title: Enantioselective Reformatsky reaction of ethyl iododifluoroacetate with ketones.
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.
authors.affiliation: Department of Chemistry, University of Leicester, Leicester, LE1 7RH, UK.
authors.forename: Michal
authors.initials: M
authors.lastname: Fornalczyk
authors.forename: Kuldip
authors.initials: K
authors.lastname: Singh
authors.forename: Alison M
authors.initials: AM
authors.lastname: Stuart
mesh_terms: D000433:1-Propanol / Q000737:chemistry*; D005463:Fluoroacetates / Q000737:chemistry*; D054879:Halogenation; D007455:Iodine / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D008024:Ligands; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D005463:Fluoroacetates; D007659:Ketones; D008024:Ligands; D009942:Organometallic Compounds; D007455:Iodine; D000433:1-Propanol; C454811:diethylzinc