Catalytic Enantioselective Synthesis of Functionalized Cyclopropanes from α‐Substituted Allyl Sulfones with Donor‐Acceptor or Diacceptor Diazo Reagents

The catalytic asymmetric synthesis of highly functionalized cyclopropanes from α‐substituted allyl sulfones and silanes is reported. The reaction, using α‐aryl diazoacetates or diacceptor diazo reagents, catalyzed by a chiral rhodium complex (Rh2((S)‐BTPCP)4), furnished the corresponding cyclopropanes in moderate to high yields (27–97 %), high diastereoselectivities (68 : 32 to 20 : 1 d.r.) and moderate to excellent ee (40–99 %). This methodology offers a privileged access to an underexplored class of enantioenriched cyclopropanes with a high level of functionality, an asset for further post‐functionalization and their incorporation into more complex structure. Small rings: The catalytic asymmetric synthesis of highly functionalized cyclopropanes from α‐substituted allyl sulfones is described. The methodology, using α‐aryl diazoacetates or diacceptor diazo reagents, catalyzed by a chiral rhodium complex furnished the corresponding cyclopropanes in high yields with excellent diastereo‐ and enatioselectivities.