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

而不是科书提到位阻效应。

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.

芳胺空位阻小,亲核性强,副反应发生,产物除草活性低。