title: Chiral aggregates and asymmetric induction of the reduction of prochiral ketones.
abstract: The aim of this work was to establish structure-reactivity relationships between chiral aggregates (micelles, vesicles, and "pseudo-micelles" of amphiphilic dendrimers) and asymmetric induction. In water, micelles or vesicles formed with sugar-headed surfactants gave less than 10% ee in the reduction of prochiral ketones by NaBH(4), in contrast with dendrimers bearing the same types of sugar moieties, which gave more than 50% ee under the same reaction conditions. Moreover, in the presence of neoglycodendrimers in THF we have been able to improve reduction of prochiral ketones to give very high stereoselectivity, near 100% in many cases. Comparison of these results suggests that to improve high stereoselectivity it is necessary to work with rigid, well-organized colloidal objects. Copyright 2000 Wiley-Liss, Inc.
authors.affiliation: Laboratoire des IMRCP, UMR CNRS 5623, Université Paul Sabatier, Toulouse, France.
authors.initials: I
authors.lastname: Rico-Lattes
authors.initials: A
authors.lastname: Schmitzer
authors.initials: E
authors.lastname: Perez
authors.initials: A
authors.lastname: Lattes