Synthesis of a family of peracid-silica materials and their use as alkene epoxidation reagents

Christian A. Contreras, Patricia Anne A Ignacio-De Leon, Justin M Notestein

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Alkene epoxidation is an important process for the production of resin monomers and other chemical intermediates. The challenges of and high costs associated with purifying these reactive intermediates motivates the search for new reagents that can afford epoxides in high yields and selectivity with no soluble byproducts. Here, we synthesize a family of silica-supported peracids with variations in the peracid surface density and surface chemistry and describe their use as epoxidation reagents. Materials in this study were synthesized from either sol-gel co-condensation with cyanoalkylsilanes or by grafting of silyl esters to pre-formed silica, giving titrated peracid loadings from 0.3 to 1.5 mmol/g. At constant peracid:alkene ratios, epoxide yields increased monotonically with increasing surface density, up to 1.0 mmol/g for the highest loading materials. Mixed silica surfaces possessing both alkyl and peracid moieties gave, at similar peracid surface densities, 2-3-fold greater olefin conversion, and doubled epoxide selectivity from 45 to >95%, as compared to materials with peracids alone. Hydrophobic, mixed silane-supported peracids give unusual, high selectivity to dioxide syntheses from dienes even at low conversion, suggesting strong adsorption of reactive intermediates, which is not possible for soluble peracids. These experiments suggest tunable parameters that lead to improvements in selectivity and yields in epoxidation with these easily-handled, immobilized peracids.

Original languageEnglish
Pages (from-to)289-295
Number of pages7
JournalMicroporous and Mesoporous Materials
Volume225
DOIs
Publication statusPublished - May 1 2016

Fingerprint

epoxidation
Epoxidation
Alkenes
Silicon Dioxide
alkenes
Olefins
reagents
Epoxy Compounds
Silica
epoxy compounds
silicon dioxide
selectivity
synthesis
Silanes
Surface chemistry
Sol-gels
Byproducts
dienes
Condensation
Esters

Keywords

  • Epoxidation
  • Peroxyacid
  • Sol-gel
  • Supported reagent

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Chemistry(all)
  • Condensed Matter Physics

Cite this

Synthesis of a family of peracid-silica materials and their use as alkene epoxidation reagents. / Contreras, Christian A.; Ignacio-De Leon, Patricia Anne A; Notestein, Justin M.

In: Microporous and Mesoporous Materials, Vol. 225, 01.05.2016, p. 289-295.

Research output: Contribution to journalArticle

@article{0b22cb6e64c84259908db2899ad546d7,
title = "Synthesis of a family of peracid-silica materials and their use as alkene epoxidation reagents",
abstract = "Alkene epoxidation is an important process for the production of resin monomers and other chemical intermediates. The challenges of and high costs associated with purifying these reactive intermediates motivates the search for new reagents that can afford epoxides in high yields and selectivity with no soluble byproducts. Here, we synthesize a family of silica-supported peracids with variations in the peracid surface density and surface chemistry and describe their use as epoxidation reagents. Materials in this study were synthesized from either sol-gel co-condensation with cyanoalkylsilanes or by grafting of silyl esters to pre-formed silica, giving titrated peracid loadings from 0.3 to 1.5 mmol/g. At constant peracid:alkene ratios, epoxide yields increased monotonically with increasing surface density, up to 1.0 mmol/g for the highest loading materials. Mixed silica surfaces possessing both alkyl and peracid moieties gave, at similar peracid surface densities, 2-3-fold greater olefin conversion, and doubled epoxide selectivity from 45 to >95{\%}, as compared to materials with peracids alone. Hydrophobic, mixed silane-supported peracids give unusual, high selectivity to dioxide syntheses from dienes even at low conversion, suggesting strong adsorption of reactive intermediates, which is not possible for soluble peracids. These experiments suggest tunable parameters that lead to improvements in selectivity and yields in epoxidation with these easily-handled, immobilized peracids.",
keywords = "Epoxidation, Peroxyacid, Sol-gel, Supported reagent",
author = "Contreras, {Christian A.} and {Ignacio-De Leon}, {Patricia Anne A} and Notestein, {Justin M}",
year = "2016",
month = "5",
day = "1",
doi = "10.1016/j.micromeso.2016.01.008",
language = "English",
volume = "225",
pages = "289--295",
journal = "Microporous and Mesoporous Materials",
issn = "1387-1811",
publisher = "Elsevier",

}

TY - JOUR

T1 - Synthesis of a family of peracid-silica materials and their use as alkene epoxidation reagents

AU - Contreras, Christian A.

AU - Ignacio-De Leon, Patricia Anne A

AU - Notestein, Justin M

PY - 2016/5/1

Y1 - 2016/5/1

N2 - Alkene epoxidation is an important process for the production of resin monomers and other chemical intermediates. The challenges of and high costs associated with purifying these reactive intermediates motivates the search for new reagents that can afford epoxides in high yields and selectivity with no soluble byproducts. Here, we synthesize a family of silica-supported peracids with variations in the peracid surface density and surface chemistry and describe their use as epoxidation reagents. Materials in this study were synthesized from either sol-gel co-condensation with cyanoalkylsilanes or by grafting of silyl esters to pre-formed silica, giving titrated peracid loadings from 0.3 to 1.5 mmol/g. At constant peracid:alkene ratios, epoxide yields increased monotonically with increasing surface density, up to 1.0 mmol/g for the highest loading materials. Mixed silica surfaces possessing both alkyl and peracid moieties gave, at similar peracid surface densities, 2-3-fold greater olefin conversion, and doubled epoxide selectivity from 45 to >95%, as compared to materials with peracids alone. Hydrophobic, mixed silane-supported peracids give unusual, high selectivity to dioxide syntheses from dienes even at low conversion, suggesting strong adsorption of reactive intermediates, which is not possible for soluble peracids. These experiments suggest tunable parameters that lead to improvements in selectivity and yields in epoxidation with these easily-handled, immobilized peracids.

AB - Alkene epoxidation is an important process for the production of resin monomers and other chemical intermediates. The challenges of and high costs associated with purifying these reactive intermediates motivates the search for new reagents that can afford epoxides in high yields and selectivity with no soluble byproducts. Here, we synthesize a family of silica-supported peracids with variations in the peracid surface density and surface chemistry and describe their use as epoxidation reagents. Materials in this study were synthesized from either sol-gel co-condensation with cyanoalkylsilanes or by grafting of silyl esters to pre-formed silica, giving titrated peracid loadings from 0.3 to 1.5 mmol/g. At constant peracid:alkene ratios, epoxide yields increased monotonically with increasing surface density, up to 1.0 mmol/g for the highest loading materials. Mixed silica surfaces possessing both alkyl and peracid moieties gave, at similar peracid surface densities, 2-3-fold greater olefin conversion, and doubled epoxide selectivity from 45 to >95%, as compared to materials with peracids alone. Hydrophobic, mixed silane-supported peracids give unusual, high selectivity to dioxide syntheses from dienes even at low conversion, suggesting strong adsorption of reactive intermediates, which is not possible for soluble peracids. These experiments suggest tunable parameters that lead to improvements in selectivity and yields in epoxidation with these easily-handled, immobilized peracids.

KW - Epoxidation

KW - Peroxyacid

KW - Sol-gel

KW - Supported reagent

UR - http://www.scopus.com/inward/record.url?scp=84957559658&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84957559658&partnerID=8YFLogxK

U2 - 10.1016/j.micromeso.2016.01.008

DO - 10.1016/j.micromeso.2016.01.008

M3 - Article

VL - 225

SP - 289

EP - 295

JO - Microporous and Mesoporous Materials

JF - Microporous and Mesoporous Materials

SN - 1387-1811

ER -