Enantioenriched BCP Benzylamine Synthesis via Metal Hydride Hydrogen Atom Transfer/Sulfinimine Addition to [1.1.1]Propellane

The stereoselective synthesis of bicyclo[1.1.1]­pentane (BCP) benzylamine derivatives from [1.1.1]­propellane and mesityl sulfinimines via metal hydride hydrogen atom transfer (MH HAT) is reported. Medicinally relevant heterocyclic BCP methanamines are prepared with high diastereoselectivity. The strategic impact of the method is demonstrated via the streamlined synthesis of the BCP analogue of a key levocetirizine intermediate. Mechanistic evidence for a competitive H2 evolution pathway and the importance of controlled silane addition during reaction initiation are disclosed.