You know ～のに for an adversative conjunction(e.g. 許さなかったのに), right? When this に is attached to the presumptive ～う/よう, the nominalizer の is not used. (Probably this is a remnant of its classical form; e.g. 許さなかったに).
By the way, at the back of my mind is a thought that this ～う/よう + に can be used with another meaning too, depending on context, though I can't remember what the meaning actually is. Is this right, or am I imagining it? (I mean ～う/よう as in the verb form; I'm not talking about the other ように meaning "in order to", "so that" or similar.)