Advise on 7yr old

So my son is in 1st grade and he won’t listen to the teacher and has become somewhat disrespectful to her and other authority figures. He won’t sit still and do his work and is often sent to the office because of this. The teacher said he doesn’t do his work, he’s disruptive to other students, touches things he’s not suppose to and just doesn’t listen. I’ve tried everything at home to get him to listen from time out to spanking and taking his toys away and making him sit in the kitchen all day.It’s getting to a point that I’m just so frustrated. He doesn’t pull any of this at home except for an attitude here and there. He said he doesn’t know why he does it. And that school is boring. I’m at my wits end. I don’t know what to do anymore I’m so tired of the bad reports from school. Am I missing something? I feel like such a bad mom like why is he acting like this. I do a lot with me kids and I don’t want to yell at him everyday because he can’t get his act together at school. Anyone experience this with their child? And did they grow out of it?