2 year old going on 5 and their thuggish behaviour

I have a 2 year old boy who is very advanced in speech and his understanding of things in general although we hav one major problem!! He is very overpowering to other children and will hit and push of others mainly his own age when in certain settings such as toddler groups and nursery. I also have a 6year old boy who was the polar oppposite and very well behaved. My little one is so funny and loves making people laugh but his hitting and bossiness with other kids is so embarrassing. I discipline him with the naughty spot (which he dislikes) and he always says a heart felt apologie but still does it again 5 mins later! It does only seem to be a certain places he behaves like this and other times he shares really well with other children and is always very polite! Please help xx