Complex sentence: Leloir fled to the United States, where he assumed the position of associate professor in the Department of Pharmacology at Washington University in St. Louis, collaborating with Carl Cori and Gerti Cori and David E. Green at Columbia University.
Split into simpler sentences: Leloir fled to the United States, where he assumed the position of associate professor in the Department of Pharmacology at the University of Washington. He would also collaborate with Carl Cori in his St. Louis laboratory, and David E. Green at Columbia University.