o‐Quinodimethane Atropisomers: Enantioselective Synthesis and Stereospecific Transformation

o‐Quinodimethanes have remarkable utility as reactive intermediates in Diels–Alder reactions, enabling significantly accelerated routes to complex polycyclic compounds. The discovery of different discrete precursors to thermally generate o‐quinodimethanes thereby greatly augmented their availability and versatility. However, due to the required high temperatures and the immense reactivity of o‐quinodimethanes, stereoselectivity to afford isomerically defined products still constitutes a critical challenge. Herein, we describe the accessibility of atropisomeric o‐quinodimethanes, the enantioselective synthesis of their precursors, their remarkable configurational stability and the stereospecific transformation by the benzannulation of dienophiles. A catalyst‐stereocontrolled [2+2+2] cycloaddition, the generation of o‐quinodimethane atropisomers and ensuing stereospecific Diels–Alder reactions enabled enantioselectivities through these transient intermediates with of up to 96 : 4 e.r.