High pressure promoted dearomatization of nitroarenes by [4+2] cycloadditions with silyloxydienes.

Simple nitroarenes such as nitronaphthalenes and nitroquinolines smoothly undergo dearomatizing [4+2] cycloadditions with silyloxydienes under 16 kbar. Highly functionalized 3-dimensional polycyclic adducts bearing a tetrasubstituted carbon centre at the ring junction are obtained in one step from simple raw materials. This unprecedented dearomative Diels-Alder process is performed at room temperature without any chemical promoter, illustrating the exceptional role of high pressure as a physical promoter.