title: Exploiting aggregation to achieve phase separation in macrocyclization.
abstract: The aggregation properties of poly(ethylene glycol) (PEG) can be exploited in organic synthesis to control dilution effects. Through the use of solvent mixtures containing PEG(400) /MeOH, macrocyclization by Glaser-Hay coupling can be conducted at high concentrations. The origin of the selectivity has been studied by using surface tension measurements, UV spectroscopy, and chemical tagging and demonstrates the dependence of the yield and selectivity on the aggregation of PEG(400)  and its ability to preferentially solubilize organic substrates, resulting in a phase separation from the catalyst system.
authors.affiliation: Département de Chimie, Centre for Green Chemistry and Catalysis, Université de Montréal, CP 6128 Station Downtown, Montréal, Québec H3C 3J7, Canada.
authors.forename: Anne-Catherine
authors.initials: AC
authors.lastname: Bédard
authors.forename: Shawn K
authors.initials: SK
authors.lastname: Collins