Synthesis of Polycyclic Lactams and Sultams by a Cascade Ring-Closure Metathesis/Isomerization and Subsequent Radical Cyclization

Starting from readily available substrates, a new one-pot procedure has been devised to prepare polycyclic lactams and sultams. 2-Pyrrolines obtained from N,N-bisallylamides by ring-closure metathesis and subsequent isomerization promoted by ruthenium hydride complexes can undergo radical cyclization to furnish polycyclic lactams in good yields. The process was successfully conducted on bisallylsulfonamides to give the corresponding sultams.