(4,4‐Difluoro‐4‐bora‐3a,4a,‐diaza‐s‐indacen‐3‐yl)acetaldehyde: Synthesis and chemical properties

Abstract magnified image A reaction of 3,5‐dimethylborondipyrromethene 3 with the DMF dimethylacetal gives rise to monoenamine 4 . The latter is converted to the corresponding aldehyde 5 . A considerable contribution of the enolic form of the aldehyde allows preparing numerous 3‐vinyl substituted borondipyrromethenes and some heterocyclic derivatives. A reaction of the aldehyde 5 with tertiary aliphatic amines and the consecutive Hofmann‐type decomposition of the intermediary quaternary salt give rise to the corresponding dialkylaminovinyl derivatives. J. Heterocyclic Chem., (2009).