I think your first resort should be finding out if he has any learning disabilities. I have seen kids with ADD hit the wall at about 4th grade and start giving up. The grades start to go and then because they are being judged a failure everyday, their self concept and thus their attitude starts to self destruct.
If he does have something like ADD, bribery won't work because even if he is trying hard to succeed - he won't be able to without the proper help. That's why finding out what is going on is so important. You deal with disrespect and failing grades(perhaps due to family situations) one way. You deal with disrespect and failing grades due to learning disabilities in an entirely different way.
It probably would be worth your time to read up on ADD/ADHD. A book I recommend a lot of the ADHD forum is "The ADD/ ADHD Answer book," by Susan Ashley. Besides giving you lots of info on it, symptoms of it, how to deal with it - it also shows ways that the schools can help. You can find it on Amazon for around $10. A pretty good web site with info can be found here - http://www.rxlist.com/attention_deficit_hyperactivity_disorder_adhd/article.htm#tocb
Thank you for the insight. I am going to have him tested for a learning disability. However my concern is the lack of interest he shows in class. He is extremely smart and intelligent. He is really disorganized and lacks discipline. I constantly remind him about everything. He fails to assume responsility. How do you teach a young boy these skills?
Without knowing if he has a learning disability first, it's almost impossible to give advice on how to help him with these skills.
I was going to say exactly what Sandman said..very often, children with learning disabilities appear to become "unruly" and "uncaring" about school because they're so fed up with being unable to keep up with and learn the lessons at the same rate as the other students...so they give up and act out.
get that evaluation ASAP
In my opinion, (and this is from personal experience) its not his lack of interest. Its that he has learned he can't succeed no matter how hard he tries and so he has given up - which is a really sad condition. Of course, this is if he has AD/HD and isn't just a lazy kid. Get the book I recommended. It will help you teach him the correct way! Best wishes.