Electrophilic substitution on disubstituted benzene rings is governed by directing effects.
the verdict
COMMON KNOWLEDGE
no citation needed for this one
refutedsupported
the weight of evidence
no sources on either side
The retrieved literature covers various specialized catalytic C-H functionalization and organometallic reactions rather than standard organic chemistry textbook principles. However, the governing role of directing effects in electrophilic substitution on substituted benzene rings is a foundational and widely established principle in organic chemistry.