In:
Pure and Applied Chemistry, Walter de Gruyter GmbH, Vol. 84, No. 8 ( 2012-5-24), p. 1713-1727
Abstract:
Studies aimed at synthesizing surfactants from biomass-based feedstocks using Pd-catalyzed telomerization of 1,3-butadiene resulted in the development of a highly active catalyst system. A ligand screening was performed, and Pd/tris(2-methoxyphenyl)phosphine (TOMPP) was identified as the most promising catalyst. A solvent- and base-free protocol was developed, which allows efficient and selective conversion of a wide variety of polyol substrates (e.g., glycerol, diols, carbohydrates, and sugar alcohols). In the case of hemi-acetal bearing sugars, catalyst deactivation was observed and mechanistic studies showed that extensive formation of ligand-derived phosphonium species depleted the amount of available ligand. Stoichiometric coordination reactions gave insight into the phosphine alkylation mechanism and demonstrated the reversibility of the observed reaction. A simple and efficient one-pot synthesis method was developed for the preparation of [Pd((1-3,7,8η)-( E )-octa-2,7-dien-1-yl)(PR 3 )] + complexes, which are key reactive intermediates. Based on these studies, an extended telomerization mechanism is proposed, which accounts for the formation of ligand-derived phosphonium species and the reversibility of reaction pathways.
Type of Medium:
Online Resource
ISSN:
1365-3075
,
0033-4545
DOI:
10.1351/PAC-CON-11-12-06
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
2012
detail.hit.zdb_id:
2022101-0
