Hyperconjugation not steric repulsion leads to the staggered s ...

而不是老教科书提到效应。

As steric hindrance of the aryl amine decreased and nucleophilicity increased, occurrence of the transfor-mation reaction increased and herbicidal activity of the product decreased.

芳胺空小,亲强,副反应容易发生,产物除草活低。