Two Iodide Samarium Caused By Intramolecular Ketone Imide And Coupling Reaction And The Synthetic Beta Hydroxy - Alpha Amino Acid Derivatives

Optically active vicinal amino alcohol moiety is one of the most important structures in the organic synthesis. It is component not only in a vast group of naturally occurring molecules with special physiological activity as well as a key pharmacophore used in therapeutical agents, but also in a variety of catalysts and chiral ligands employed in stereoslective catalytic reactions. We have made in-depth study in SmI2-promoted intramolecular asymmetric pinacol-type ketone-tert-butane sulfinyl imine reductive coupling. We employed the trans-1,2-amino alcohol made from the SmI2-promoted asymmetric pinacol-type aldehyde-t-BS imine reductive coupling as the starting molecule to get the oxazoline that could be used as the key intermediate for the stereoselective synthesis of marine natural product salinosporamide A and its analogues.1、We have achieved an asymmetric intramolecular ketone-tert-butanesulfinyl (t-BS) inine pinacol-type reductive coupling promoted by SmI2. For both aryl and alkyl ketones, tran-1,2-amino alcohols were formed predominantly in excellent er and high dr. The stereochemical outcome provided evidence for a radical mechanism rather than the anion one. A series of catalysts for the asymmetric addition of ZnEt2 to aldehyde could be easily made from the tran-1,2-amino alcohols.2、(4R,5S)-2-(4-Methoxyphenyl)-4-methoxycarbonyl-5-isopropyloxazoline has been achieved from the tran-1,2-amino alcohols made by SmI2-promoted asymmetric aldehyde-t-BS imine pinacol-type reductive coupling. All of the four isomers of oxazoline could be achieved by the invertion of the hydroxyl. The oxazoline could be used as the key intermediate for the stereoselective synthesis of marine natural product salinosporamide A and its analogues.