Using Microenvironmental Effects to Increase Loading and Stereoselectivity for Polymer Bound NaBH4 Reagents.
Year: 2004
Type: article
Abstract: Past studies have illustrated that the microenvironment of the functional groups attached to polymer-bound reagents and catalysts plays a major role in their reactivity.This study investigated the effect that concentrating stereogenic centers within a polymer matrix had on the reduction of acetophenone.Both crosslinked polystyrenes and crosslinked polyurethanes were functionalized using chiral appendages derived from 5gluconolactone and used as supports for sodium borohydride.The results of the reduction reactions indicated that as the number of stereogenic centers increased at the linking point on the polymer, the % enantiomeric excess of the alcohols produced during the reaction also increased from 13 % enantiomeric excess to 54 % enantiomeric excess.Overall, the results of this study suggest that asymmetric pockets were formed within the polymer matrix when polar functional groups containing chiral appendages were concentrated within a non-polar polymer.
Author: James R. Blanton
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
Funder: Citadel Foundation
OpenAlex ID: W13070217