Development of ProPhenol Ligands for the Diastereo- and Enantioselective Synthesis of β-Hydroxy-α-amino Esters
作者:Barry M. Trost、Frédéric Miege
DOI:10.1021/ja4129394
日期:2014.2.26
aldol reaction between glycine Schiff bases and aldehydes is reported. The design and synthesis of new ProPhenol ligands bearing 2,5-trans-disubstituted pyrrolidines was essential for the success of this process. The transformation operates at room temperature and affords syn β-hydroxy-α-amino esters in high yields with good to excellent levels of diastereo- and enantioselectivity.
A highly convenient way to perform the synthesis of alkynes from aldehydes is reported. The procedure utilizes a new in situ preparation of dimethyldiazomethylphosphonate. As a consequence a commercially available reagentcan now be used, circumventing a disadvantage of earlier protocols. The easy one-pot procedure avoids the use of strong bases, low temperatures and inert gas techniques.