This is a very difficult situation and one I see often. To try and give you some insight from a teachers perspective I have found there are two kinds of children like this. The first kind misbehaves when bored because the work doesn't stretch and challenge them enough (I would have been exactly the same as a child) , the second kind considers themselves too clever to do any work regardless of how difficult it is and the main issue is attitude.
If children in the first group aren't applying themselves, or are misbehaving in the lessons then I would put that fully onto the teacher - they need to differentiate sufficiently to engage that child. I have taught children like this, and as soon as you give them something that is difficult and interesting they are fully engaged and 99% of behaviour and attitude problems are gone.
Children in the second group are a lot more difficult to deal with, and regardless of how differentiated or difficult the work is they consider themselves above it (and usually above the teacher in terms of intelligence.) I often think it is a maturity thing, something I think 99% will grow out of, however they need to grow out of it before it impacts important stages, like GCSEs. I can give you an example, I have a pupil, let's call her B, she is incredibly bright, she could leave her GCSEs with three A in my subject with no problem. However she literally does nothing all lesson, and worse than that she stops others doing work who aren't as clever. She has work given to her every lesson which is incredibly difficult and challenging, yet she will find every opportunity possible to disrupt others instead of trying it. Every question is met with a silly smart comment, every two minutes she is out of her seat to put something in the bin or to borrow something off someone else, this is just so she can chat. At the start of the year she was getting straight As in her tests, at parents evening I spoke to her and her parents about this attitude problem and said she needs to be pushing for those A because she is more than capable. However now we have got to the end of the year, we are further into the course and going over the more difficult concepts and she is still displaying this I can do everything without any work attitude, yet her grades are slipping. In an observed lesson with myself, which was rated as outstanding, her response to an understanding check at the start of the lesson was that she could do everything already. When she was quizzed about it by the observer she couldn't, but still had a smart response/comment about it rather than engaging with the fact that actually she needed to get her head down and get on with it. Now some people may point the finger of blame at me as a teacher, I should be making sure that she is working and getting everything done, and yes I should. But I have 29 other pupils in that class who are also my responsibility and I view it like this, do I spent most of the lesson on the one child who clearly considers themselves above anything we do, constantly asking them to get on and get things done. Or do I focus my attention on the 29 other pupils who maybe aren't as naturally bright, but are working their socks off to get better grades. I have 60 minutes in a lesson, that's two minutes per pupil, obviously it doesn't work out like that but if every five minutes I am returning to the same pupil who just can't be bothered it really isn't fair.
Like I said a lot of pupils grow out of this attitude, I do believe it is a maturity thing and from my perspective it seems to be more common in boys than girls. I don't doubt that there are some teachers out there who make the attitude and situation worse with their lack of effort (I.e. suitable differentiation) and I definitely had teachers in school that I considered stupid and had little respect for. However again I think it is a maturity thing where this opinion is applied to all teachers, rather than the ones where maybe there is an issue that needs to be addressed. Teenagers are a very complex group, I have a year 8 form, so they are just hitting that crazy hormone stage and at least once a week we end up in a discussion about teachers shouting and being unfair, and why can't we shout back at the teachers etc. Then we get into the whole thing of, well does every teacher shout at you - no, have I ever shouted at you - no, have I ever asked you to do something during registration in an unreasonable way - no, so are all teachers nasty and mean and horrible so it's fine for you lot to be rude and talk over all of them - no etc etc.
I'm not sure this has helped much, I think I have just waffled on a little bit too much. What I am trying to say is if your child falls into the first category then go in and speak to the teachers about how they can challenge him more in lessons. If he is in the secondary category then hopefully it is an age/maturity thing and he will grow out of it soon.