Organic & Biomolecular Chemistry 2012-04-28

Enantioselective Reformatsky reaction of ethyl iododifluoroacetate with ketones.

Michal Fornalczyk, Kuldip Singh, Alison M Stuart

Index: Org. Biomol. Chem. 10(16) , 3332-42, (2012)

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Abstract

Two approaches have been developed for the enantioselective Reformatsky reaction of ethyl iododifluoroacetate with ketones to form a quaternary carbon centre using (1R,2S)-1-phenyl-2-(1-pyrrolidinyl)-1-propanol as the chiral ligand. Good yields and high enantioselectivities (80-91% ee) were achieved with a range of alkyl aryl ketones in a convenient one-pot protocol using ethyl iododifluoroacetate and diethylzinc to form the difluorinated Reformatsky reagent homogeneously. In the traditional two-step Reformatsky reaction using the preformed Reformatsky reagent generated from ethyl iododifluoroacetate and zinc dust, good yields and good enantioselectivities (75-84% ee) were also obtained.This journal is © The Royal Society of Chemistry 2012