Supporting InformationGeneral. Microanalyses were performed by Galbraith Laboratories or Atlantic Microlab. The actual charges of substrates and reagents are given below. The molar amounts are calculated based on the assays of the materials. Similarly, yields are calculated based on assay corrected moles of substrates and products. Proton ( 1 H) nuclear magnetic resonance (NMR) spectra were recorded on either a Unity Inova Varian 300 MHz or Unity Inova Varian 400 MHz spectrometer. 1 H NMR descriptions are reported as: s (singlet), d (doublet), t (triplet), q (quartet), m (multiplet) or br (broad).Carbon ( 13 C) nuclear magnetic resonance (NMR) spectra were recorded on either a Unity Inova Varian 300 or Unity Inova Varian 400 spectrometer at 75 MHz and 100 MHz, respectively.Melting points were determined using a Laboratory Devises Mel-Temp Instrument equipped with a Fluke 51 Thermocouple. Thin-layer chromatography was performed on EM Science 0.25 nm Silica Gel 60, glass-backed plates with F 254 indicator. UV light was employed for visualization. Flash chromatography was performed on Universal Scientific 0-63 mesh Silica Gel. Liquid chromatography and mass spectrum analysis were performed on an Agilent 1100 Series LC/MSD model number G1946D equipped with an APCI ionization source and photodiiode array. Chiral HPLC method for separation of
[reaction: see text] A practical, large-scale synthesis of a beta-amino ester 1 was developed. A chiral imine derived from (S)-phenylglycinol and 3-trimethylsilylpropanal was coupled with the Reformatsky reagent 3 with high diastereoselectivity (de > 98%) to give (SS)-4a as the major isomer. The amino alcohol residue of the coupling product 4 was oxidatively cleaved with sodium periodate in the presence of methylamine. An unusual selective oxidative cleavage of the (SS)-isomer was observed and the imine 6 was obtained with ee > 99% while the (RS)-4b isomer was not cleaved. Reaction with p-toluenesulfonic acid monohydrate allowed for the hydrolysis of the imine and the isolation of the amine as its salt. The title compound 1 was then obtained by transesterification, desilylation, and hydrochloride salt formation in a one-pot process. The method was successfully applied toward the synthesis of a wide variety of beta-amino esters.
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