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Acceleration of Batch-type Heterogeneous Ligand-free Suzuki-Miyaura Reactions with Polymer Composite Supported Pd Catalyst

An efficient and recyclable palladium (II) catalyst supported on a double-structured amphiphilic polymer composite was reported previously containing a polymer hydrogel within macroporous polystyrene (PS) microspheres. However, some critical questions have been unaddressed. First, the catalyst accel...

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Autores principales: Wang, Mian, Xue, Han, Ju, Fei, Yang, Haijie
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5539156/
https://www.ncbi.nlm.nih.gov/pubmed/28765564
http://dx.doi.org/10.1038/s41598-017-06499-z
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author Wang, Mian
Xue, Han
Ju, Fei
Yang, Haijie
author_facet Wang, Mian
Xue, Han
Ju, Fei
Yang, Haijie
author_sort Wang, Mian
collection PubMed
description An efficient and recyclable palladium (II) catalyst supported on a double-structured amphiphilic polymer composite was reported previously containing a polymer hydrogel within macroporous polystyrene (PS) microspheres. However, some critical questions have been unaddressed. First, the catalyst accelerated the heterogeneous ligand-free batch Suzuki-Miyaura reaction in a H(2)O/EtOH mixture solution at room temperature in the presence of air, which could be ascribed to the “on-water” effect taking place at the interface of the aqueous–organic and basic-aqueous phases created by sodium carbonate in H(2)O/EtOH. To this acceleration, the double-structured amphiphilic polymer composite can also contribute by providing hydrogels inside the macroporous PS that served as a microreactor. This microreactor allowed the reactions to quickly proceed across the two immiscible (i.e. aqueous-organic and basic-aqueous) phases. Moreover, hydrogels containing hydroxyl groups can also serve as phase-transfer catalysts (PTC) to promote the Suzuki reaction. Second, the deactivated catalyst recovered its initial catalytic activity after overnight air exposure. This observation indicates the importance of oxygen in the activation/deactivation of Pd metals, as determined by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) measurements which revealed different Pd oxidation states with various morphologies before and after Suzuki reactions.
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spelling pubmed-55391562017-08-07 Acceleration of Batch-type Heterogeneous Ligand-free Suzuki-Miyaura Reactions with Polymer Composite Supported Pd Catalyst Wang, Mian Xue, Han Ju, Fei Yang, Haijie Sci Rep Article An efficient and recyclable palladium (II) catalyst supported on a double-structured amphiphilic polymer composite was reported previously containing a polymer hydrogel within macroporous polystyrene (PS) microspheres. However, some critical questions have been unaddressed. First, the catalyst accelerated the heterogeneous ligand-free batch Suzuki-Miyaura reaction in a H(2)O/EtOH mixture solution at room temperature in the presence of air, which could be ascribed to the “on-water” effect taking place at the interface of the aqueous–organic and basic-aqueous phases created by sodium carbonate in H(2)O/EtOH. To this acceleration, the double-structured amphiphilic polymer composite can also contribute by providing hydrogels inside the macroporous PS that served as a microreactor. This microreactor allowed the reactions to quickly proceed across the two immiscible (i.e. aqueous-organic and basic-aqueous) phases. Moreover, hydrogels containing hydroxyl groups can also serve as phase-transfer catalysts (PTC) to promote the Suzuki reaction. Second, the deactivated catalyst recovered its initial catalytic activity after overnight air exposure. This observation indicates the importance of oxygen in the activation/deactivation of Pd metals, as determined by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) measurements which revealed different Pd oxidation states with various morphologies before and after Suzuki reactions. Nature Publishing Group UK 2017-08-01 /pmc/articles/PMC5539156/ /pubmed/28765564 http://dx.doi.org/10.1038/s41598-017-06499-z Text en © The Author(s) 2017 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Wang, Mian
Xue, Han
Ju, Fei
Yang, Haijie
Acceleration of Batch-type Heterogeneous Ligand-free Suzuki-Miyaura Reactions with Polymer Composite Supported Pd Catalyst
title Acceleration of Batch-type Heterogeneous Ligand-free Suzuki-Miyaura Reactions with Polymer Composite Supported Pd Catalyst
title_full Acceleration of Batch-type Heterogeneous Ligand-free Suzuki-Miyaura Reactions with Polymer Composite Supported Pd Catalyst
title_fullStr Acceleration of Batch-type Heterogeneous Ligand-free Suzuki-Miyaura Reactions with Polymer Composite Supported Pd Catalyst
title_full_unstemmed Acceleration of Batch-type Heterogeneous Ligand-free Suzuki-Miyaura Reactions with Polymer Composite Supported Pd Catalyst
title_short Acceleration of Batch-type Heterogeneous Ligand-free Suzuki-Miyaura Reactions with Polymer Composite Supported Pd Catalyst
title_sort acceleration of batch-type heterogeneous ligand-free suzuki-miyaura reactions with polymer composite supported pd catalyst
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5539156/
https://www.ncbi.nlm.nih.gov/pubmed/28765564
http://dx.doi.org/10.1038/s41598-017-06499-z
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