Not really. Brain death means the brain does not function at all, incl initiating breathing etc. A coma is described as "just" being unable to perform voluntar

Not really. Brain death means the brain does not function at all, incl initiating breathing etc. A coma is described as "just" being unable to perform voluntary (high level) actions. So basically unresponsiveness. The usual coma patient is able to breeze on their own (sometimes with some assistance). A brain dead patient is not. One could argue that "brain dead" is a subset of "comatose", at best.