Enantioselective synthesis of β-amino acids based on BINAP—ruthenium(II) catalyzed hydrogenation
摘要:
BINAP-Ru(II) catalyzed hydrogenation of beta-substituted (E)-beta-(acylamino)acrylic acids allows efficient enantioselective synthesis of beta-amino acids. The Z double bond isomers which possess an intramolecular hydrogen bond between amide and ester groups are more reactive but are hydrogenated with poor enantioselectivity. BINAP-Rh(I) complexes afford only moderate stereoselectivity with the opposite sense of enantioselection.
Six-membered bis(azaphosphorinane), readily available ligand for highly enantioselective asymmetric hydrogenations
作者:Yongjun Yan、Xumu Zhang
DOI:10.1016/j.tetlet.2006.01.003
日期:2006.3
A new six-membered bis(azaphosphorinane) ligand has been readily prepared starting from an inexpensive chiral epoxide; excellent enantioselectivities (up to over 99% ee) have been achieved in the Rh-catalyzed asymmetric hydrogenations of β-dehydroamino acid derivatives and α-arylenamides.
bidentate phospholane and phosphinite ligands based on a benzothiophene scaffold. The ligand functions in the bidentate ligands can be introduced independently and consecutively. A bis-phospolane ligand as well as its rhodium complex have been characterized by crystal-structure determinations. The bis-phospholane ligands were tested in the catalysed asymmetric homogeneous hydrogenation of dehydroamino
Highly Efficient Synthesis of Chiral β-Amino Acid Derivatives via Asymmetric Hydrogenation
作者:Wenjun Tang、Xumu Zhang
DOI:10.1021/ol026935x
日期:2002.11.1
The Rh-TangPhos complex is an efficient hydrogenation catalyst for making chiral beta-amino acid derivatives. With the Rh-TangPhos system, high enantioselectivities (up to 99.6%) and turnover numbers have been obtained in the hydrogenation of E/Z isomeric mixtures of both beta-alkyl and beta-aryl beta-(acylamino)acrylates. [reaction: see text]