Linked bis(β-diketiminato) yttrium and lanthanum complexes as catalysts in asymmetric hydroamination/cyclization of aminoalkenes (AHA)
作者:Daniela V. Vitanova、Frank Hampel、Kai C. Hultzsch
DOI:10.1016/j.jorganchem.2010.09.051
日期:2011.1
the steric bulk of the aryl substituents, which is an indication for highly steric encumbered catalytic species. The complexes displayed good to moderate catalytic activity in the hydroamination/cyclization of aminoalkenes depending on the steric hindrance around the metal center. The sterically most demanding diisopropylphenyl-substituted complex (R,R)-5 displayed significantly higher enantioselectivities
基于乙烯桥联的配体[C 2 H 4(BDI DClP)2 ] H 2 [DClP = 2,6-Cl 2 C 6 H 3 ]和环己基桥联的双(β-二酮亚胺基)稀土金属配合物配体[Cy(BDI Ar)2 ] H 2 [Ar = PMP(= p -MeOC 6 H 4),Mes(= 2,4,6-Me 3 C 6 H 2),DIPP(= 2,6- i Pr 2 C 6 H 3)]是通过胺消除从[Ln N(SiMe 3)2 } 3 ](Ln = La,Y)制备的。三种环己基桥接的复合物[(R,R)-Cy(BDI Mes)2 } YN(SiMe 3)2 ]((R,R)-3),[(R,R)-Cy(BDI Mes)2 } LaN(SiMe 3)2 ]((R,R)-4)和[(R,R)-Cy(BDI DIPP)2 } LaN(SiMe 3)2 ]((R,R)-5)是对映体纯的。对3和4的外消旋体的X