Actually, it's not very often to have an opportunity to use curved glass in real projects. It's quite expensive. But it is possible to make in real world, so it should be possible in Revit.
And here is a solution.
Make a wall type which has glass material and a sweep for transom, then use it for curtain wall panel.
I think it's one of well known tricks, but for those who don't know yet..
You can download the file above to save your time