Carbenylative amination with N-tosylhydrazones.
A Pd-catalyzed reaction of vinyl iodides and N-tosylhydrazones that assembles η(3)-allyl ligands through carbene insertion is demonstrated. Intramolecular trapping with nitrogen nucleophiles generates good yields of cinnamyl and pentadienyl amines like those found in alkaloid natural products. Carbenylative amination was the key reaction to complete the synthesis of the alkaloid caulophyllumine B. Migratory insertion was biased to provide allylamines with optical purity up to 64% ee, but in a lower yield.