Controlling Diastereoselectivity in Dearomatizing Diels-Alder Reactions of Nitroarenes with 2-Trimethylsilyloxycyclohexadiene.

Dearomative Diels-Alder cycloadditions between nitroarenes and 2-trimethylsilyloxycyclohexadiene are carried out under high pressure at room temperature in the absence of any chemical promoter. Reactions are performed with different arenes, including the highly aromatic naphthalenes and quinolines. They lead to 3D-scaffolds with exquisite exo-diastereoselectivity. The exo approach is characterized by lower distortion of the substrates in a late TS and by more favorable orbital interactions presumably between the nitro group and the dienic part, explaining the stereoselectivity.