I think we all already know that "officially" award tickets are not upgradeable. So what probably would be most helpful to the OP is suggestion(s) of how to do it by other means.

On more than one occasion I have been the recipient of other FlyerTalkers' kindness who have used their industry insight (including gate agents) to op-up me into C or F. And when I can, I do the same for other FTers.

Now, if you're on the 12:30pm flight from ORD to PVG, then it looks like United has 3 more Business seats left for sale, while coach is wide open. If UA doesn't overbook its Business (meaning that those are actually 3 still-empty seats), then you still have a chance.

Good luck. and welcome to FlyerTalk.
BCH