I'm going to keep my toxic friend away from our mutual friends
Why do you want to isolate him from your other friends?
I don't want them to get infected by his negativity.
It is good to want to protect your friends from harm. It might be better to end your friendship with the toxic person if they continue to harm your relationships.
I can handle my toxic friend. I just wanna keep my other friends safe.
Toxic relationships can be damaging to your life and your mental health, and sometimes you don't even realize to what extent until you end the relationship. If you know that your friend is toxic, it would be a good idea to end the friendship and focus on healthier relationships.