Is it possible to have OSX disable WiFi when the LAN is detected.
This is to prevent bridging of networks by users and compromising security on the corporate network
If I understand your question, you're concerned that users will share their wired connection to the LAN via WiFi. There's no way to prevent that, or indeed to prevent anything at all, if they have administrator rights. If you don't trust your users, don't give them admin accounts. If you do give them admin accounts, you have no choice but to trust them.
It is more that a laptop that is usually connected to external WiFi hotspots still has WiFi active when attached to the corporate network and possibly bridging the network security (by accident or otherwise)
There are PC apps that can do this but I can't find anything for Mac