ArcCatalog Pane: switch off base map.
Hello Lothar,
I think your question may need a bit of clarification to get the answer you desire. Including screen shots may make your situation easier to grasp.
The Catalog pane doesn't dictate what is displayed in the map, rather it grants access to folder connections, services, database connections, toolboxes, etc. Under the Map heading you can add a basemap here, which will add a basemap frame to the project (refer to image below). If you want to remove this frame you can right click it in the Catalog pane and click delete, or click the X button on the tab denoting the frame. This is the closest thing I could find to what your describing (Basemap in Catalog Pane) however I suspect it is not the answer you're looking for. If you could clarify on your situation further perhaps I can get you the answers you need!
I hope this helps,
Lukas
