Rolf Appel (25 February 1921 – 30 January 2012) was an inorganic chemist who worked in the area of organophosphorus chemistry.
During this time, he was influenced by G. O. Schenck and Karl Ziegler.
Several years after the war, he entered the graduate program at Heidelberg, receiving his PhD for studies on disulfur trioxide at age 30.
[1][2] He was appointed in 1962 to the University of Bonn, where he remained throughout his career.
Among his many innovations at Bonn, he developed the Appel reaction.