Enantioselective synthesis of β-hydroxy-α-amino acid esters by aldol coupling using a chiral quaternary ammonium salt as catalyst
作者:Manabu Horikawa、Jakob Busch-Petersen、E.J Corey
DOI:10.1016/s0040-4039(99)00636-x
日期:1999.5
A variety of chiral β-hydroxy-α-amino acids and derivatives thereof can be synthesized enantioselectively using the aldol reaction of an aldehyde, the glycinate 1 and the cinchonidine-derived catalyst 2, as indicated in Schemes 1 and 2 and Table 1.
Development of Highly Diastereo- and Enantioselective Direct Asymmetric Aldol Reaction of a Glycinate Schiff Base with Aldehydes Catalyzed by Chiral Quaternary Ammonium Salts
A highly efficient directasymmetricaldolreaction of a glycinate Schiff base with aldehydes has been achieved under mild organic/aqueous biphasic conditions with excellent stereochemical control, using chiral quaternary ammonium salt 1b as a phase-transfer catalyst. The initially developed reaction conditions, using 2 equiv of aqueous base (1% NaOH (aq)), exhibited inexplicably limited general applicability
Catalytic asymmetric synthesis of β-hydroxy-α-amino acid esters by direct aldol reaction of glycinate Schiff bases
作者:Naoki Yoshikawa、Masakatsu Shibasaki
DOI:10.1016/s0040-4020(02)00979-1
日期:2002.10
A catalyticasymmetricsynthesis of β-hydroxy-α-amino acid esters was developed using the directaldolreaction of glycinate Schiff bases with aldehydes. The reaction was catalyzed by heterobimetallic asymmetric complexes without preformation of enol silyl ethers from glycinate Schiff bases. anti-β-Hydroxy-α-amino acid esters were obtained as the major diastereomer in most cases, and moderate enantiomeric
The invention provides compounds of the Formula 1
1
wherein the definitions of m, n, R
1
, R
2
, R
3
, R
4
, R
5
, R
6
, R
7
, R
8
, R
9
, R
10
, R
11
, R
12
and R
13
are in the specification. These compounds are useful as antibacterial agents.