Journal article
Site-Isolation and Recycling of PdCl2 using PDMS Thimbles
Journal of organic chemistry, Vol.74(13), pp.4834-4840
2009
DOI: 10.1021/jo900570y
Abstract
Macroscopic thimbles composed of polydimethylsiloxane (PDMS) were used to site-isolate PdCl2 from the products of Wacker−Tsuji oxidations and Pd-mediated homocouplings. The reactions were completed on the interior of hollow thimbles, and the organic products were isolated by their selective flux to the exterior of the thimbles. Although organic molecules had high flux through the walls of the thimbles, PdCl2 remained encapsulated as a result of its polar structure that rendered it insoluble in PDMS. In two examples, less than 0.002% of the PdCl2 added to the interior of the thimble partitioned to the exterior; thus, over 99.998% remained encapsulated on the interior of the thimble. Because it was encapsulated, this catalyst was readily recycled five times for the Wacker−Tsuji oxidation of styrene. A sequential reaction was also completed where p-methylstyrene was oxidized to 4′-methyl-acetophenone by PdCl2 on the interior of a thimble and then fluxed to the exterior to react with phenylmagnesium bromide to yield 1-phenyl-1-p-tolyl-ethanol. This method site-isolated PdCl2 catalysts without requiring them to be rendered heterogeneous, the addition of exogenous ligands, or any modifications to the catalyst. The catalyst was site-isolated by affecting its environment rather than by altering its ligand structure.
Details
- Title: Subtitle
- Site-Isolation and Recycling of PdCl2 using PDMS Thimbles
- Creators
- A Lee Miller II - Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United StatesNed B Bowden - Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
- Resource Type
- Journal article
- Publication Details
- Journal of organic chemistry, Vol.74(13), pp.4834-4840
- Publisher
- American Chemical Society
- DOI
- 10.1021/jo900570y
- ISSN
- 0022-3263
- eISSN
- 1520-6904
- Language
- English
- Date published
- 2009
- Academic Unit
- Chemistry
- Record Identifier
- 9984216561702771
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