completely flat structures (or racemic mixtures) with no other stereochemistry in the structure that was searched. Some compounds with stereochemistry in the name may still be found in this set.
The 109 compounds with a score of ≥ 99 are the same as the 135 exact compounds minus the 26 tautomers
Unique answer for substructure search
Unique answer for similarity search
X = any
You may define an R-group as the VAP node; you may define multiple VAP nodes to the same ring system
Substance class or the type of study can be selected using the additional options before the search
Makes a distinction between C and Ak and Cb
Select option to refine your search
Halogen attachments are in addition to the X drawn at a variable position
Cannot analyze a node that is part of a repeating group.
Compounds may have additional halogen substitution on the phenyl ring, so numbers may be higher
Conventional structure match exactly
Closely assoc. tautomers have 1 bond shifted or created
Loosely assoc. tautomers have bigger variation
Make a selection to remove unwanted answers
This compound is considered a close tautomer, because the second double bond in the ring, could also be drawn as a keto substituent, which would have matched the query.
Option to analyze only the shape, the shape and atoms, the shape, atoms and bonds or rings that have at least one atom in common with the query structure
Replaced the specific phenyl with a generic Cb node. One X is drawn; second optional halogen is defined as R2=H,X. The tool “lock substitution” prevents additional substituents
= Same as Get References
= View 3D (Accelrys software)
= Commercial suppliers
= Search exact compound in
a reaction explore
= Regulatory information
Could work very well for reactions in water or reactions with a specific catalyst
Leads to 871 reactions from 258 documents
Records from 1907-1966 are not associated to any roles
Not all publications in Chemical Abstracts are selected for CASREACT !! (only 258 out of 480 with reaction indexing)
We are interested in compounds with a ring 10-30 atoms
SciFinder didn’t remember the original search at this point
Substance viewer features
Non-reacting role allows for searching reactions “in the presence of” a group
Information from patents and journals
Single step and
multi-step reactions; click the microscope for intermediate reaction steps
Scroll down for all steps; the mouse wheel is now enabled for power-scrolling
Get only one sample reaction per document
Hypertext link to other query hit reactions from that document
Click on a substance for more info
Reactions will search the compound itself as a reaction participant
Retrieves new reactions with this substance as the reaction product
Compare to 8 documents from
our reaction search !!
Tips and TricksChemistry