If she is trying to exclude him, that really isn't fair to him and the issue needs to be addressed with her. However, if she gives him as much attention as she gives the other students and he simply cannot accept that, perhaps his reaction should be investigated further by the school psychologist. Developing your son's interests in and outside of school may be helpful in giving him a sense of purpose. Find out his strengths and try to build on those. Piano lessons may help fulfill this need.
Some bookstores have book clubs for young readers.
There are ways to meet a child's needs creatively outside of the classroom that may be quite effective. Encourage your son's teacher to develop a partnership with you to design an appropriate educational plan for your child. This may include enrichment within and outside the classroom. Because behavior appears to be an issue, perhaps a behavior management plan is in order, too. Work with the teacher to set some goals for your child and offer your support to help achieve them.