here a palladium(II)-catalyzed oxidative cyclization reaction of N-allylimines derived from methyl ketones, typically acetophenones, affording pyrrole derivatives at room temperature under oxygen atmosphere. The reaction likely proceeds through α-palladation of the imine followed by olefin migratory insertion and β-hydride elimination, thus representing a new example of aerobicdehydrogenative Heck cyclization
An efficient, noble-metal-free formal [4+2] cycloaddition reaction between ketones and imines was developed for synthesizing poly-substituted pyridines, whereby two sequential C−C bonds are formed.