1. Swollen-induced in-situ encapsulation of chiral silver catalysts in cross-linked polysiloxane elastomers: Homogeneous reaction and heterogeneous separation.
- Author
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Yin, Guan-Wu, Wu, Shi-Lu, Yan, Jun-Hao, Zhang, Peng-Fei, Yang, Meng-Meng, Li, Li, Xu, Zheng, Yang, Ke-Fang, and Xu, Li-Wen
- Subjects
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CATALYSTS , *ENCAPSULATION (Catalysis) , *ELASTOMERS , *POLYMERS , *SILOXANES , *SILICONES - Abstract
• Swollen-induced in-situ encapsulation of catalysts in cross-linked polysiloxane elastomers polymer. • Silicone rubber-based microchannel reactor was employed for asymmetric transforms. • Cross-linked polysiloxane elastomers was proved to be easily recycled by filtration or pick-up,reused by several times and exhibits excellent enantioselectivities 94–96% ees The immobilization of molecular catalysts to fabricate heterogeneous catalysts for catalytic asymmetric transformations is extremely important and has attracted great attentions. Herein we developed a simple and new strategy for the heterogenization of homogeneous molecular complexes into the cross-linked polymer. It is demonstrated for the first time that the cross-linked polysiloxane elastomers can be applied for the swollen-induced in-situ encapsulation of homogeneous catalysts with or without chiral ligands. The swollen-induced in-situ encapsulation of silver catalyst system in the cross-linked polysiloxane elastomers led to the formation of silicone rubber-based hierarchically porous that could be used in asymmetric [3+2] cycloaddition, asymmetric tandem conjugate addition−elimination reaction and oxidation of hydrosilanes to silanols. The swollen-induced in-situ encapsulation of chiral silver complex in the cross-linked polysiloxane elastomers was proved to be easily recycled by filtration or pick-up and reused by several times. The simplest heterogeneous catalysis by the strategy of swollen-induced in-situ encapsulation can be extended to the encapsulation of chiral metal catalysts into different polymeric materials for the heterogenization of homogeneous catalysis. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2021
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