On the stereoselective hydrogenation of chiral cyclobutyl dehydro-amino acid derivatives: influence of the catalyst in the pi-facial diastereoselection

摘要

Several optically active cyclobutyl dehydro-amino acid derivatives have been hydrogenated employing Wilkinson, (S,S)-chiraphos-Rh and Et-duphos-Rh (both enantiomers) as catalysts. The use of a chiral catalyst has been revealed to be crucial for the production of saturated amino acids with high stereoselectivity from substrates in which the chiral cyclobutyl unit is separated from the double bond by a methylene group. (C) 2001 Elsevier Science Ltd. All rights reserved. [References: 13]