"Widening the roof": Synthesis and characterization of new chiral C₁-symmetric octahydrofluorenyl organolanthanide catalysts and their implementation in the stereoselective cyclizations of aminoalkenes and phosphinoalkenes

New chiral C₁-symmetric organolanthanide catalysts of the type Me₂Si(OHF)(CpR*)LnN-(TMS)₂ (OHF = η⁵-octahydrofluoreny]; Cp = η⁵-C₅H₃; R* = (-)-menthyl; Ln = Sm, Y, Lu; TMS = SiMe₃) have been synthesized, characterized, and implemented in the enantioselective and diastereoselective cyclizations of aminoalkenes and phosphinoalkenes. Me₂Si(OHF)(CpR*)LnCl₂ ^-Li(DME)₂ ⁺ catalyst precursors can be prepared in up to ∼90% diastereomeric purity and then converted into the corresponding amido catalysts, which can be isolated in ∼100% diastereomeric purity after recrystallization. The catalyst (S)-Me₂Si(OHF)(CpR*)YN(TMS)₂ has been crystallographically characterized. The activity of these catalysts for the hydroamination/cyclization of aminoalkenes and for the hydrophosphination/cyclization of phosphinoalkenes is described. Enantioselectivites as high as 67% are obtained in hydroamination, and diastereoselectivities of as high as 96% are obtained in hydrophosphination.