Synthesis of [1,2,3]‐Triazolo[5,1‐a]‐isoquinolines through TBAF‐Promoted Cascade Reactions

Abstract A tetrabutylammonium fluoride (TBAF)‐promoted detosylation cyclization cascade was developed for the synthesis of [1,2,3]‐triazolo[5,1‐ a ]‐isoquinolines. Most of the products were obtained in excellent yields under mild conditions. Valuable halogen‐substituted [1,2,3]‐triazolo[5,1‐ a ]‐isoquinolines could also be synthesized with a slight modification of the reaction conditions. Functionalized isoquinolines were obtained smoothly by denitrogenative reactions. The control experiments showed that this transformation was facilitated by TBAF and the water contained in the commercially obtained reagent. Deuterium labeling products could also be obtained easily in high yield.