Palladium-Catalyzed\n(3+2) and (4+2) Cycloaddition\nReactions of Sulfamidate Imine-Derived Azadienes: Synthesis of Spirocyclic\nPyrrolidines and Tetrahydroquinolines

Diastereoselective Pd-catalyzed (3+2) and (4+2) cycloaddition\nreactions\nof sulfamidate imine-derived 1-azadienes with zwitterionic N-dipoles\nderived from 1-tosyl-2-vinylaziridine and 4-vinylbenzoxazinone have\nbeen developed. These reactions provide highly functionalized azaspirocycles\nfeaturing three contiguous stereocenters. The sulfonyl imine moiety\nof the cycloadducts can be fully reduced to access valuable β-amino\nalcohols.