Abstract
New alpha,alpha'-disubstituted amino acids with a silylated side chain have been synthesized in a racemic form. Starting from a Schiff base of glycine tertbutyl ester, a large variety of Éø,Éø'-dialkylated amino acids has been obtained, depending on the alkylating reagents. The application of a hydrosilylation methodology enabled the synthesis of the same unnatural amino acids in an enantiomerically pure form. The ability of these bulky amino acids to be incorporated into peptides by solution phase methodology has also been demonstrated, since constrained silylated dipeptides have been synthesized. These new lipophilic building blocks could be useful and innovative in the design of peptaibol analogues.