A one-pot protocol for the synthesis of 5-(1,2,3,4-tetrahydroisoquinolin-1-yl)-1,3,4-oxadiazoles via DEAD-mediated oxidative Ugi/aza-Wittig reaction has been developed. The reaction of (N-isocyanimine)triphenylphosphorane, carboxylic acids, and N-aryl-1,2,3,4-tetrahydroisoquinolines produced polysubstituted 5-(1,2,3,4-tetrahydroisoquinolin-1-yl)-1,3,4-oxadiazoles directly in good yields in the presence of DEAD as an oxidant.
Key words
oxidative Ugi reaction - aza-Wittig reaction - 1,3,4-oxadiazole - 1,2,3,4-tetrahydroisoquinoline - (
N-isocyanimine)triphenylphosphorane