He was particularly known for championing the work of contemporary Expressionists in Cologne and Berlin before the War, especially Paul Klee, Otto Dix, and Vasily Kandinsky.
[2] He founded the publishing house Kairos Verlag, which produced the magazine Der Strom, and represented the work of Hans Hansen, and the drawings of Max Ernst and others.
The Museum of Fine Arts, Boston, which ended up with the painting, filed a successful lawsuit against the Reichel heirs claiming title.
[5] In 2017 the heirs of Kurt Grawi made a restitution claim for a painting by Franz Marc that had passed through the Nierendorf Gallery in 1939.
[7][8] Also in 2017 the heirs of the Jewish businessman and collector Eugen Moritz Buchthal recovered nine works from the Kupferstichkabinett Berlin which had purchased them through the Nierendorf Gallery.