On the one hand, there has been a fair amount of literature claiming that Bohr is Kantian. On the other hand, some contemporary philosophers see Bohr’s association with Kant as yet one more strike against the validity of his ideas.
But the simple fact is that Bohr was way downstream from Kant. Between Kant and Bohr, we have Fichte and Hegel, not to speak of Herbart, Trendelenburg, and Lotze. Bohr’s philosophy teacher, Harald Høffding, was a good historian, and he knew about all of these movements, and he was critical of all of them. (Høffding was like the Larry Sklar of early 20th century philosophy: he understood all philosophical schools, and sided with none of them.)
Danish philosophers of the late nineteenth century had indeed incorporated parts of Kant’s view. They were definitely “post critical” in the sense that they weren’t speculative metaphysicians. But these Danish philosophers believed that they had gotten beyond “Kritiken”, as they called it. Here is Rasmus Nielsen in 1880 (five years before B.’s birth):
Vor Videns Ufuldkommenhed skal, siger ‘Kritiken’, vise sig deri , at vi kun erkjende Tingenes Love, men ikke deres Væsen; selvfølgelig have vi intet Begreb om en fuldkommen Viden. (Almindelig Videnskabslære i Grundtræk, p 65)
He then goes on to say that ‘Kritiken’ made a mistake.