1. introduction: dbu – the “universal player” in the chemistry industry in the chemistry world, 1,8-diazabicycloundene (1,8-diazabicyclo[5.4.0]undec-7-ene, dbu for short) is known for its unique molecular structure and excellent catalytic properties. it is like a skilled magician, showing amazing abilities in different chemistry. dbu is not only an efficient alkaline catalyst, but also plays an...