Palladium-Catalyzed α-Arylation of Azlactones to Form Quaternary Amino Acid Derivatives
作者:Xiaoxiang Liu、John F. Hartwig
DOI:10.1021/ol034570q
日期:2003.5.1
of alpha-aryl-alpha-alkyl amino acid derivatives from alpha-amino acids by the arylation of azlactone derivatives is reported. Arylation of azlactones derived from alanine, valine, phenalanine, phenyl glycine, and leucine all provided good yields of the arylated product. Mechanistic studies of this reaction revealed that a stable complex containing a ligand formed by reaction of dba with the azlactone
The first catalytic hydrocarboxylation of enamides and imines with CO2 to generate valuable α,α‐disubstituted α‐amino acids is reported. Notably, excellent chemo‐ and regio‐selectivity are achieved, significantly different from previous reports on β‐carboxylation of enamides, homocoupling or reduction of imines. Moreover, this transition‐metal‐free procedure exhibits low loading of an inexpensive catalyst
photocatalytic umpolung strategy for reductive carboxylation of imines for the synthesis of α-aminoacids was disclosed. Carbon dioxide radical anion (CO2•–) generated from formate is the key single electron reductant in the reactions. An unprecedentedly broad substrate scope of imines with excellent reaction yields was obtained with carbon dioxide (CO2) and formate salt as carbon sources.