Problem with autumn blaze red Maple
It is difficult to diagnose diseases of plants without actually seeing them first-hand, however it appears that your tree has some sort of stem canker. There is not a lot you can do about it in terms of helping the tree other than relieving any stress factors that may make it more difficult for the tree to recover. You might lightly water it during dry periods, and give it a SMALL amount of some balanced fertilizer mixture (without any herbicides in it). If you wish, you could trim out the dead branches, but do so only sparingly as some of the branches may resprout foliage again if the tree recovers. Whether it recovers is very hard to say....it doesn't look promising in the photos at this point. Good luck.