The term is applied to characterize the relative tendency of a group to participate
in a
rearrangement. In nucleophilic rearrangements (
migration to an electron-deficient centre), the migratory aptitude of a group is loosely related
to its capacity to stabilize a partial positive charge, but exceptions are known,
and the position of hydrogen in the series is often unpredictable.
Source:
PAC, 1994, 66, 1077
(Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994))
on page 1141