Boring Emphasis
so/such (a/an)+ adj/adverb. That's such a boring city, don't go there!
Dull Result not possible
Too + adj /adv (+ to-infinitive) (not) + adj/adv + enough (+ to-infinitive/that clause). That book is too dull to study for a whole year.
Madly Cause and result
So/such (a/an) + adj/adverb + that. Penny is so madly in love with James that they have decided to elope this weekend.