To filter undesirable functional group in hit/lead identification

Dear Friends,


Can anyone  kindly assist me in hit/lead identification, in which i wish to know  what are the undesirable functional groups should be filtered out?

kindly provide any reference/article/list of functional groups that are undesirable for hit and lead identification.

Thank you very much and proper citation will be done on the reference provided.
If there is any know protocol to do so, i would be very much appreciated.

Mai