| Organolanthanide complexes of the type (η5-Me 5C5)2LnCH(TMS)2 (Ln = La, Sm), [Me 2Si(η5-Me4C5)2]SmCH(TMS) 2, and [Me2Si(η5-Me4C 5)(tBuN)]LnE(TMS)2 (Ln = Sm, Y, Yb, Lu; E = N, CH) serve as efficient precatalysts for intramolecular hydroamination/cyclization of amine-tethered unactivated 1,2-disubstituted alkenes to afford the corresponding mono- and disubstituted pyrrolidines and piperidines. In addition, chiral C1-symmetric organolanthanide catalysts of the type Me 2Si(OHF)(CpR*)LnN(TMS)2 (OHF = η5-octahydrofluorenyl; Cp = η5-C5H3; R* = (−)menthyl; Ln = Sm, Y), and Me2Si(η5-Me4C 5)(CpR*)SmN(TMS)2 (Cp = η5-H3C 5; R* = (−)-menthyl) mediate asymmetric intramolecular hydroamination/cyclization of amines bearing internal olefins and afford chiral 2-substituted piperidine and pyrrolidine in enantioselectivities as high as 68% at 60°C. Thermolysis of (η5-Me5C5)2LaCH(TMS) 2 in cyclohexane-d12 at 120°C rapidly releases CH 2(SiMe3)2, and leads to possible formation of fulvene (η6-Me4C5CH2-) species. Catalytically active lanthanide-amido complexes (η5-Me 5C5)2La-(NHR)(NH2R)n and [Me2Si(η5-Me4C5)( tBuN)]Sm-(NHR)(NH2R)n are found to be thermally robust species.; Organolanthanide-catalyzed regioselective intermolecular hydroamination of alkynes R′C≡CMe (R′ = SiMe 3, C6H5, Me), alkenes RCH=CH2 (R = SiMe3, CH3CH2CH2), butadiene, vinylarenes ArCH=CH2 (Ar = phenyl, 4-methylbenzene, naphthyl, 4-fluorobenzene, 4-trifluoromethylbenzene, 4-methoxybenzene, 4dimethylaminobenzene, 4-methylthiobenzene), di/divinylarenes, and methylenecyclopropanes with primary amines R ″NH2 (R″ = n-propyl, n-butyl, i-butyl, phenyl, 4-methylphenyl, 4-dimethylaminophenyl) affords the corresponding amines and imines. For vinylarenes, intermolecular hydroamination with n-propylamine affords anti-Markovnikov addition product, β-phenylethylamine. In addition, hydroamination of divinylarenes provides a concise synthesis of tetrahydroisoquinoline structures via coupled intermolecular hydroamination/subsequent intramolecular cyclohydroamination sequences. Intermolecular hydroamination of methylenecyclopropane proceeds via highly regioselective exo-methylene C=C insertion into Ln-N bonds, followed by regioselective cyclopropane ring-opening to afford the corresponding imine. |
