Enantioselective Synthesis of Indanes with a Quaternary Stereocenter via Diastereoselective C(sp3)–H Functionalization

A practical synthesis of enantioenriched indane derivatives with quaternary stereocenters was developed via sequential enantioselective reduction and C–H functionalization. Good to excellent enantioselectivity could be achieved by either the CuH-catalyzed asymmetric reduction or the Corey–Bakshi–Shibata (CBS) reduction of indanone derivatives. The subsequent diastereospecific and regioselective rhodium-catalyzed silylation of the methyl C–H bond led to indane derivatives with quaternary centers. This strategy was further applied in syntheses of (nor)illudalane and botryane sesquiterpenoids.