Silylcupration of (R)-2,2-Dimethyl-3-(tert-butoxycarbonyl)-4-ethynyloxazolidine: A Stereoselective Approach to the Synthesis of gamma-Silylated Saturated and Unsaturated alfa-Amino Acids

Enantioselective synthesis of ç-silylated amino acids is reported, using a four-step procedure based on the silylcupration of ethynyloxazolidine 2. Silylcuprates 6a-c are highlighted as useful reagents to be employed with enantiomerically enriched substrates. Vinylsilanes 5 are easily prepared and highlighted as useful intermediates to yield the final compounds after reduction, opening of the oxazolidine ring, and oxidation. Moreover, â,ç-unsaturated amino acids are obtained as very interesting vinylglycine derivatives. The capability of silicon-containing amino acids to be incorporated into dipeptides is also shown