Stereoselective synthesis towards unnatural proline-based amino acids

A catalytic diastereoselective Mannich reaction promoted by chiral bifunctional urea-type organocatalysts has been developed. Treatment of N-Boc-3-ketoproline with N-Boc-aldimines under mild conditions afforded the corresponding unnatural proline based amino acid derivatives with excellent diastereo...

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Bibliographic Details
Main Authors: Makhathini, S., Das, S., Singh, T., Arvidsson, P., Kruger, H., Gunosewoyo, Hendra, Govender, T., Naicker, T.
Format: Journal Article
Published: 2016
Online Access:http://hdl.handle.net/20.500.11937/21516
Description
Summary:A catalytic diastereoselective Mannich reaction promoted by chiral bifunctional urea-type organocatalysts has been developed. Treatment of N-Boc-3-ketoproline with N-Boc-aldimines under mild conditions afforded the corresponding unnatural proline based amino acid derivatives with excellent diastereoselectivities (up to 99:1) and enantioselectivities (up to 97% ee). The relative configuration of the chiral reaction products was deduced by the comparsion of the experimentally observed ECD spectra to that obtained theorectically.