Asymmetric Intramolecular Rauhut–Currier Reaction and Its Desymmetric Version via Double Thiol/Phase-Transfer Catalysis

An
asymmetric intramolecular Rauhut–Currier reaction of
linear bis­(enones) has been achieved via double activation catalysis
of thiols and phase transfer substances, furnishing both enantioenriched
cyclohexene and cyclopentene derivatives (up to 95% ee). Furthermore,
the desymmetric version of prochiral substrates was developed under
similar catalysis, producing the frameworks bearing an additional
tertiary or even quaternary stereogenic center with moderate to excellent
diastereo- and enantioselectivity (up to 95% ee, >19:1 dr).