That’s a BINGO!
“It was manufactured by two German companies: Tesch and Stabenow (which was based in Hamburg) and Degesch (which was based in Dessau). Zyklon“
- from: https://www.britannica.com/science/Zyklon-B
However, according to DuckDuckGo’s AI:
BASF Chemicals in WW2
During World War II, BASF, as part of the conglomerate IG Farben, manufactured a variety of chemicals, including Zyklon B, which was used in the gas chambers of Nazi concentration camps. IG Farben also extensively employed forced and slave labor during this period.
Such as the plant outside Dachau.
Do you have any solid reference to Rockefeller participation in that activity? I've found lots of noise about it, but nothing I would use as a citation.