Oppolzer-Type Intramolecular Diels–Alder Cycloadditions via Isomerizations of Allenamides
摘要:
A new approach to Oppolzer's Intramolecular Dlels-Alder cycloaddition (IMDA) through gamma-isomerlzation of readily available N-tethered allenamides is described. These IMDA reactions are carried out in tandem with the allenamide isomerization or 1,3-H shift, leading to complex nitrogen heterocycles in a highly stereoselective manner.
A new catalyst system for intramolecular olefin aminoacetoxylation is described. In contrast to previously reported palladium- and copper-catalyzed systems, the conditions outlined in this communication favor piperdine formation with terminal olefin substrates and induce cyclization with traditionally less reactive disubstituted olefins.