In English, there are professors who have the title Chair, which comes from the exact same Latin root (cathedra) that the Spanish Cátedra comes from. (Sometimes the administrative department head is also called the Chair, but that's a different meaning of the word.)
However, I don't believe that there is any specific word to identify a course taught by such a chair. I also asked my husband, who is a university professor, and he's never heard of this term either.
I think this is because, although catedrático and chair have the same linguistic origin, they are actually different in meaning (at least as "chair" is used in North Amercia). According to that Spanish Wikipedia article I linked, a Spanish catedrático advances to that position by passing a series of requirements, much like getting tenure, only more prestigious. A North American endowed chair, on the other hand, exists because some wealthy donor has decided to donate money (an endowment) for the purpose of funding a specific academic niche. Usually the chair is named after both the donor (or someone they want to honor) and the field of study. The "William H. Gates Sr. Chair of Population and Public Health" at Johns Hopkins University would be an example: it's endowed by Bill Gates and named after his father.
Because a endowed chair is somewhat prestigious, one can assume that most people who manage to be hired into them are good in their field, but it's not at all necessary that they are the best in their department. If the only endowed chair in a computer science department is in artificial intelligence (because that's what the wealthy donor wanted to fund), then it doesn't matter how brilliant a quantum computing professor is, he'll never be appointed to that chair.
And that's why there's no word in English for "a course taught by a chair." There's nothing especially attractive about taking a course that's taught by someone who was fortunate enough to specialize in an area that a wealthy donor decided to fund.