Divergent Enantioselective Synthesis of (Nor)illudalane Sesquiterpenes via Pd-Catalyzed Asymmetric C(sp)-H Activation.

A divergent enantioselective synthesis of (nor)illudalane sesquiterpenes was designed by using a Pd-catalyzed asymmetric C(sp)-H arylation as a key step to control the isolated, highly symmetric quaternary stereocenter of the target molecules. A matched combination of chiral substrate and catalyst proved optimal to reach good levels of stereoselectivity. This approach enabled the synthesis of three (nor)illudalanes, including ( S)-deliquinone and ( S)-russujaponol F, which are synthesized for the first time in enantioenriched form.