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 New Class of Non-<i>C</i><sub>2</sub>-Symmetric Ligands for Oxidative and Redox-Neutral Palladium-Catalyzed Asymmetric Allylic Alkylations of 1,3-Diketones
作者:Barry M. Trost、Etienne J. Donckele、David A. Thaisrivongs、Maksim Osipov、James T. Masters
DOI:10.1021/jacs.5b00786
日期:2015.2.25
We report the discovery, synthesis, and application of a new class of non-C-2-symmetric phosphoramidite ligands derived from pyroglutamic acid for use in both oxidative and redox-neutral palladium-catalyzed asymmetric allylic alkylations of 1,3-diketones. The resulting chiral products are typically obtained in high yield with good to excellent levels of enantioselectivity.
Flexible and Modular Syntheses of Enantiopure 5-cis-Substituted Prolinamines from l-Pyroglutamic Acid
A wide range (25 examples) of 5-cis-substituted prolinamines is prepared in five to ten steps starting from cheap L-pyroglutamic acid. Three routes, differing mainly in the order of introduction of the substituents at the 5-cis position, the pyrrolidine nitrogen atom, and the exocyclic amino function, are successfully developed.