What you said
I would start with a circle time session every morning and after lunch. This would help with turn-taking and his sense of belonging, and help him to realise that everyone has a voice. You can introduce rules in these sessions, such as making sure that only one person speaks at a time.
The expert view
This sounds like hard work. There is a safety issue here. You need to be ready to intervene as soon as he starts trying to dominate and have a removal strategy ready to roll if he responds badly.
Any attempt to compromise with this pupil and meet him halfway could have several damaging effects. For a start, the pupil learns that sometimes he can get away with behaving in a way that won't assist his integration into mainstream communities.
As far as possible this behaviour needs to be deterred. It's going to be a key skill throughout his life, and a potential deal-breaker in every other social context. If he wants any life other than one of isolation and fringe existence, he needs adults to draw lines and boundaries, and then electrify them.
Also, the other pupils will see the dominance and feel that they have similar rights to rule the roost through aggression.
Keep standing firm. Have others in the classroom to assist you. Have a safe place the pupil can be removed to, to teach him that participation in the group is conditional to compliance with group rules.
Tom Bennett is author of The Behaviour Guru and Not Quite a Teacher. His latest book, Teacher, is out now, published by Continuum. Post your questions at www.tes.co.ukbehaviour.