We are sad to inform you that University Professor Ronald Breslow passed away last night. Ronald was a titanic figure in the field of chemistry and made a deep impact on Columbia University. Arriving at Columbia in 1956, Breslow made wide ranging fundamental and practical contributions which include his work on the cyclopropenyl cation, the mechanism of the vitamin B1 catalyzed benzoin condensation and the founding of the field of biomimetic chemistry. Breslow was a member of the National Academy of Sciences and the winner of the National Medal of Science, the Preistley Medal and the Welch Award, among other honors. He mentored over one hundred students and postdocs, many of whom have gone on to distinguished careers in chemistry and other fields. He was the recipient of the Mark Van Doren Award and Columbia’s Great Teacher Award for his teaching. In 1981 he wrote the influential “Breslow Report” that paved the way for Columbia’s transition to becoming a co-educational institution. As a scientist, mentor, colleague and citizen of the university, Ronald Breslow was irreplaceable and will be sorely missed.