“Widening the Roof”: Synthesis and Characterization of New Chiral <i>C</i>₁-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-octahydrofluorenyl; 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.