o-Quinodimethane Atropisomers: Enantioselective Synthesis and Stereospecific Transformation

o-Quinodimethanes have remarkable utility as reactive inter-mediates in Diels-Alder reactions, enabling significantly accelerated routes to complex polycyclic compounds. The discovery of different discrete pre-cursors to thermally generate o-quinodimethanes thereby greatly augmented their availability and versatility. However, due to the required high tem-peratures and the immense reactivity of o-quino-di-methanes, stereo-selectivity to afford iso-merically defined products still constitutes a critical challenge. Herein, we describe the accessibility of atropisomeric o-quino-dimethanes, the enantio-selective synthesis of their precursors, their remarkable configurational stability and the stereo-specific transformation by the benz-annulation of dienophiles. A catalyst-stereo-controlled [2+2+2] cyclo-addition, the generation of o-quino-dimethane atrop-isomers and ensuing stereo-specific Diels-Alder reactions enabled enantio-selectivities through these transient inter-mediates with of up to 96:4 e.r.