Chiral NHC‐Complexes with Dioxolane Backbone Heterogenized on MCM‐41. Catalytic Activity

Villaverde Cantizano, Gonzalo; Corma, Avelino; Iglesias, Marta; Sánchez, Félix

Chiral NHC‐Complexes with Dioxolane Backbone Heterogenized on MCM‐41. Catalytic Activity

Download

Chiral_NHC‐Complexes.pdf (305.56 KB)

Official URL

https://doi.org/10.1002/cctc.201100119

Publication date

2011

Authors

Villaverde Cantizano, Gonzalo

Corma, Avelino

Iglesias, Marta

Sánchez, Félix

Citations

Exportar

URI

https://hdl.handle.net/20.500.14352/98473

Abstract

Rhodium, palladium, and gold complexes of chiral (NHC)–dioxolane–amino ligands were prepared. Herein, new methods for the heterogenization of NHC-chiral complexes on porous silica supports are demonstrated for the facile recovery and recycling of these expensive catalysts. Activity, selectivity, and recyclability were investigated and compared to that of the analogous homogeneous catalysts for asymmetric hydrogenation reactions. The compounds were characterized by using a variety of methods, including solid state cross-polarization magic-angle spinning (CP MAS) 13C NMR, FT-IR spectroscopy, and elemental analysis. Heterogenized rhodium(I) and palladium(II) catalysts could be used at least four times without loss of activity or enantioselectivity. (NHC)–gold(I) complexes were easily immobilized and recycled by a treatment with benzonitrile during the washing steps between cycles. This washing maintained the activity and enantioselectivity.