https://doi.org/10.1351/goldbook.M03923
The term is applied to characterize the relative tendency of a group to participate in a @R05194@. In nucleophilic rearrangements ( @M03920@ 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.