Skeletal Rearrangement in the ZnII-Catalyzed [4+2]-Annulation of Disubstituted N-Hydroxy Allenylamines with Nitrosoarenes to Yield Substituted 1,2-Oxazinan-3-one Derivatives

Abstract

This work reports zinc-catalyzed [4+2]-annulation reactions of disubstituted N-hydroxy allenylamines with nitrosoarenes to afford substituted 1,2-oxazinan-3-ones with a skeletal rearrangement. This annulation is applicable to a reasonable scope of allenylamines and nitrosoarenes. Our control experiments indicate that nitrosobenzene can also implement this annulation through a radical annulation path, but with poor efficiency. Zn(OTf)2or AgOTf greatly improves the efficiency of this [4+2]-annulation; the effect of these metal species is discussed in detail.