Intramolecular Hydroamination/Cyclization of Aminoalkenes Catalyzed by Ln[N(SiMe3)2]3 Grafted onto Periodic Mesoporous Silicas
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- 作者：Erwan Le Roux ; Yucang Liang ; Michael P. Storz ; Reiner Anwander
- 刊名：Journal of the American Chemical Society
- 出版年：2010
- 出版时间：November 24, 2010
- 年：2010
- 卷：132
- 期：46
- 页码：16368-16371
- 全文大小：188K
- 年卷期：v.132,no.46(November 24, 2010)
- ISSN：1520-5126
文摘
Homoleptic rare-earth metal silylamide complexes Ln[N(SiMe3)2]3 (Ln = Y, La, Nd) were grafted onto a series of partially dehydroxylated periodic mesoporous silica (PMS) supports, SBA-15-500 (dp = 7.9 nm), SBA-15LP-500 (dp = 16.6 nm), and MCM-41-500 (dp = 4.1 nm). The hybrid materials Ln[N(SiMe3)2]3@PMS efficiently catalyze the intramolecular hydroamination/cyclization reaction of 2,2-dimethyl-4-penten-1-amine. Under the prevailing slurry conditions the metal size (Y > La > Nd), the pore size, and the particle morphology affect the catalytic performance. Material Y[N(SiMe3)2]3@SBA-15LP-500 displayed the highest activity (TOF = up to 420 h−1 at 60 °C), with the extralarge pores minimizing restrictive product inhibition and substrate diffusion effects. The catalytic activity of Y[N(SiMe3)2]3@SBA-15LP-500 is found to be much higher than that of the molecular counterpart (TOF = up to 54 h−1), and its recyclability is demonstrated.