There are a few ways to do this, it all depends on if you're needing it done at the individual course level as if you're the instructor or if you're an Admin and looking for it to be done globally over a particular term.
Locally you can review the gradebook. If you're needing it to be in a excel formatted report you can export gradebook.
If you're needing this done at a global level and have admin privileges, you can go into the account level reports and run the grades export report.
In either case once exported you can filter by grades, so that only those with D's and lower are still on the report.
Hope one of these is what you're looking for. Let us know if you have any further questions.