Could you elaborate? There's Azure AD, or you could do yourself a massive favor and not use AD at all. And like... why would you want AD and an intranet but not someone to manage it at all? Recipe for disaster.
The simplest solution to this problem, by far, is to just avoid it entirely. Don't have an intranet. Don't manage AD. Just don't do those things.
Pick an identity provider, pick a file sharing service, pick a video chat service, and set up SSO for them. It's 0 maintenance, far safer, and far easier to use.
