The trick with hot brewed coffee is to chill it as quickly as possible. The longer it stays hot the more quickly it will stale. If you want to add coffee during the brewing process, instead of adding it at the end of the boil, I would add it at the end of chilling. It shouldn't raise the temperature of the wort more than 5 degrees or so, but you'll want to account for that by chilling a little lower than you usually do.
That said, you really should be adding the coffee as close to bottling as possible. It doesn't like to age.